Next Article in Journal
Integrated Metabolomics and Transcriptomics Analyses Reveal the Candidate Genes Regulating the Meat Quality Change by Castration in Yudong Black Goats (Capra hircus)
Previous Article in Journal
Genome-Wide Identification, Expression and Interaction Analyses of PP2C Family Genes in Chenopodium quinoa
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
Journals
Genes
Volume 15
Issue 1
10.3390/genes15010042
genes-logo
Submit to this Journal Review for this Journal Propose a Special Issue
► Article Menu

Article Menu

share Share announcement Help format_quote Cite question_answer Discuss in SciProfiles thumb_up
...
Endorse textsms
...
Comment
first_page
settings
Order Article Reprints
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Article

QTL Mapping of Trichome Traits and Analysis of Candidate Genes in Leaves of Wheat (Triticum aestivum L.)

by
Hua Fan
1,2,†,
Jianchao Xu
1,†,
Dan Ao
1,
Tianxiang Jia
1,
Yugang Shi
1,
Ning Li
1,
Ruilian Jing
3 and
Daizhen Sun
1,*
1
College of Agronomy, Shanxi Agricultural University, Taigu, Jinzhong 030800, China
2
Experimental Teaching Center, Shanxi Agricultural University, Taigu, Jinzhong 030800, China
3
Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100000, China
*
Author to whom correspondence should be addressed.
†
These authors contributed equally to this work.
Genes 2024, 15(1), 42; https://doi.org/10.3390/genes15010042
Submission received: 1 December 2023 / Revised: 22 December 2023 / Accepted: 25 December 2023 / Published: 27 December 2023
(This article belongs to the Section Plant Genetics and Genomics)
Browse Figures
Versions Notes

Abstract

:
Trichome plays an important role in heat dissipation, cold resistance, water absorption, protection of leaves from mechanical damage, and direct exposure to ultraviolet rays. It also plays an important role in the photosynthesis, transpiration, and respiration of plants. However, the genetic basis of trichome traits is not fully understood in wheat. In this study, wheat DH population (Hanxuan 10 × Lumai 14) was used to map quantitative trait loci (QTL) for trichome traits in different parts of flag leaf at 10 days after anther with growing in Zhao County, Hebei Province, and Taigu County, Shanxi Province, respectively. The results showed that trichome density (TD) was leaf center > leaf tip > leaf base and near vein > middle > edge, respectively, in both environments. The trichome length (TL) was leaf tip > leaf center > leaf base and edge > middle > near vein. Significant phenotypic positive correlations were observed between the trichome-related traits of different parts. A total of 83 QTLs for trichome-related traits were mapped onto 18 chromosomes, and each one accounted for 2.41 to 27.99% of the phenotypic variations. Two QTL hotspots were detected in two marker intervals: AX-95232910~AX-95658735 on 3A and AX-94850949~AX-109507404 on 7D. Six possible candidate genes (TraesCS3A02G406000, TraesCS3A02G414900, TraesCS3A02G440900, TraesCS7D02G145200, TraesCS7D02G149200, and TraesCS7D02G152400) for trichome-related traits of wheat leaves were screened out according to their predicted expression levels in wheat leaves. The expression of these genes may be induced by a variety of abiotic stresses. The results provide the basis for further validation and functional characterization of the candidate genes.

1. Introduction

Trichome is a unique hairy structure appendage developed from plant epidermal cells [1,2]. The density and size are determined by the stage of growth and development as well as its location [3]. Trichome not only provides a natural physical barrier for plants, reducing damage from harmful organisms, freezing, UV radiation, and mechanical injury, but it also helps to minimize water loss and excessive accumulation and dissipation of heat within the plant [3,4,5,6,7]. At the same time, trichomes can synthesize, store, and secrete many important substances, working in conjunction with the pores, keratin, and wax on the surface to fulfill various protective functions [8,9,10,11]. Trichomes play a crucial role in the photosynthesis, transpiration, and respiration processes of plants [12]. In order to adapt to the growing environment, trichomes respond to abiotic environmental factors such as salt, drought, altitude, and light [13,14,15].
At present, many reports on genetic analysis of trichomes have focused on Arabidopsis, cucumber, soybean, cotton, Artemisia annua, tomato, corn, rice, and so on. Some key genes for the development of the trichome in the model plant Arabidopsis have been cloned, and the regulatory mechanism of trichome development has been gradually uncovered. The major regulatory genes known are transcription factors such as GL1 [16], TTG1 [17,18], GL3 [19,20], EGL3 [21], GL2 [22], TRY [23], CPC [24], and ETC1 [25] et al. Vernoud et al. (2009) [26] have separated some GLOSSY genes from maize associated with trichome and wax synthesis. The known rice genes mainly include OsWOX3B (GLR1, NUDA/GL-1/dep, GL5) [27,28,29,30], GL6 (HL6) [31,32,33], glr2 [34], GLR3 (OsSPL10) [35,36], gl1 [37,38], GLL [39], etc. Mutations of these genes often lead to the reduction or loss of rice leaf and glume surface trichomes. The trichome-related genes cloned in cucumber include TRIL and CsGL1, both of which encode proteins that contain the Leucine zipper domain and play an important regulatory role in the initiation and formation of trichome [40,41,42]. The genes in cotton, GoPGF [41], and GhMYB2A [43] regulate the initiation of trichome and fiber formation. Du et al. (2009) [44] mapped two QTLs that control leaf trichome density in soybeans, qtdD1b-2 and qtdH-2. The contribution of qtuH-2 to phenotypic variance was estimated to be 31.81% by molecular linkage groups and 29.4% by multiple interval mapping. Xing et al. (2013) [45] conducted a QTL analysis on the density and length of leaf pubescence in soybean by using two recombinant inbred lines, and they detected two major QTL, PD1-1 and PD12-1, associated with the density of leaf pubescence; the QTL contributed >20% to the phenotypic variance.
Because of the characteristics of the wheat genome, research on trichomes has been slower than that on other crops. Ringlund et al. (1968) [46] considered trichome traits in the leaves of cultivated wheat to be quantitative genetic traits. Maystrenko et al. (1976) [47] reported that the leaf trichomes of wheat seedlings are controlled by the major gene Hl1 located on chromosome 4B, and this gene was mapped to the short arm of chromosome 4B by Arbuzova et al. (1996) [48] by using telomere analysis. Taketa et al. (2002) [49] performed haplotype and telomere analyses and found another major gene that controls leaf trichomes on chromosome 7BS. Previous studies have also reported the mapping of trichome genes in the non-leaf organs of wheat. Maystrenko et al. (1992) [50] found that Pa controls auricle trichomes, with only a 30 cM gap between Hl1 and Pa. In addition, Blanco et al. (1998) [51] and Khlestkina (2002) [52] indicated that the trichomes on wheat glumes are regulated by the dominant gene Hg on the short arm of chromosome 1A. Furthermore, Love et al. (1924) [53] and Gaines (1926) [54] found that the dominant gene Hn that controls the trichomes on stem internodes is linked to the suppressor gene B1 of awn, and Sourdille et al. (2002) [55] mapped Hn to the long arm of chromosome 5A. Wan et al. (2015) [56] detected a major QTL for leaf sheath hairiness on 4DL in wheat, and the locus was significantly and positively correlated with some yield characteristics. Luo et al. (2020) [57] described two pairs of NILs for hairy glumes in common wheat. Chen Zhitong et al. (2021) [58] detected a major QTL conditioning trichome length and density on chromosome arm 4BL and developed near-isogenic lines targeting this locus in bread wheat.
In this study, trichome density and length in different parts of leaves in rain-fed and irrigation environments were calculated. By using a high-density linkage genetic map, the QTLs of trichome-related traits and candidate genes will provide insights for studying the molecular mechanism of trichome development in the wheat leaf.

2. Materials and Methods

2.1. Materials

2.1.1. Test Material

A wheat double haploid (DH) population, including 150 lines that were derived from a cross between Hanxuan 10 and Lumai 14, was used as test material in this study. All the DH lines and parents were grown in Zhao County (Heibei Province) and Taigu (Shanxi Province), China, in September 2019. For the experiment, a randomized block design was used with three repetitions. Wheat seeds were dibbled in 2 m rows, with 40 seeds per row and two rows per plot. In Zhao County, plants were irrigated before overwintering and at reviving, jointing, and mid-filling stages, with a total irrigation amount of 600 m3/hm2. In Taigu, the soil was irrigated to maintain available water before sowing, and rain-fed plants were not irrigated throughout the growth period. Precipitation over the whole growth period of wheat was 569.7 mm in Zhao County and 189 mm in Taigu. Taigu environment was named rain-fed, and Zhao County was irrigation.

2.1.2. Sample Collection and Preparation

On the day of flowering, the main stems of five random plants with uniform growth were selected and marked. Ten days after flowering, the entire blade of flag leaves was cut and immediately placed in a pre-cooled 3% glutaraldehyde fixative solution (in 0.1 M phosphate-buffered saline [PBS], Ph = 7.0) and stored in a refrigerator at 4 °C. The fixed leaves were washed three times with 0.1 M PBS, and samples were cut from the leaf tip, leaf center, and leaf base. Then, the samples were dehydrated with a gradient ethanol series of 30%, 50%, 70%, 80%, 90%, and 100% (twice) for 15 min each, followed by 75% tert-butanol (in ethanol solution) and 100% tert-butanol (twice) for 20 min each. The dehydrated samples were freeze-dried (JFD-320; JEOL Ltd., Akishima, Tokyo, Japan), stuck on stubs, and coated with platinum by using an ion sputtering device (JEM-6490LV; JEOL). The prepared samples were observed under a scanning electron microscope (JEM-6490LV; JEOL).

2.2. Methods

2.2.1. Trichome Trait Measurement and Data Analysis

Under the scanning electron microscope, three fields of view were selected from different parts (edge, middle [between leaf edge and main vein], and near vein) at the tip, center, and base of each leaf. A total of 27 fields of view were observed, and images were obtained at 100× magnitude. The Smile View software (Scanning electron microscopy analysis software of Japan Electron Optics Laboratory, JEOL) was used to measure the number of trichomes (then converted to trichome density, trichomes/mm2) and trichome length (μm). Correlation analysis between trichome traits of the wheat leaves was performed using SPSS v17.0 (SPSS Inc., Chicago, IL, USA).

2.2.2. QTL Mapping

The genetic map of the DH population was constructed by Jing Ruilian’s team at the Institute of Crop Science, Chinese Academy of Agricultural Sciences.
The map was constructed using a 660 K single-nucleotide polymorphism (SNP) array and simple sequence repeat (SSR) markers. It contained a total of 30 linkage groups with 1854 markers, including 1630 SNP markers and 224 pairs of SSR markers. It spanned 4082.44 cM of 21 wheat chromosomes, with a mean distance of 2.20 cM between markers [59].
On the basis of the complete interval mapping method, QTL detection was performed using IciMapping v4.0 (http://www.isbreeding.net/ (accessed on 15 November 2022)). The limit of detection (LOD) threshold was set to 2.5 [60], and QTLs with overlapping confidence intervals were integrated. QTL naming adopted Q + trait abbreviation + chromosome. If multiple QTLs were detected on the same chromosome for a specific trait, the number 1, 2, or 3 was added after the chromosome in the QTL name.

2.2.3. Prediction of Candidate Genes

Candidate genes in associated loci were predicted according to the reference genome sequence of ‘Chinese Spring’ wheat (IWGSC RefSeqv1.1), published by the International Wheat Genome Sequencing Consortium. Gene annotation was carried out by referring to the Ensembl Plants database (https://plants.ensembl.org/index.html (accessed on 9 October 2023)). We used a publicly available database, WheatOmics (http://wheatomics.sdau.edu.cn/ (accessed on 15 December 2023)) [61] (Ma et al., 2021), to obtain the expression profiles of all candidate genes.

3. Results

3.1. Distribution of Trichomes on Wheat Leaves

The different parts of the wheat leaves were observed (Supplementary Figure S1). TD was in the following order across the two environments: leaf center > leaf tip > leaf base under the two environments (Table 1). Under irrigation conditions, a significant difference (p < 0.01) in TD was observed between the leaf center, or tip, and the leaf base. Under rain-fed conditions, a significant difference (p < 0.01) in TD was observed between the leaf center and leaf base or tip. TD was in the following order across the two environments: near vein > middle > edge. A significant difference (p < 0.01) in TD was observed between the near vein, middle, and edge of each leaf part (Table 1, Figure 1). And it was found that, except for the leaf tip, TD at different leaf parts was significantly higher (p < 0.01) under rain-fed conditions than under irrigation. In particular, TD at the leaf base and edge was 20.47% and 40.37% higher under rain-fed conditions than under irrigation, respectively.
In both environments, TL varied in different parts of the wheat leaves (leaf tip > leaf center > leaf base), and the differences between various leaf parts were significant (p < 0.01). In each part of the leaves, TL varied at different parts (edge > middle > near vein), and the difference was significant between the edge and near vein (Table 1, Figure 1). TL tended to increase distinctly at different parts of wheat leaves under rain-fed conditions than under irrigation, and the differences were significant between the two environments (p < 0.01), except for the leaf center (Table 1).

3.2. Phenotypic Characteristics of Trichome-Related Traits in the DH Lines and Parents

The phenotypic values of TD and TL differed among the DH wheat lines and parents in the two environments. Under irrigation conditions, the male parent Lumai 14 had a higher TD than the female parent Hanxuan 10 at different parts of the wheat leaves, except for the leaf base. Under rain-fed conditions, Lumai 14 had a higher TD than Hanxuan 10 at all leaf parts. Furthermore, TL at different leaf parts was consistently higher for Hanxuan 10 than for Lumai 14 in both environments (Supplementary Table S1).
TD and TL of the DH lines were both higher under rain-fed conditions than under irrigation conditions. The mean values were between those of the two parents, but the range of variation showed remarkable bidirectional transgressive segregation. The coefficients of variation for TD ranged from 28.89% to 64.05%, and the coefficients of variation for TL ranged from 9.36% to 15.50%. Both TD and TL exhibited continuous variation, with less than 1 skewness and kurtosis (Supplementary Table S1), basically showing a normal distribution. The results indicate that TD and TL are quantitative traits controlled by polygenes.

3.3. Correlations of Trichome Traits in Wheat Leaves

In both environments, TD and TL showed a significantly positive correlation for all parts of the leaves. Under the rain-fed condition, TD showed a significantly positive correlation with TL for all parts. Under the irrigation condition, only TD at the leaf base-edge and TL at the leaf top-middle were significantly phenotypically positively correlated (Figure 2b).

3.4. QTL for Trichome Density in Wheat Leaves

A total of 49 QTLs for TD were detected in two environments. The phenotypic variance ranged from 2.41 to 27.99%, and the LOD value ranged from 2.57 to 22.32. The QTLs were distributed on 15 chromosomes, including 1D, 2A, 2B, 2D, 3A, 3B, 3D, 4D, 5A, 5B, 6A, 6B, 6D, 7B, and 7D, respectively. A total of 23 QTLs were obtained under irrigation, and the other 26 were rainfed. A total of 18 QTLs with positive effects were derived from the female parent Hanxuan 10 and distributed on nine chromosomes (2A, 2B, 3D, 5B, 6A, 6B, 6D, 7B, and 7D). The remaining 31 QTLs with negative effects were obtained from the male parent, Lumai 14, and distributed on eight chromosomes (1D, 2A, 2D, 3A, 3B, 4D, 5A, and 6A).
A total of 8 QTLs were detected in both environments. Among these QTLs, Qtd-3A-1 was detected at the leaf tip–middle, leaf base–edge, and leaf base–middle under rain-fed conditions, as well as the leaf tip–near vein under irrigation conditions, and was in the interval AX-95653062-AX-95235020 on chromosome 3A. Qtd-3A-4 was detected at the leaf center–middle and leaf center–near vein under rain-fed and leaf tip–middle under irrigation conditions and was in the interval AX-95235020-AX-95658735l. Qtd-3A-1 and Qtd-3A-4 were located at adjacent marker intervals. Qtd-3A-2 was identified at the leaf tip–near vein under rain-fed conditions as well as the leaf tip–edge and leaf center–near vein under irrigation conditions and was in the interval AX-95207768-AX-95679334. Qtd-3A-3 was detected at the leaf center–edge and leaf base–near vein under rain-fed and leaf base–middle irrigation conditions and was in the interval AX-95232910-AX-95207768. Qtd-3A-2 and Qtd-3A-3 were located at adjacent marker intervals.

3.5. QTL for Trichome Length in Wheat Leaves

A total of 34 QTLs for TL were detected in two environments. The phenotypic variance ranged from 5.52 to 18.46%, and the LOD value ranged from 2.50 to 7.53. The QTLs were distributed on 12 chromosomes, including 1A, 1B, 2A, 2B, 2D, 3B, 3D, 4A, 6B, 6D, 7B, and 7D, respectively. Approximately 16 QTLs were obtained under irrigation, and the other 18 were rainfed. A total of 29 QTLs with positive effects were derived from the female parent Hanxuan 10 and distributed on nine chromosomes (2A, 2B, 3B, 3D, 4A, 6B, 6D, 7B, and 7D). The remaining 5 QTLs with negative effects were obtained from the male parent, Lumai 14, and distributed on four chromosomes (1A, 1B, 2D, and 7B).
A total of 12 QTLs were detected in both environments. Among these QTLs, Qtl-7D-1 was detected at not only the leaf tip–middle and leaf base–middle under irrigation but also the leaf tip–middle and leaf center–near vein under rainfed conditions and was in the interva AX-95119219–Xgwm44 on chromosome 7D. Qtl-7D-4 was detected at the leaf center–near vein under irrigation and leaf tip–edge under rainfed conditions, and was in the interva AX-94850949–AX-95119219. Qtl-7D-1 and Qtl-7D-4 were located at adjacent marker intervals. Qtl-7D-3 was detected at the leaf center–middle under irrigation and leaf tip–near vein and leaf base–near vein under rainfed conditions and was in the interva AX-109879968–AX-95014724. Qtl-7D-5 was detected at the leaf base–edge under irrigation and leaf center–edge and leaf base–middle under rainfed conditions, and was in the interva AX-95014724–AX-109507404. Qtl-7D-3 and Qtl-7D-5 were located at adjacent marker intervals (Figure 3).

3.6. The Prediction of Candidate Genes

According to the reference genome sequence of ‘Chinese Spring Wheat’ (IWGSC RefSeqv1.1) published by the International Wheat Genome Sequencing Consortium, 285 genes were found in the interval of AX-95232910~AX-95658735 (18.8 cM) on chromosome 3A, and 150 genes were found in the interval of AX-94850949~AX-109507404 (15.1 cM) on chromosome 7D, and gene annotation was performed with reference to the Ensembl Plants database. WheatOmics was used to predict the expression of these genes in different tissues of Chinese Spring. We found that five genes (TraesCS3A02G406000, TraesCS3A02G414900, TraesCS3A02G440900, and TraesCS7D02G149200, TraesCS7D02G152400) were highly expressed in leaves, suggesting that these trichomes may have the function of regulating leaf trichome traits (Figure 4).
Then, the expression levels of these five genes under drought stress were predicted. The results showed that drought stress induced the expression of these genes. For example, the expression of TraesCS3A02G406000 was significantly increased after drought stress, and the expression of TraesCS3A02G414900, TraesCS3A02G440900, TraesCS7D02G149200, and TraesCS7D02G152400 was significantly decreased by drought induction (Figure 4).

4. Discussion

4.1. Genetic Effects of Trichome-Related Traits

In this study, we found that TD and TL of wheat leaves varied with different parts on the flag leaves of wheat, and the trend of each trait was similar across two different environments. These results indicated that trichome TD and TL were relatively stable traits in wheat that were less affected by the environment.
Tanksley (1996) [62] indicated that a major QTL refers to a QTL that explains >10% of the total phenotypic variance. In the present study, we detected 49 QTLs with additive effects on TD in the flag leaves of wheat, 12 of which each explained >10% of the phenotypic variance. In addition, 34 QTLs with additive effects on TL were detected in wheat, 11 of which each explained >10% of the phenotypic variance. According to these results, TD and TL in wheat were quantitative traits controlled by a combination of major and minor genes.

4.2. Linkage and Pleiotroty of QTL Related to Trichome Traits in Wheat

Various studies have found that QTL for closely related traits may be located in the same or nearby parts of chromosomes [63,64]. In this study, we found that under both environments, significant phenotypic positive correlations were observed between the trichome densities of different parts and between the trichome lengths of different parts. And 4 TD QTLs, Qtd-3A-1, Qtd-3A-2, Qtd-3A-3, and Qtd-3A-4, for more than one part of wheat leaves were detected between AX-95232910 and AX-95658735 under the two environments, respectively (Table 2 and Figure 3). Approximately 4 TL QTLs (Qtl-7D-1, Qtl-7D-3, Qtl-7D-4, and Qtl-7D-5) were also conducted between AX-94850949 and AX-109507404, respectively (Table 3 and Figure 3). Moncada et al. (2001) [65] believed that such specific regions related to multiple traits may have linkage or epistatic effects. Therefore, TD or TL in the different parts of wheat leaves may be controlled by the same gene or linkage genes.
Pleiotropism has been found in the QTL mapping and GWAS of multiple crops [66,67]. In this study, TD QTL, Qtd-7D-1, and TL QTL, Qtl-7D-2, were detected between AX-111529990-AX-95631292 at leaf top- middle and leaf top-near vein under rain-fed conditions, respectively. Qtd-7B and Qtl-7B-1 were detected in the interval Xwmc269.1-Xgwm297 at leaf top-edge and leaf central-edge under rain-fed conditions, respectively (Table 2 and Table 3). Therefore, pleiotropic sites controlling TD and TL of the trichome may be in the two regions.

4.3. Prediction of Candidate Genes Associated with Trichome Traits

In this study, 285 genes were found in the AX-95232910~AX-95658735 (18.8 cM) interval of chromosome 3A, and 150 genes were found in the AX-94850949~AX-109507404 (15.1 cM) interval of chromosome 7D. Five candidate genes (TraesCS3A02G406000, TraesCS3A02G414900, TraesCS3A02G440900, TraesCS7D02G149200, TraesCS7D02G152400) were screened according to their expression levels in different tissues of wheat Chinese spring varieties and after drought stress. These genes were mainly highly expressed in leaves and significantly induced by drought stress.
The candidate gene TraesCS3A02G406000 encodes a NAC domain protein. It has been reported in wheat that knocking out the NAC gene (TaNAC071-A) reduces wheat drought tolerance [68]. Under drought conditions, the expression of TraesCS3A02G406000 was significantly increased. TraesCS3A02G414900 is specifically expressed in wheat leaves, and its function is annotated as a cysteine-rich receptor kinase. Cysteine-rich receptor-like kinases (CRKs) belong to a large family of receptor-like kinases (RLKs) containing duf26, which play a key role in immunity, abiotic stress response, and growth and development [69]. Flor Cristina Arellano-Villagómez et al. found that Arabidopsis cysteine-rich receptor-like protein kinase CRK33 affects stomatal density and drought tolerance [70]. The expression of the TraesCS3A02G414900 gene was significantly decreased after drought stress. TraesCS3A02G440900 encodes a sec14p-like phosphatidylinositol transfer family protein. The main PI (phosphatidylinositol)/PC (phosphatidylcholine) transfer protein Sec14p in yeast coordinates lipid metabolism and protein transport of the Golgi complex [71]. The expression level of the gene TraesCS3A02G440900 was significantly reduced under drought conditions. TraesCS7D02G149200 is highly expressed in wheat leaves, and its functional annotation is the Dirigent protein. Dirigent protein has stereoselectivity to phenoxy coupling reactions in plants, so it plays an important role in the biosynthesis of bioactive natural products [72]. After drought stress, the expression of the TraesCS7D02G149200 gene was significantly reduced. The functional annotation of TraesCS7D02G152400 is glutathione peroxidase. Glutathione peroxidase 1 (GPx1) is an important cellular antioxidant enzyme. GPx1 regulates the balance between essential and harmful reactive oxygen species levels [73]. The expression of the TraesCS7D02G152400 gene was significantly reduced after drought stress.
The above five genes were not only specifically highly expressed in wheat leaves but also induced by drought stress. Studies have shown that wheat trichome traits have the effect of buffering direct sunlight and preventing water evaporation, thereby improving wheat drought resistance. In this study, these five candidate genes were significantly induced by drought stress. We speculated that these genes may also affect wheat drought tolerance by regulating wheat trichome traits. Therefore, in future studies, we will analyze whether these five genes have the function of regulating trichome traits through transgenic experiments, which will provide new insights into wheat drought tolerance research.

5. Conclusions

This study with 150 DH lines revealed that TD and TL were quantitatively inherited traits. Significant phenotypic positive correlations were observed between the trichome-related traits of different parts. A total of 83 QTLs were identified for TD and TL of wheat leaves in the two environments, which were distributed across 18 chromosomes and explained 2.41 to 27.99% of phenotypic variation. Two QTL hotspots were found in 3A and 7D. Five candidate genes were screened out, according to their expression levels in wheat leaves. The results provide the basis for further validation and functional characterization of the candidate genes.

Supplementary Materials

The following supporting information can be downloaded at: https://www.mdpi.com/article/10.3390/genes15010042/s1; Figure S1: Electron microscope images of trichome traits under full water (WW) and drought conditions (DS); Table S1: Phenotypic variation of trichome traits of DH lines and their parents at different part under two environments.

Author Contributions

Conception: H.F.; design: H.F. and D.S.; investigation: H.F. and J.X., D.A., T.J., Y.S. and N.L.; data curation: H.F., J.X. and T.J.; original draft preparation: H.F. and J.X.; writing: H.F. and J.X.; interpretation: D.S.; project administration: D.S. Resources: R.J. All authors have read and agreed to the published version of the manuscript.

Funding

This work was carried out with the support of “Key Research and Development Program Project in Shanxi Province (202102140601001)” and “Youth Science and Technology Innovation Fund of Shanxi Agricultural University (2004033)”.

Institutional Review Board Statement

Not applicable.

Data Availability Statement

Data are contained within the article and Supplementary Materials.

Acknowledgments

Thanks to Sun Daizhen, supervisor of this research group, for her guidance on this paper.

Conflicts of Interest

The authors declare no conflict of interest.

References

  1. Balkunde, R.; Pesch, M.; Hülskamp, M. Trichome patterning in Arabidopsis thaliana from genetic to molecular models. Curr. Top. Dev. Biol. 2010, 91, 299–321. [Google Scholar] [PubMed]
  2. Gao, Y.; Guo, J.Q.; Zhao, J.F. Molecular Mechanisms of Arabidopsis Trichome Development. Chin. Bull. Bot. 2011, 46, 119–127. [Google Scholar]
  3. Andrade, M.C.; Da Silva, A.A.; Neiva, I.P.; Oliveira, I.R.C.; De Castro, E.M.; Francis, D.M.; Maluf, W.R. Inheritance of type IV glandular trichome density and its association with whitefly resistance from Solanum galapagense accession LA1401. Euphytica 2017, 213, 52. [Google Scholar] [CrossRef]
  4. Houten, Y.M.; Glas, J.J.; Hoogerbrugge, H.; Rothe, J.; Bolckmans, K.J.F.; Simoni, S.; van Arkel, J.; Alba, J.M.; Kant, M.R.; Sabelis, M.W. Herbivory-associated degradation of tomato trichomes and its impact on biological control of Aculops lycopersici. Exp. Appl. Acarol. 2013, 60, 127–138. [Google Scholar] [CrossRef] [PubMed]
  5. Kariyat, R.R.; Smith, J.D.; Stephenson, A.G.; De Moraes, C.M.; Mescher, M.C. Non-glandular trichomes of Solanum carolinense deter feeding by Manduca sexta caterpillars and cause damage to the gut peritrophic matrix. Proc. R. Soc. B 2017, 284, 20162323. [Google Scholar] [CrossRef] [PubMed]
  6. Steede, W.T.; Ma, J.M.; Eickholt, D.P.; Drake-Stowe, K.E.; Kernodle, S.P.; Shew, D.; Danehower, D.A.; Lewis, R.S. The tobacco trichome exudate Z-abienol and its relationship with plant resistance to Phytophthora nicotianae. Plant Dis. 2017, 101, 1214–1221. [Google Scholar] [CrossRef] [PubMed]
  7. Vendemiatti, E.; Zsögön, A.; Silva, G.F.F.E.; De Jesus, F.A.; Cutri, L.; Figueiredo, C.R.F.; Tanaka, F.A.O.; Nogueira, F.T.S.; Peres, L.E.P. Loss of type-IV glandular trichomes is a heterochronic trait in tomato and can be reverted by promoting juvenility. Plant Sci. 2017, 259, 35–47. [Google Scholar] [CrossRef]
  8. Mcdowell, E.T.; Kapteyn, J.; Schmidt, A.; Li, C.; Kang, J.H.; Descour, A.; Shi, F.; Larson, M.; Schilmiller, A.; An, L.L.; et al. Comparative functional genomic analysis of Solanum glandular trichome types. Plant Physiol. 2011, 155, 524–539. [Google Scholar] [CrossRef]
  9. Ma, Y.L.; Wang, L.; Liu, Y.-X.; Lan, H.-Y. Uptates on Stress Tolerance of Main Accessory Structures and Their Synergetic Interaction in Desert Plants. Plant Physiol. J. 2015, 51, 1821–1836. [Google Scholar]
  10. Hegebarth, D.; Buschhaus, C.; Wu, M.; Bird, D.; Jetter, R. The composition of surface wax on trichomes of Arabidopsis thaliana differs from wax on other epidermal cells. Plant J. 2016, 88, 762–774. [Google Scholar] [CrossRef]
  11. Rakha, M.; Bouba, N.; Ramasamy, S.; Regnard, J.L.; Hanson, P. Evaluation of wild tomato accessions (Solanum spp.) for resistance to two-spotted spider mite (Tetranychus urticae Koch) based on trichome type and acylsugar content. Genet Resour. Crop Evol. 2017, 64, 1011–1022. [Google Scholar] [CrossRef]
  12. Hu, B.; Wan, Y.; Li, X.; Zhang, F.; Yan, W.; Xie, J. Phenotypic characterization and genetic analysis of rice with pubescent leaves and glabrous hulls. Crop Sci. 2013, 53, 1878–1886. [Google Scholar] [CrossRef]
  13. Hendrick, M.F.; Finseth, F.R.; Mathiasson, M.E.; Palmer, K.A.; Broder, E.M.; Breigenzer, P.; Fishman, L. The genetics of extreme microgeographic adaptation: An integrated approach identifies a major gene underlying leaf trichome divergence in Yellowstone Mimulus guttatus. Mol. Ecol. 2016, 25, 5647–5662. [Google Scholar] [CrossRef] [PubMed]
  14. Mazie, A.R.; Baum, D.A. Clade-specific positive selection on a developmental gene: BRANCHLESS TRICHOME and the evolution of stellate trichomes in Physaria (Brassicaceae). Mol. Phylogenet. Evol. 2016, 100, 31–40. [Google Scholar] [CrossRef] [PubMed]
  15. Ning, P.B.; Wang, J.H.; Zhou, Y.L.; Gao, L.F.; Wang, J.; Gong, C.M. Adaptional evolution of trichome in Caragana korshinskii to natural drought stress on the Loess Plateau, China. Ecol. Evol. 2016, 6, 3786–3795. [Google Scholar] [CrossRef] [PubMed]
  16. Oppenheimer, D.G.; Herman, P.L.; Sivakumaran, S.; Esch, J.; Marks, M.D. A myb gene required for leaf trichome differentiation in Arabidopsis is expressed in stipules. Cell 1991, 67, 483–493. [Google Scholar] [CrossRef] [PubMed]
  17. Alahakoon, U.I.; Taheri, A.; Nayidu, N.K.; Epp, D.; Yu, M.; Parkin, I.; Hegedus, D.; Bonham-Smith, P.; Gruber, M.Y. Hairy canola (Brasssica napus) re-visited: Down-regulating TTG1 in an AtGL3-enhanced hairy leaf background improves growth, leaf trichome coverage, and metabolite gene expression diversity. BMC Plant Biol. 2016, 16, 12. [Google Scholar] [CrossRef] [PubMed]
  18. Ioannidi, E.; Rigas, S.; Tsitsekian, D.; Daras, G.; Alatzas, A.; Makris, A.; Tanou, G.; Argiriou, A.; Alexandrou, D.; Poethig, S.; et al. Trichome patterning control involves TTG1 interaction with SPL transcription factors. Plant Mol. Biol. 2016, 92, 675–687. [Google Scholar] [CrossRef] [PubMed]
  19. Li, Y.Q.; Shan, X.T.; Gao, R.F.; Yang, S.; Wang, S.C.; Gao, X.; Wang, L. Two IIIf clade-bHLHs from freesia hybrida play divergent roles in flavonoid biosynthesis and trichome formation when ectopically expressed in Arabidopsis. Sci. Rep. 2016, 6, 30514. [Google Scholar] [CrossRef]
  20. Gao, C.H.; Li, D.; Jin, C.Y.; Duan, S.W.; Qi, S.H.; Liu, K.G.; Wang, H.C.; Ma, H.L.; Hai, J.B.; Chen, M.X. Genome-wide identification of GLABRA3 downstream genes for anthocyanin biosynthesis and trichome formation in Arabidopsis. Biochem. Biophys. Res. Commun. 2017, 485, 360–365. [Google Scholar] [CrossRef]
  21. Dai, X.M.; Zhou, L.M.; Zhang, W.; Cai, L.; Guo, H.Y.; Tian, H.N.; Schiefelbein, J.; Wang, S.C. A single amino acid substitution in the R3 domain of GLABRA1 leads to inhibition of trichome formation in Arabidopsis without affecting its interaction with GLABRA3. Plant Cell Environ. 2016, 39, 897–907. [Google Scholar] [CrossRef]
  22. Johnson, C.S.; Kolevski, B.; Smyth, D.R. TRANSPARENT TESTA GLABRA 2, a trichome and seed coat development gene of Arabidopsis, encodes a WRKY transcription factor. Plant Cell 2002, 14, 1359–1375. [Google Scholar] [CrossRef]
  23. Zheng, K.J.; Tian, H.N.; Hu, Q.N.; Guo, H.Y.; Yang, L.; Cai, L.; Wang, X.T.; Liu, B.; Wang, S.C. Ectopic expression of R3 MYB transcription factor gene OsTCL1 in Arabidopsis, but not rice, affects trichome and root hair formation. Sci. Rep. 2016, 6, 19254. [Google Scholar] [CrossRef]
  24. Schellmann, S.; Schnittger, A.; Kirik, V.; Wada, T.; Okada, K.; Beermann, A.; Thumfahrt, J.; Jürgens, G.; Hülskamp, M. TRIPTYCHON and CAPRICE mediate lateral inhibition during trichome and root hair patterning in Arabidopsis. EMBO J. 2002, 21, 5036–5046. [Google Scholar] [CrossRef]
  25. Wada, T.; Tominaga-Wada, R. CAPRICE family genes control flowering time through both promoting and repressing CONSTANS and FLOWERING LOCUS T expression. Plant Sci. 2015, 241, 260–265. [Google Scholar] [CrossRef]
  26. Vernoud, V.; Laigle, G.; Rozier, F.; Meeley, R.B.; Perez, P.; Rogowsky, P.M. The HD-ZIP IV transcription factor OCL4 is necessary for trichome patterning and anther development in maize. Plant J. 2009, 59, 883–894. [Google Scholar] [CrossRef]
  27. Li, J.; Yuan, Y.; Lu, Z.; Yang, L.; Gao, R.; Lu, J.; Li, J.; Xiong, G. Glabrous Rice 1, encoding a homeodomain protein, regulates trichome development in rice. Rice 2012, 5, 32. [Google Scholar] [CrossRef]
  28. Li, C. Cloning and Function Analysis of Glabrous Leaf Gene GLR3, GL5 and Fine Mapping of Hairy Leaf Gene HL6 in Rice; China Agricultural University: Beijing, China, 2016. [Google Scholar]
  29. Zhang, H.; Wu, K.; Wang, Y.; Peng, Y.; Hu, F.; Wen, L.; Han, B.; Qian, Q.; Teng, S. A WUSCHEL-like homeobox gene, OsWOX3B responses to NUDA/GL-1 locus in rice. Rice 2012, 5, 30. [Google Scholar] [CrossRef]
  30. Angeles-Shim, R.B.; Asano, K.; Takashi, T.; Shim, J.; Kuroha, T.; Ayano, M.; Ashikari, M. A WUSCHEL-related homeobox 3B gene, Depilous(dep), confers glabrousness of rice leaves and glumes. Rice 2012, 5, 28–30. [Google Scholar] [CrossRef]
  31. Sun, W.; Gao, D.; Xiong, Y.; Tang, X.; Xiao, X.; Wang, C.; Yu, S. Hairy Leaf 6, an AP2/ERF transcription factor, interacts with OsWOX3B and regulates trichome formation in rice. Mol. Plant 2017, 10, 1417–1433. [Google Scholar] [CrossRef]
  32. Zeng, Y.; Zhu, Y.; Lian, L.; Xie, H.; Zhang, J.; Xie, H. Genetic analysis and fine mapping of the pubescence gene GL6 in rice (Oryza sativa L.). Chin. Sci. Bull. 2013, 58, 2992–2999. [Google Scholar] [CrossRef]
  33. Xie, Y.; Yu, X.; Jiang, S.; Xiao, K.; Wang, Y.; Li, L.; Wang, F.; He, W.; Cai, Q.; Xie, H.; et al. OsGL6, a conserved AP2 domain protein, promotes leaf trichome initiation in rice. Biochem. Biophys. Res. Commun. 2020, 522, 448–455. [Google Scholar] [CrossRef] [PubMed]
  34. Wang, Y.; Chen, W.; Qin, P.; Huang, Y.; Ma, B.; Ouyang, X.; Chen, X.; Li, S. Characterization and fine mapping of GLABROUS RICE 2 in rice. J. Genet. Genom. 2013, 40, 579–582. [Google Scholar] [CrossRef] [PubMed]
  35. Song, H.-B.; Wang, B.; Chen, R.-J.; Zheng, X.-Y.; Yu, S.-B.; Lan, T. Genetic analysis and gene mapping of the glabrous leaf and hull mutant glr3 in rice (Oryza sativa L.). Hereditas 2016, 38, 1011–1018. [Google Scholar]
  36. Lan, T.; Zheng, Y.L.; Su, Z.L.; Yu, S.; Song, H.; Zheng, X.; Lin, G.; Wu, W. OsSPL10, a SBP-Box gene, plays a dual role in salt tolerance and trichome formation in rice (Oryza sativa L.). G3-Genes Genomes Genet. 2019, 9, 4107–4114. [Google Scholar] [CrossRef]
  37. Li, W.; Wu, J.; Weng, S.; Zhang, D.; Zhang, Y.; Shi, C. Characterization and fine mapping of the glabrous leaf and hull mutants (gl1) in rice (Oryza sativa L.). Plant Cell Rep. 2010, 29, 617–627. [Google Scholar] [CrossRef]
  38. Hong, J.; Wang, Q.Z.; Fu, H.W.; Wu, D.-x.; Shu, Q.y. Fine mapping and candidate gene analysis of glabrous leaf and hull gene (gl1) in rice (Oryza sativa L.). J. Nucl. Agric. Sci. 2011, 25, 1088–1093+1190. [Google Scholar]
  39. DongChen, W.H.; Zhang, X.L.; Zhu, Q. Cloning and subcellular localization of a new glabrous-leaf mutant gene GLL in rice (Oryza sativa L.). Mol. Plant Breed. 2015, 13, 716–726. [Google Scholar]
  40. Li, Q.; Cao, C.X.; Zhang, C.J.; Zheng, S.S.; Wang, Z.H.; Wang, L.N.; Ren, Z.H. The identification of Cucumis sativus Glabrous 1 (CsGL1) required for the formation of trichomes uncovers a novel function for the homeodomain-leucine zipper I gene. J. Exp. Bot. 2015, 66, 2515–2526. [Google Scholar] [CrossRef]
  41. Ma, D.; Hu, Y.; Yang, C.Q.; Liu, B.L.; Fang, L.; Wan, Q.; Liang, W.H.; Mei, G.F.; Wang, L.J.; Wang, H.P.; et al. Genetic basis for glandular trichome formation in cotton. Nat. Commun. 2016, 7, 10456. [Google Scholar] [CrossRef]
  42. Wang, Y.L.; Nie, J.T.; Chen, H.M.; Guo, C.L.; Pan, J.; He, H.L.; Pan, J.S.; Cai, R. Identification and mapping of Tril, a homeodomain-leucine zipper gene involved in multicellular trichome initiation in Cucumis sativus. Theor. Appl. Genet. 2016, 129, 305–316. [Google Scholar] [CrossRef] [PubMed]
  43. Guan, X.Y.; Pang, M.X.; Nah, G.; Shi, X.L.; Ye, W.X.; Stelly, D.M.; Chen, Z.J. miRNA and miRNA regulate homoeologous MYB2 gene functions in Arabidopsis trichome and cotton fibre development. Nat. Commun. 2014, 5, 3050. [Google Scholar] [CrossRef] [PubMed]
  44. Du, W.J.; Yu, D.Y.; Fu, S.X. Analysis of QTLs the trichome density on the upper and downer surface of leaf blade in soybean [Glycine max (L.) Merr.]. Agric. Sci. China 2009, 8, 529–537. [Google Scholar] [CrossRef]
  45. Xing, G.-N.; Liu, Z.-X.-N.; Tan, L.-M.; Yue, H.; Wang, Y.-F.; Kim, H.-J.; Zhao, T.-J.; Gai, J.-Y. QTL Mapping of Pubescence Density and Length on Leaf Surface of Soybean. Acta Agron. Sin. 2013, 39, 12–20. [Google Scholar] [CrossRef]
  46. Ringlund, K.; Everson, E.H. Leaf pubescence in common wheat, Triticum aestivum L.; and resistance to the cereal leaf beetle, Oulema melanopus (L.). Crop Sci. 1968, 8, 705–710. [Google Scholar] [CrossRef]
  47. Maystrenko, O.I. Identification and location of genes controlling leaf hairing in young plants of common wheat. Genetika 1976, 12, 5–15. [Google Scholar]
  48. Arbuzova, V.S.; Efremova, T.T.; Laikova, L.I.; Maystrenko, O.I.; Popova, O.M.; Pshenichnikova, T.A. The development of precise genetic stocks in two wheat cultivars and their use in genetic analysis. Euphytica 1996, 89, 11–15. [Google Scholar] [CrossRef]
  49. Taketa, S.; Chang, C.L.; Ishii, M.; Takeda, K. Chromosome arm location of the gene controlling leaf pubescence of a Chinese local wheat cultivar ‘Hong-mang-mai’. Euphytica 2002, 125, 141–147. [Google Scholar] [CrossRef]
  50. Maystrenko, O.I. Using of cytogenetic methods in studies of common wheat ontogenesis. In Ontogenetics of Higher Plants; Shtiitsa: Kishinev, Moldova, 1992; pp. 98–114. [Google Scholar]
  51. Blanco, A.; Bellomo, M.P.; Cenci, A.; De Giovanni, C.; D’Ovidio, R.; Iacono, E.; Laddomada, B.; Pagnotta, M.A.; Porceddu, E.; Sciancalepore, A.; et al. A genetic linkage map of durum wheat. Theor. Appl. Genet. 1998, 97, 721–728. [Google Scholar] [CrossRef]
  52. Khestkina, E.K.; Pestsovo, E.G.; Salina, E.; Röder, M.S. Molecular mapping and tagging of wheat genes using RAPD, STS and SSR markers. Cell. Mol. Biol. Lett. 2002, 7, 795–802. [Google Scholar]
  53. Love, H.H.; Craig, W.T. The inheritance of pubescent nodes in a cross between two varieties of wheat. J. Agric. Res. 1924, 28, 841–844. [Google Scholar]
  54. Gaines, E.F.; Carstens, A. The linkage of pubescent node and beard factors as evidenced by a cross between two varieties of wheat. J. Agric. Res. 1926, 33, 753–755. [Google Scholar]
  55. Sourdille, P.; Cadalen, T.; Gay, G.; Gill, B.; Bernard, M. Molecular and physical mapping of genes affecting awning in wheat. Plant Breed. 2002, 121, 320–324. [Google Scholar] [CrossRef]
  56. Wan, H.; Yang, Y.; Li, J.; Zhang, Z.; Yang, W. Mapping a major QTL for hairy leafsheath introgressed from Aegilops tauschii and its association with enhanced grain yield in bread wheat. Euphytica 2015, 205, 275–285. [Google Scholar] [CrossRef]
  57. Luo, W.; Liu, J.; Ding, P.; Li, C.; Liu, H.; Mu, Y.; Tang, H.; Jiang, Q.; Liu, Y.; Chen, G.; et al. Transcriptome analysis of near-isogenic lines for glume hairiness of wheat. Gene 2020, 739, 144517. [Google Scholar] [CrossRef] [PubMed]
  58. Chen, Z.; Zheng, Z.; Luo, W.; Zhou, H.; Ying, Z.; Liu, C. Detection of a major QTL conditioning trichome length and density on chromosome arm 4BL and development of near isogenic lines targeting this locus in bread wheat. Mol. Breed. 2021, 41, 10. [Google Scholar] [CrossRef] [PubMed]
  59. Shi, H.; Guan, W.; Shi, Y.; Wang, S.; Fan, H.; Yang, J.; Chen, W.; Zhang, W.; Sun, D.; Jing, R. QTL mapping and candidate gene analysis of seed vigor-related traits during artificial aging in wheat (Triticum aestivum). Sci. Rep. 2020, 10, 22060. [Google Scholar] [CrossRef]
  60. Li, L.; Peng, Z.; Mao, X.; Wang, J.; Li, C.; Chang, X.; Jing, R. Genetic insights into natural variation underlying salt tolerance in wheat. J. Exp. Bot. 2021, 72, 1135–1150. [Google Scholar] [CrossRef]
  61. Ma, S.W.; Wang, M.; Wu, J.H.; Guo, W.L.; Chen, Y.M.; Li, G.W.; Wang, Y.P.; Shi, W.M.; Xia, G.M.; Fu, D.L.; et al. WheatOmics: A platform combining multiple omics data to accelerate functional genomics studies in wheat. Mol. Plant 2021, 14, 1965–1968. [Google Scholar] [CrossRef]
  62. Tanksley, S.; Nelson, D.; Nelson, J.C. Advanced backcross QTL analysis: A method for the simultaneous discovery and transfer of valuable QTLs from unadaoted germlasm into elite breeding lines. Theor. Appl. Genet. 1996, 92, 191–203. [Google Scholar] [CrossRef]
  63. Fracheboud, Y.; Ribaut, J.M.; Vargas, M.; Messmer, R.; Stamp, P. Identification of quantitative trait loci for cold-tolerance of photosynthesis in maize (Zea mays L.). J. Exp. Bot. 2002, 53, 1967–1977. [Google Scholar] [CrossRef] [PubMed]
  64. Tuberosa, R.; Salvi, S.; Sanguineti, M.C.; Landi, P.; Maccaferri, M.; Conti, S. Mapping QTLs regulating morpho-physiological traits and yield: Case studies, shortcomings and perspectives in drought-stressed maize. Ann. Bot. 2002, 89, 941–963. [Google Scholar] [CrossRef] [PubMed]
  65. Moncada, P.; Martínez, C.; Borrero, J.; Chatel, M.; Gauch, H., Jr.; Guimaraes, E.; Tohme, J.; McCouch, S.R. Quantitative trait loci for yield and yield components in an Oryza sativa×Oryza rufipogon BC2F2 population evaluated in an upland environment. Theor. Appl. Genet. 2001, 102, 41–52. [Google Scholar] [CrossRef]
  66. Wen, T.; Wu, M.; Shen, C.; Gao, B.; Zhu, D.; Zhang, X.; You, C.; Lin, Z. Linkage and association mapping reveals the genetic basis of brown fibre (Gossypium hirsutum). Plant Biotechnol. J. 2018, 16, 1654–1666. [Google Scholar] [CrossRef] [PubMed]
  67. Liu, P.; Koizuka, N.; Martin, R.C.; Nonogaki, H. The BME3 (Blue Micropylar end 3) GATA zinc finger transcription factor is a positive regulator of Arabidopsis seed germination. Plant J. 2005, 44, 960–971. [Google Scholar] [CrossRef] [PubMed]
  68. Mao, H.; Li, S.; Chen, B.; Jian, C.; Mei, F.; Zhang, Y.; Li, F.; Chen, N.; Li, T.; Du, L.; et al. Variation in cis-regulation of a NAC transcription factor contributes to drought tolerance in wheat. Mol. Plant 2022, 15, 276–292. [Google Scholar] [CrossRef] [PubMed]
  69. Zhang, Y.; Tian, H.; Chen, D.; Zhang, H.; Sun, M.; Chen, S.; Qin, Z.; Ding, Z.; Dai, S. Cysteine-rich receptor-like protein kinases: Emerging regulators of plant stress responses. Trends Plant Sci. 2023, 28, 776–794. [Google Scholar] [CrossRef] [PubMed]
  70. Arellano-Villagómez, F.C.; Guevara-Olvera, L.; Zuñiga-Mayo, V.M.; Cerbantez-Bueno, V.E.; Verdugo-Perales, M.; Medina, H.R.; De Folter, S.; Acosta-García, G. Arabidopsis cysteine-rich receptor-like protein kinase CRK33 affects stomatal density and drought tolerance. Plant Signal. Behav. 2021, 16, 1905335. [Google Scholar] [CrossRef]
  71. Mousley, C.J.; Tyeryar, K.R.; Ryan, M.M.; Bankaitis, V.A. Sec14p-like proteins regulate phosphoinositide homoeostasis and intracellular protein and lipid trafficking in yeast. Biochem. Soc. Trans. 2006, 34 Pt 3, 346–350. [Google Scholar] [CrossRef]
  72. Meng, Q.; Kim, S.J.; Costa, M.A.; Moinuddin, S.G.A.; Celoy, R.M.; Smith, C.A.; Cort, J.R.; Davin, L.B.; Lewis, N.G. Dirigent protein subfamily function and structure in terrestrial plant phenol metabolism. Methods Enzymol. 2023, 683, 101–150. [Google Scholar]
  73. Handy, D.E.; Loscalzo, J. The role of glutathione peroxidase-1 in health and disease. Free Radic Biol. Med. 2022, 188, 146–161. [Google Scholar] [CrossRef]
Genes 15 00042 g001
Figure 1. The change trend lines of TD (a) and TL (b) for DH lines at different parts under two environments. LT-E: Leaf Top–Edge; LT-M: Leaf Top-Middle; LT-NV: Leaf Top-Near Vein; LC-E: Leaf Central-Edge; LC-M: Leaf Central-Middle; LC-NV: Leaf Central-Near Vein; LB-E: Leaf Base-Edge; LB-M: Leaf Base-Middle; LB-NV: Leaf Base-Near Vein. * and ** represent significant levels at p = 0.05 and p = 0.01 in the same row. TD: Trichome Density.
Figure 1. The change trend lines of TD (a) and TL (b) for DH lines at different parts under two environments. LT-E: Leaf Top–Edge; LT-M: Leaf Top-Middle; LT-NV: Leaf Top-Near Vein; LC-E: Leaf Central-Edge; LC-M: Leaf Central-Middle; LC-NV: Leaf Central-Near Vein; LB-E: Leaf Base-Edge; LB-M: Leaf Base-Middle; LB-NV: Leaf Base-Near Vein. * and ** represent significant levels at p = 0.05 and p = 0.01 in the same row. TD: Trichome Density.
Genes 15 00042 g001
Genes 15 00042 g002
Figure 2. Correlation of trichome density and trichome length of wheat leaves under rain-fed (a) and irrigation (b) conditions. * and ** represent significant and extremely significant levels, respectively.
Figure 2. Correlation of trichome density and trichome length of wheat leaves under rain-fed (a) and irrigation (b) conditions. * and ** represent significant and extremely significant levels, respectively.
Genes 15 00042 g002
Genes 15 00042 g003
Figure 3. Distributions of identified QTL for trichome traits on genetic linkage maps, The yellow lines are the QTL of trichome density, and the blue lines are the QTL of trichome length.
Figure 3. Distributions of identified QTL for trichome traits on genetic linkage maps, The yellow lines are the QTL of trichome density, and the blue lines are the QTL of trichome length.
Genes 15 00042 g003
Genes 15 00042 g004
Figure 4. Expression of candidate genes in various tissues (a). Expression of candidate genes under drought stress (b).
Figure 4. Expression of candidate genes in various tissues (a). Expression of candidate genes under drought stress (b).
Genes 15 00042 g004
Table 1. Comparisons of trichome traits of DH lines and parents at different parts of the leaf under two environments.
Table 1. Comparisons of trichome traits of DH lines and parents at different parts of the leaf under two environments.
PartTDTL
IrrigationRain-FedIrrigationRain-Fed
LT57.076 Aa61.745 Bb37.967 Aa40.754 ** Aa
LC60.813 Aa72.973 ** Aa36.49 2 Bb36.843 Bb
LB46.218 Bb55.680 ** Bb30.276 Cc32.634 ** Cc
E35.785 Bb50.231 ** Bb35.380 Aa37.264 ** Aa
M62.535 Aa70.075 ** Aa34.816 Aab36.717 ** Aab
NV64.930 Aa72.653 ** Aa34.540 Ab36.257 ** Ab
Note: The capital letter and small letter represent the difference at the 1% and 5% levels, respectively, in the same column; ** represent significant levels at p = 0.01 in the same row. TD: Trichome Density; TL: Trichome Length; LT: Leaf Top; LC: Leaf Central; LB: Leaf Base; E: Edge; M: Middle; NV: Near Vein.
Table 2. Additive-effect QTLs for trichome density under two environments.
Table 2. Additive-effect QTLs for trichome density under two environments.
QTLEnvironmentPartPositon (1)Flanking MarkerLOD (2)PVE (100%) (3)Add (4)
Qtd-2A-1Rain-fedLT-E38AX-110366793-AX-1115051459.7517.94−10.09
LT-NV5.4514.97−9.63
Qtd-2A-2IrrigationLT-E29Xgwm275-Xwmc517.5815.669.36
Qtd-2A-3IrrigationLC-E34AX-94695451-AX-951041548.8414.929−11.36
LC-M15.6521.83−16.71
LC-NV22.3227.993−17.94
Qtd-2A-4IrrigationLC-E101AX-111172526-AX-1117456164.847.6898.15
Qtd-2A-5IrrigationLC-M20Xcwm138.2-AX-1106866885.646.929.52
Qtd-2A-6IrrigationLC-M115AX-109532624-AX-1110461113.854.437.54
Qtd-2A-7IrrigationLC-NV28Xgwm425-Xpsp30888.799.92310.68
Qtd-3A-1Rain-fedLT-M96AX-95653062-AX-952350204.6912.37−8.94
LB-E992.989.06−5.05
LB-M3.309.24−6.43
IrrigationLT-NV965.1011.93−8.25
Qtd-3A-2Rain-fedLT-NV91AX-95207768-AX-956793346.1816.67−10.22
IrrigationLT-E922.905.34−5.52
LC-NV5.124.69−7.40
Qtd-3A-3Rain-fedLC-E90AX-95232910-AX-952077684.319.20−6.55
LB-NV4.42710.12−8.19
IrrigationLB-M894.7311.17−8.16
Qtd-3A-4Rain-fedLC-M100AX-95235020-AX-956587354.0910.15−6.67
LC-NV3.7610.39−7.78
IrrigationLT-M4.9710.37−8.26
Qtd-3A-5IrrigationLB-E83AX-110617585-AX-950722944.9211.68−8.07
Qtd-5A-1IrrigationLT-M0AX-109541070-AX-956302323.657.29−6.95
Qtd-5A-2IrrigationLT-NV20AX-95659236-AX-1099210263.076.89−6.37
Qtd-6A-1Rain-fedLB-M63AX-110543147-Xpsp30712.577.345.90
Qtd-6A-2IrrigationLC-E33Xcwm162-AX-1116192975.398.98−9.28
Qtd-2B-1Rain-fedLC-NV3Xcwm529-AX-944814824.0911.288.37
Qtd-2B-2IrrigationLT-M2AX-110555744-Xcwm5292.665.866.39
Qtd-3BRain-fedLT-E47AX-108735878-Xwmc2314.939.56−7.359
Qtd-5B-1Rain-fedLB-NV99Xgwm408-Xgwm6042.5775.976.27
Qtd-5B-2IrrigationLC-NV133AX-110945396-AX-1095815222.652.415.30
Qtd-5B-3IrrigationLB-NV249AX-109455033-AX-1088531922.768.607.08
Qtd-6BRain-fedLT-E75EST138.1-Xwmc3413.185.196.559
Qtd-7BRain-fedLT-E66Xwmc269.1-Xgwm2974.637.926.70
Qtd-1DIrrigationLC-NV86Xgwm337-AX-1105215473.193.223−6.08
Qtd-2D-1Rain-fedLC-E95AX-109879970-AX-1110664026.9315.24−8.42
Qtd-2D-2Rain-fedLB-NV89AX-110744761-Xwmc453.14.4710.64−8.45
Qtd-2D-3IrrigationLB-M116AX-94735076-AX-1119149663.538.13−6.94
Qtd-3DRain-fedLC-M216AX-109367171-AX-1115685093.097.555.76
LC-NV3.519.607.49
Qtd-4D-1IrrigationLC-E5AX-111475478-AX-896548304.947.86−8.25
LC-M75.776.913−9.39
LC-NV86.676.42−8.58
Qtd-4D-2IrrigationLB-E2AX-95659047-AX-1095160544.279.99−7.47
Qtd-6DRain-fedLT-E64AX-108849732-AX-1097792032.604.074.80
Qtd-7D-1Rain-fedLT-M108AX-111529990-AX-956312922.576.246.35
Qtd-7D-2Rain-fedLC-M101AX-95014724-AX-1095074045.3113.497.77
Note: (1) Position (cM) represents the distance to the first marker in the linkage group; (2) LOD: LOD value of each QTL; (3) PVE indicates the phenotypic variance explained by additive QTL; (4) Add represents the additive effect, positive value indicates the Hanxuan 10 allele having a positive effect on the trait, and a negative value represents the Lumai 14 allele having a positive effect.
Table 3. Additive effect QTLs for trichome length under two environments.
Table 3. Additive effect QTLs for trichome length under two environments.
QTLEnvironmentPartPosition (1)Flanking MarkerLOD (2)PVE (100%) (3)Add (4)
Qtl-1ARain-fedLC-E73Xcwm517-Xcwm5162.506.03−1.07
Qtl-2A-1Rain-fedLT-E45AX-94738148-Xgwm3284.4812.541.588
LT-M464.6612.231.29
Qtl-2A-2Rain-fedLT-NV37AX-95684521-AX-1118084443.188.531.05
Qtl-2A-3IrrigationLT-E43AX-94664242-AX-947381487.5318.462.83
LT-M443.569.531.65
Qtl-2A-4IrrigationLT-NV31Xgwm249-Xwmc632.787.211.29
Qtl-2A-5IrrigationLB-E95AX-110402534-AX-944506552.576.661.04
Qtl-4ARain-fedLC-M53AX-95145339-Xgwm6103.688.091.00
Qtl-1B-1Rain-fedLT-E118Xwmc44-AX-1087459312.958.16−1.28
Qtl-1B-2Rain-fedLC-NV42AX-94658630-AX-949351852.549.18−0.89
Qtl-2B-1Rain-fedLC-E54AX-108725943-AX-949401812.906.511.12
Qtl-2B-2Rain-fedLC-M58AX-108744217-AX-1087283312.575.520.84
Qtl-3BIrrigationLT-M34AX-108749246-AX-1116415352.917.231.44
Qtl-6BIrrigationLT-E128AX-111565328-AX-1105218243.136.631.70
Qtl-7B-1Rain-fedLC-E74Xwmc269.1-Xgwm2974.0210.37−1.39
Qtl-7B-2IrrigationLB-E165Xcwm466-AX-1110657054.1311.301.35
Qtl-7B-3IrrigationLB-NV145AX-108748008-AX-1088019073.5011.241.03
Qtl-2DIrrigationLC-M90Xwmc453.1-AX-1092610813.3910.79−1.48
Qtl-3DIrrigationLB-M161AX-111086016-AX-1110822093.968.491.08
Qtl-6DIrrigationLB-M0AX-111540806-AX-1095554843.467.241.01
Qtl-7D-1Rain-fedLT-M96AX-95119219-Xgwm446.0916.531.51
LB-M3.099.481.20
IrrigationLT-M964.2710.941.78
LC-NV955.6616.011.83
Qtl-7D-2Rain-fedLT-NV108AX-111529990-AX-956312923.9110.181.15
Qtl-7D-3Rain-fedLC-M98AX-109879968-AX-950147247.4817.431.48
IrrigationLT-NV1006.4317.702.05
LB-NV984.5314.771.19
Qtl-7D-4Rain-fedLC-NV94AX-94850949-AX-951192193.8814.141.12
IrrigationLT-E934.8110.602.17
Qtl-7D-5Rain-fedLB-E103AX-95014724-AX-1095074042.678.341.09
IrrigationLC-E1012.999.131.60
LB-M1034.9410.651.21
Note: (1) Position (cM) represents the distance to the first marker in the linkage group; (2) LOD: LOD value of each QTL; (3) PVE indicates the phenotypic variance explained by additive QTL; (4) Add represents the additive effect, positive value indicates the Hanxuan 10 allele having a positive effect on the trait, and a negative value represents the Lumai 14 allele having a positive effect. LT-E: Leaf Top-Edge; LT-M: Leaf Top-Middle; LT-NV: Leaf Top-Near Vein; LC-E: Leaf Central-Edge; LC-M: Leaf Central-Middle; LC-NV: Leaf Central-Near Vein; LB-E: Leaf Base-Edge; LB-M: Leaf Base-Middle; LB-NV: Leaf Base-Near Vein.
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.

Share and Cite

MDPI and ACS Style

Fan, H.; Xu, J.; Ao, D.; Jia, T.; Shi, Y.; Li, N.; Jing, R.; Sun, D. QTL Mapping of Trichome Traits and Analysis of Candidate Genes in Leaves of Wheat (Triticum aestivum L.). Genes 2024, 15, 42. https://doi.org/10.3390/genes15010042

AMA Style

Fan H, Xu J, Ao D, Jia T, Shi Y, Li N, Jing R, Sun D. QTL Mapping of Trichome Traits and Analysis of Candidate Genes in Leaves of Wheat (Triticum aestivum L.). Genes. 2024; 15(1):42. https://doi.org/10.3390/genes15010042

Chicago/Turabian Style

Fan, Hua, Jianchao Xu, Dan Ao, Tianxiang Jia, Yugang Shi, Ning Li, Ruilian Jing, and Daizhen Sun. 2024. "QTL Mapping of Trichome Traits and Analysis of Candidate Genes in Leaves of Wheat (Triticum aestivum L.)" Genes 15, no. 1: 42. https://doi.org/10.3390/genes15010042

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop