Search Results (148)

Bolting height is a key genetic trait that affects the stress tolerance, environmental adaptation, and winter survival of Brassica napus winter rapeseed. It is particularly important for enhancing winter survival in the arid–frigid regions. This study aimed to elucidate the genetic relationship between bolting height and cold stress tolerance, thereby supporting breeding for enhanced cold tolerance. Ninety-five winter rapeseed accessions were used in this study. Through both spring and autumn sowing trials, the dynamic changes in bolting height under different environments were systematically analyzed, and the genetic stability of bolting height as well as its correlation with cold tolerance were clarified. Bolting height showed consistent variation trends between spring and autumn sowing trials, exhibiting high genetic stability. It displayed an extremely significant negative correlation with cold tolerance: genotypes with lower bolting height possessed stronger cold tolerance. The regulatory mechanism underlying low bolting and cold tolerance was revealed at cellular and molecular levels. Low bolting accessions exhibited flat and broad shoot apical meristems, with small and compact cells, a high nucleoplasmic ratio, and indistinct vacuoles. The gibberellin synthesis gene BnaA06g24070D was downregulated, while the key cold-tolerant gene BnCBF5 was upregulated. Exogenous hormone treatment preliminarily verified the causal regulatory effect of bolting height on cold tolerance. In both spring and autumn sowing trials, bolting height at the initial flowering stage showed an extremely significant positive correlation with vernalization index, with correlation coefficients of 0.80 and 0.78, respectively. Lower bolting height corresponded to a smaller vernalization index and stronger temperature sensitivity. Moreover, bolting height at the initial flowering stage showed an extremely significant negative correlation with comprehensive cold tolerance scores, with correlation coefficients of −0.77 and −0.80, respectively. Low-bolt materials had significantly higher overwintering rates and comprehensive cold tolerance scores, as well as a markedly lower semi-lethal temperature (LT₅₀), compared with high-bolt accessions. Low-bolt accessions presented significantly prolonged bolting stage, bud stage, initial flowering stage, and whole growth durations, and their agronomic trait stability across years was significantly superior to that of high-bolt accessions. This study confirmed that low bolting height is a crucial breeding trait for the cold tolerance of winter rapeseed, and thus an important selection indicator for the cold tolerance improvement of winter rapeseed in arid–frigid regions in northern China. Full article

Tomato (Solanum lycopersicum L.) is a globally important vegetable crop and a key model species for studying reproductive development in other Solanaceae members with edible fleshy fruits, such as eggplant, sweet and hot peppers, and Physalis spp. The morphogenesis and patterning of tomato floral organs fundamentally determine fruit yield and quality. Recent advances in high-throughput sequencing and gene editing have significantly deepened our understanding of the molecular network regulating tomato reproductive development. This process, from the transition of vegetative shoot apical meristem to the inflorescence meristem, forming floral meristems with primordia of sepals, petals, stamens, carpels, and fruits, is precisely coordinated by a genetic network involving homeobox and other types of transcription factors, along with signaling pathways. This review systematically outlines the core regulatory network, with an emphasis on the MADS-domain transcription factor family and its associated ABCDE model. Integrating insights from hormone signaling and mutant phenotypes, we summarize the maintenance of inflorescence meristem identity, the specification of floral meristems, and the morphogenetic patterns and core gene regulatory mechanisms for each floral whorl in tomato. We further extend this framework to the flower–fruit continuum, examining how carpel development, floral meristem termination, and ovule differentiation influence fruit morphology, locule number, pericarp structure, and metabolic traits. Finally, we discuss the integration of floral organ development with molecular design breeding and formulate a forward-looking research agenda that translates floral regulatory mechanisms to breeding strategies for yield, uniformity, and fruit quality. This synthesis provides a theoretical foundation and genetic resources for the genetic improvement of tomato flower architecture and its underlying regulatory mechanisms. Full article

Isopentenyltransferase (IPT) is the rate-limiting enzyme in cytokinin biosynthesis and plays a critical role in plant acclimation to abiotic stress. To explore soybean IPT genes, we performed genome-wide identification, bioinformatics analysis, and molecular experimental validation to systematically characterize the features and functions of the soybean IPT (GmIPT) gene family. We identified 15 GmIPT genes in the soybean genome, which are unevenly distributed across 12 chromosomes; their evolutionary expansion is primarily driven by whole-genome duplication events. Phylogenetic analysis of soybean IPT proteins with those from Arabidopsis, rice and maize clustered them into four groups, exhibiting lineage-specific functional specialization. GmIPT genes exhibit significant variations in conserved motifs, gene structure, and cis-acting elements; their promoter regions are enriched in light-responsive, abiotic stress-responsive, and hormone-responsive elements, indicating their involvement in complex transcriptional regulatory networks. Tissue expression profiling revealed that GmIPT7 and GmIPT10 are highly expressed in various tissues, whereas GmIPT14 shows specific expression in flowers and the shoot apical meristem. Transcriptomic analysis and qRT-PCR validation demonstrated that GmIPT7, GmIPT10 and GmIPT15 respond differentially to drought, salt and low-temperature stress, with GmIPT15 exhibiting a transient upregulation at 3 h (p < 0.01) followed by a gradual decline to levels close to the pre-treatment control at 6–12 h under low-temperature stress. We further performed haplotype analysis of GmIPT15 and identified a putative elite haplotype (hap1) associated with cold tolerance based on low-temperature germination index assessment. This study provides useful insights for the future functional characterization of plant IPT genes and offers potential genetic resources and molecular markers that may support molecular-assisted breeding for soybean abiotic stress tolerance. Full article

Cauliflower (Brassica oleracea var. botrytis) curd formation is a highly complex developmental process governed by tightly coordinated genetic and physiological regulation. Here, we performed transcriptome sequencing of curd and peduncle tissues across multiple developmental stages, generating 171.52 Gb of high-quality data. Genes associated with photosynthesis and glucosinolate biosynthesis were strongly upregulated in the shoot apical meristem (SAM), highlighting substantial metabolic investment during the pre-initiation phase of curd morphogenesis. Key floral transition regulators, particularly AP2 and MADS-box transcription factors, were activated to drive the vegetative-to-reproductive switch and initiate curd primordia, ultimately giving rise to the arrested inflorescence architecture characteristic of cauliflower. Furthermore, hormone signaling pathways—including auxin (AUX), jasmonic acid (JA), and brassinosteroid (BR)—showed marked activation during SAM proliferation and peduncle elongation, underscoring their crucial roles in structural patterning. Collectively, our findings delineate an integrated regulatory network that links metabolic activity, hormone signaling, and developmental programs, providing novel molecular insights into curd formation and identifying potential breeding targets for the genetic improvement of Brassicaceae crops. Full article

Root suckering is a key mode of clonal propagation in white poplar group, such as aspens (Populus section Leuce), enabling rapid vegetative spread, yet the molecular triggers remain elusive. Here, we developed a rapid protocol that produces abundant root suckers with the root cutting of white poplar (Populus davidiana × P. bolleana) roots in greenhouse. Anatomical analyses and daily resolution transcriptomes resolved three sequential developmental stages: primordium initiation (Days 0–1), SAM (shoot apical meristem) establishment (Days 1–4), and organ differentiation/growth (Days 4–6). Weighted gene co-expression network analysis revealed that auxin- and cytokinin-mediated signaling, integrated with nitrogen metabolism, orchestrates SAM formation and maintenance. Exogenous application of 0.5–1.0 mg L⁻¹ NAA suppressed sucker emergence by 48–60%, whereas inhibition of cytokinin biosynthesis with lovastatin reduced initiation by 60%. These data establish that auxin negatively regulates and cytokinin is indispensable for de novo shoot apical meristem establishment during poplar root-suckering, underscoring that a precise auxin–cytokinin balance governs the timing and extent of this developmental process. Cambial regulators WUSCHEL-Related Homeobox 4-1/2 (WOX4-1/2), together with core meristem regulators WUSCHEL (WUS) and SHOOT MERISTEMLESS (STM), were specifically induced during SAM establishment that underpin vascular integration between the nascent shoot and the parental root. These results uncover the molecular pathway controlling root suckering and provide potential targets for molecular breeding to either enhance or suppress root suckering in Populus. Full article

Cymbidium faberi Rolfe is a Chinese flower famous due to its beautiful floral pattern and strong floral scent and is also a threatened terrestrial orchid. Moreover, the traditional propagation method through tillers and symbiotic seed germination with the correct fungus under nature conditions could not meet conservation and commercial needs. Here, an efficient procedure for asymbiotic seed germination and in vitro seedlings development of C. faberi was successfully established through evaluation of time of seed collecting, seed pretreatments, light conditions and composition of culture media, respectively. Seed pretreatment with 1% NaClO for 30 min, dark culture on 1/4 MS medium containing 0.5 mg·L⁻¹ 6-BA and 0.1 mg·L⁻¹ NAA for 30 days and subsequent long day condition (14 h light/10 h dark photoperiod) culture on this medium for 30 days could obviously enhance the seed germination rate of C. faberi. The highest germination rate (85.0 ± 0.79%) was achieved when seeds were collected at 120 d after cross-fertilization, and then germination percentages progressively decreased. Furthermore, histological analyses from protocorm formation to seedling growth were explored. This study not only offers a reliable and scalable system for mass propagation to meet commercial and conservation demands but also serves as a foundational reference for physiological and molecular studies in Cymbidium and related orchids. Full article

Climate change and widespread micronutrient deficiencies threaten food security in the semi-arid tropics. Finger millet (Eleusine coracana (L.) Gaertn.) is a climate-resilient “nutri-cereal” rich in calcium, zinc, iron and dietary fiber. Finger millet is a promising crop for addressing climate stress and nutrient deficiencies. However, it remains under-explored and relatively neglected in breeding and genetic improvement programs compared to major cereals. This review synthesizes recent biotechnological advances and outlines future directions for finger millet improvement. Foundational resources now include a chromosome-scale reference genome, expanding transcriptome, diverse global germplasm panels, and growing reports of genome-wide association studies (GWAS) and quantitative trait loci (QTL) for key traits including yield, stress tolerance, blast resistance, and mineral contents. Tissue culture studies reported both somatic embryogenesis and direct regeneration. Stable genetic transformation has been achieved in finger millet via Agrobacterium-mediated methods, particularly using shoot apical meristem (SAM) and by biolistics (gene gun) methods. Genome editing has not yet been reported, but we propose a practical roadmap leveraging reported tissue culture genetic transformation protocols for applying the CRISPR/Cas system for trait improvements. Using new biotechnological methods, along with pangenome, speed breeding, and helpful microbiomes, will make finger millet a strong and reliable food source for the future. Full article

Soybean (Glycine max (L.) Merr.) is a vital crop for the global supply of protein and oil, with its growth and development being regulated by genetic, hormonal, and environmental factors, particularly light and hormone signaling. The Small Auxin-Up RNA (SAUR) gene family plays a crucial role in plant growth regulation; however, the molecular mechanisms by which GmSAUR46 integrates photosynthesis and hormonal networks in soybean remain unclear. In this study, we focused on GmSAUR46b (Glyma.19G182600.1) and employed CRISPR/Cas9-mediated knockout and 35S-driven overexpression lines, alongside wild-type soybean (cv. Williams 82), to investigate its function. RNA sequencing (RNA-Seq) was conducted on shoot apical meristems, stems, and leaves at three developmental stages (V1, V2, V3), followed by transcriptomic analyses, including differential gene expression (DEG) identification and functional enrichment (GO, KEGG, KOG). Anatomical studies using paraffin sectioning and scanning electron microscopy (SEM) assessed the leaf midrib thickness and stem trichome density under varying light conditions. The transcriptomic results revealed DEGs enriched in pathways related to cell wall metabolism, hormone response, and photosynthesis. Anatomical analyses demonstrated that GmSAUR46b specifically regulates the leaf midrib thickness and stem trichome density in a light-dependent manner: under shade, the overexpression lines exhibited increased midrib thickness and trichome density, whereas the knockout lines showed reduced trichome density. Additionally, novel transcripts associated with stress resistance, hormone metabolism, and photosynthesis were identified, expanding the known soybean gene repertoire. Collectively, GmSAUR46b functions as a central hub integrating light signals with hormone and cell wall pathways to modulate soybean growth, particularly leaf and stem traits. This study advances understanding of SAUR gene function in soybean and provides valuable insights for molecular breeding aimed at improving adaptability and yield under diverse environmental conditions. Full article

9-cis-epoxycarotenoid dioxygenases (NCEDs), serving as the rate-limiting enzymes in abscisic acid (ABA) biosynthesis, play a pivotal role in regulating plant growth and development, as well as responses to abiotic stresses. Despite their agronomic importance, the molecular dialog between ABA signaling and vernalization, a cold-induced switch from vegetative to reproductive growth in wheat, remains poorly characterized, particularly regarding the TaNCED gene family members. Here, we systematically identified 13 TaNCED members in hexaploid wheat, followed by multi-omics characterization encompassing physicochemical properties, exon–intron architectures, conserved catalytic domains, protein motifs, and cis-acting elements. By analyzing transcriptome data from vernalization treatments, we profiled the expression patterns of TaNCED genes during vernalization. Notably, TaNCED5-6A, TaNCED5-6B, and TaNCED5-6D exhibited significant upregulation in vernalized leaves and tiller buds, while maintaining basal expression in the shoot apical meristem, the site of floral induction. This tissue-specific expression pattern implicates their specialized role in mediating vernalization responses via ABA biosynthesis. Collectively, our findings provide novel insights into the regulatory mechanisms of ABA-mediated vernalization in wheat and offer valuable targets for vernalization efficiency in cereal breeding programs. Full article

Soybean (Glycine max (L.) Merr.) flowering time and plant height are critical agronomic traits that significantly influence yield and environmental adaptability. To clarify the regulatory mechanisms of flowering-related genes and their associations with plant height, a genome-wide identification of such genes in soybean were performed. This analysis used Arabidopsis thaliana flowering genes as references, employing BLASTP searches and pathway classification. All of the identified flowering-related genes were classified into eight regulatory pathways, with the photoperiod pathway (Ph) being the most prominent. Evolutionary and expression analyses revealed that core regulators (e.g., GmFTs, GmSOC1s) are conserved across pathways and are preferentially expressed in shoot apical meristems (SAMs). Additionally, both flowering-related genes and key hormones (e.g., IAA, GA, ABA) exhibited rhythmic responses to light signals. CRISPR-Cas9-mediated validation confirmed that genes GmSAUR46b regulates both flowering time and plant height, as mutants of this gene showed early flowering and reduced height. Notably, a large proportion of previously mapped flowering genes overlapped with our identified ones, while some remained undetected, likely due to whole-genome duplication and adaptive evolution, which generate new regulatory networks. Most of the identified flowering-related genes, however, have not been mapped, which highlights substantial uncharacterized potential in soybean flowering and plant height regulation. This provides a valuable molecular framework to guide soybean molecular breeding for enhanced yield and environmental adaptability. Full article

Loquat (Eriobotrya japonica), an important subtropical fruit crop, blooms in autumn/winter, which is distinctive compared with other fruit trees such as apple, pear, and peach in Rosaceae. Currently, alternative splicing (AS) of flowering time genes remains understudied in loquat. In this study, full-length transcriptome sequencing of mixed tissues composed of leaves and shoot apical meristems/flower buds was performed and analyzed. A total of 94,194 high-quality isoforms and 44,186 complete open reading frames (ORFs) were obtained out of the 41.79 Gb of subread data. Further analysis revealed 25,988 AS events among 7461 genes, of which the most abundant type was intron retention (IR) occupying 55.32%. Importantly, 197 loquat genes homologous to Arabidopsis or Rosaceae flowering time genes were found to be alternatively spliced, including an important player CONSTANS (EjCO1) that contained three different isoforms (EjCO1-1, EjCO1-2, and EjCO1-3). To investigate the effect of AS on gene function, we overexpressed the three EjCO1 isoforms in Arabidopsis. The results showed that overexpression of EjCO1-1 and EjCO1-3 significantly promoted early flowering of transgenic Arabidopsis plants, whereas overexpressing EjCO1-2 did not significantly change the flowering time. Dual-luciferase reporter assays showed that EjCO1-1 and EjCO1-3 could significantly activate the expression of FLOWERING LOCUS T (EjFT2), while EjCO1-2 had no significant effect on the promoter activity of EjFT2. The results from this study systematically cataloged AS events of flowering time genes and illustrated the important effect of AS on gene functions, which provides insights into the molecular regulation of flowering time by AS in loquat. Full article

Background: Transcription factors (TFs) critically regulate gene expression, orchestrating plant growth, development, and stress responses. The conserved IDD (INDETERMINATE DOMAIN) TF family modulates key developmental processes, including root, stem, and seed morphogenesis. Dendrocalamus latiflorus Munro, an economically vital sympodial bamboo in southern China, suffers significant yield losses due to prevalent bamboo shoot abortion, impacting both edible shoot production and timber output. Despite the documented roles of IDD TFs in shoot apical meristem expression and lateral organ regulation, their genome-wide characterization in D. latiflorus remains unstudied. Methods: Using IDD members from Arabidopsis thaliana, Oryza sativa, and Phyllostachys edulis as references, we identified 45 DlIDD genes in D. latiflorus. Comprehensive bioinformatics analyses included gene characterization, protein physicochemical assessment, phylogenetic reconstruction, and examination of gene structures/conserved domains. Differential expression of DlIDD genes was profiled between dormant and sprouting bamboo shoots to infer putative functions. Results: The 45 DlIDD genes were phylogenetically classified into three subfamilies and unevenly distributed across 34 chromosomes. Whole-genome duplication (WGD) events drove the expansion of this gene family. Promoter analyses revealed enriched cis-regulatory elements associated with hormone response and developmental regulation. Functional analyses suggested potential roles for DlIDD genes in bamboo shoot development. Conclusions: This study provides a foundation for future research to elucidate the functions of IDD TFs and their regulatory mechanisms in bamboo shoot morphogenesis and lateral bud development within woody monocots. Full article

In this study, the effect of growth regulators on shoot proliferation and rooting were evaluated to develop an efficient micropropagation protocol for the Cannabis sativa L. cultivars ‘Cherry Soda’ and ‘Purple’. Apical meristems were isolated from actively growing shoots of stock plants and transferred to Driver and Kuniyuki Walnut (DKW) culture medium containing either 0.0, 0.5, 1.0, 2.0, or 5.0 μM meta-Topolin to study their shoot proliferation response. Resulting shoot cultures were transferred to medium containing varying levels of Indole Acetic Acid (IAA), Indole Butyric Acid (IBA), or Naphthalene Acetic Acid (NAA), solely or in combination, and were subjected to a 10-day dark incubation followed by a 16 h/8 h light/dark period to identify the best treatment for root production. Among the different shoot proliferation treatments studied, the maximum number of shoots was produced on the control medium that was devoid of any meta-Topolin. Cultures grown on medium containing 5.0 μM meta-Topolin exhibited hyperhydricity, where shoots appeared translucent and pale green in color; were characterized by water-soaked lesions; and leaves appeared curled and brittle in contrast to healthy looking cultures. Among the various rooting treatments studied, shoots grown in the dark for 10 days exhibited the highest frequency of rooting on medium containing 4.0 μM NAA or 6.0 μM IBA + 1.0 μM NAA. Full developed plants with a robust shoot and root system were transferred to soil, acclimatized under conditions for high humidity, and then transferred to ambient conditions in 4 weeks. The micropropagation protocol developed here allows for rapid multiplication of disease-free plants in C. sativa cultivars. Full article

Flowering is a key agronomic trait that directly influences the yield of the tea-oil tree (Camellia oleifera). Floral initiation, which precedes flower bud differentiation, represents a critical developmental stage affecting the flowering outcomes. However, the molecular mechanisms underlying floral initiation in C. oleifera remain poorly understood. In this study, buds from five key developmental stages of a 12-year-old C. oleifera cultivar ‘changlin53’ were collected as experimental samples. Scanning electron microscopy was employed to identify the stage of floral initiation. UPLC-MS/MS was used to analyze endogenous gibberellin (GA) concentrations, while transcriptomic analysis was performed to reveal the underlying transcriptional regulatory network. Six GA types were detected during floral initiation and petal development. GA₄ was exclusively detected at the sprouting stage (BII), while GA₃ was present in all samples but was significantly lower in BII and the flower bud primordium formation stage (BIII) than in the other samples. A total of 64 differentially expressed genes were concurrently enriched in flower development, reproductive shoot system development, and shoot system development. Weighted gene co-expression network analysis (WGCNA) identified eight specific modules significantly associated with different developmental stages. The magenta module, containing Unigene0084708 (CoFT) and Unigene0037067 (CoLEAFY), emerged as a key regulatory module driving floral initiation. Additionally, GA20OX1 and GA2OX8 were identified as candidate genes involved in GA-mediated regulation of floral initiation. Based on morphological and transcriptomic analyses, we conclude that floral initiation of C. oleifera is a continuous regulatory process governed by multiple genes, with the FT-LFY module playing a central role in the transition from apical meristem to floral meristem. Full article

Polyamine oxidase (PAO) is an important enzyme that functions in the catabolism of polyamines. While plant PAOs have been studied in several species, there is a lack of research on this gene family in soybean (Glycine max L.), one of the major food crops worldwide. Here, a genome-wide analysis identified 16 GmPAOs from the soybean genome, which were unevenly distributed in nine soybean chromosomes and were then phylogenetically classified into three groups. Collinearity analysis identified 17 duplicated gene pairs from the GmPAO family, and their Ka/Ks values were all less than one, indicating that the GmPAO family has undergone purifying selection during evolution. Analyses of the conserved motif and gene structure revealed the sequence differences among the GmPAOs of the three groups, suggestive of their functional differentiation. Additionally, the prediction of the secondary and tertiary structure of the GmPAOs provided a further basis for revealing their biological functions. A number of cis-acting elements relevant to development, phytohormone, and stress response were discovered in the promoter regions of the GmPAOs, which might be responsible for their functional diversities. Expression pattern analysis indicated that more than half of the GmPAOs showed preference in flower, two showed specificity in stem and shoot apical meristem, whereas four were barely expressed in all samples. Expression profiling of the GmPAOs also revealed that they were involved in the response to abiotic stresses, including cold, drought, and especially submergence stress. All these results lay an important foundation for further characterizing the functional roles of GmPAOs in soybean development and response to abiotic stresses. Full article