Search Results (46)

As a class of glutathione-dependent oxidoreductases, glutaredoxins (GRXs) play a central role in maintaining cellular redox homeostasis, thereby influencing diverse biological processes including growth, development, and stress adaptation in plants. This study identified 36 GRX genes in Litsea cubeba through whole-genome analysis. Phylogenetic classification placed them into four subfamilies (CC-, CGFS-, CPYC-type, and a species-specific SS branch), consistent with patterns in model plants like Arabidopsis thaliana and Oryza sativa, indicating evolutionary conservation of GRX core motifs. Genomic analyses including chromosomal location, collinearity, and gene structure revealed family evolution features. Expression profiling showed 11 LcGRX genes were flower-specific, with marked differential expression during stamen (M2) and pistil (F2) degeneration, supporting their roles in sexual dimorphism. Functional assays confirmed that floral highly expressed LcGRX12 directly interacts with TGA transcription factor LcTGA10, similar to its Arabidopsis homolog ROXY1. This study reveals the GRX-TGA module’s role in floral organ development in L. cubeba, offering insights into redox-mediated sex differentiation in Lauraceae and providing candidate genes for molecular breeding. Full article

The floral morphology of Rosa chinensis significantly influences its ornamental value. However, the molecular mechanisms underlying specific floral types remain poorly understood. Viridiflora, a stable genetic variant of R. chinensis, exhibits homeotic transformation of floral organs into sepal-like structures, providing a valuable model for studying floral organ identity and development. In this study, Viridiflora was compared with Old Blush to elucidate floral development through morphological observation, transcriptomic profiling, and functional genetics. Four distinct developmental stages were defined, encompassing the formation of sepal, petal, stamen, and pistil primordia. Transcriptome analysis identified candidate genes associated with the Viridiflora phenotype, among which RcAGAMOUS2 (RcAG2) and RcFRUITFULL (RcFUL) were selected for in-depth functional characterization. The proteins encoded by these two genes are hydrophilic, lack signal peptides and transmembrane domains, and contain multiple phosphorylation sites. They feature typical MADS-box family domains and show close phylogenetic affinity to Rosa rugosa. Subcellular localization showed their nuclear presence. Heterologous overexpression of RcAG2 and RcFUL in Arabidopsis resulted in notable phenotypic alterations: RcAG2 caused petal reduction and stamen exposure, while RcFUL led to greenish, leaf-like petals with pigmentation gradients, increased sepal number, and failed seed set. Conclusion: These results suggest that RcAG2 and RcFUL play key roles in floral organ development through genetic regulation, providing a theoretical foundation for further research on floral development in R. chinensis. Full article

Efficiency in vitro regeneration is a crucial prerequisite for the application of New Nenomics Techniques (NGTs) in grapevine (Vitis vinifera L.) for improving resistance to biotic and abiotic stresses. This is especially true given that their management must be addressed sustainably, considering the impact of climate change. Unfortunately, in vitro plant regeneration and the establishment of embryogenic calluses are two genotype-dependent processes. Up to now, extensive research has been conducted on major international cultivars, whereas studies on the application of in vitro protocols for autochthonous cultivars remain limited. In this study, protocols for the acquisition of embryogenic calluses were applied on the most relevant Sicilian grapevine cultivars: the red-skinned ‘Frappato’, ‘Nerello mascalese’, and ‘Nero d’Avola’, and the white-skinned ‘Grillo’, ‘Carricante’, and ‘Catarratto’. Stamens and pistils were cultured in two different induction media (PIV and MSII) and at three stages (mother cells in the late premeiotic phase, tetrads, and mature pollen) to induce embryogenic calluses. Five thousand explants per cultivar were cultured, forming calluses in four selected cultivars. Plantlets were successfully generated from calluses of ‘Carricante’, ‘Frappato’, and ‘Nero d’Avola’. Moreover, protoplasts were isolated from ‘Frappato’ and ‘Nero d’Avola’. Our results establish a critical foundation for developing successful regeneration protocols for the future application of NGTs in Sicilian grapevine cultivars. Full article

Asteraceae, as the largest angiosperm family, has an architecturally complex capitulum (inflorescences) composed of heteromorphic florets with distinct morphologies and functions. AGAMOUS (AG) MADS-box transcription factors act as key regulators in flower development and are essential for the formation of the characteristic capitulum and florets. To explore the potential functions of the AG genes in Asteraceae, we conducted a genome-wide identification and analysis of 52 AG-like genes across 22 species within this family. Additionally, we studied the functions of the Tagetes erecta class C genes TeAG1 and TeAG2 by introducing these genes into T. erecta and Nicotiana tabacum. Gene structure and phylogenomic analyses indicated that AG-like genes may have conserved and specific biological functions in Asteraceae plants. Phenotypic analyses revealed that the T. erecta class C genes TeAG1 and TeAG2 played a conserved and redundant role in regulating stamen and carpel development. The simultaneous downregulation of TeAG1 and TeAG2 led to the homeotic transformation of both stamens and carpels into corolla-like structures. However, silencing TeAG1 or TeAG2 individually in T. erecta did not affect any floral organ development. Furthermore, the ectopic expression of TeAG1 and TeAG2 in N. tabacum resulted in the transformation of sepals into pistils and corollas into stamens, respectively. Additionally, qRT-PCR analyses revealed that TeAG1 and TeAG2 repressed the expression of class A genes. Our findings expand our understanding of the function of class C genes within Asteraceae and provide strategies for breeding double-flower cultivars. Full article

Michelia ‘Xin’ is an evergreen rare ornamental tree species that undergoes FBD only once but blooms twice a year. However, the molecular mechanisms controlling its FBD process remain largely unknown. This study characterized the FBD process and delved into the key molecular regulatory mechanisms through transcriptomic and metabolomic analyses of developing flower buds. FBD in Michelia ‘Xin’ was characterized into five stages, including vegetative (T1), floral meristem transition (T2), tepal primordia differentiation (T3), stamen primordia differentiation (T4), and pistil primordia differentiation (T5). Analyses revealed a stage-specific metabolic and transcriptional regulation of FBD, with increasing numbers of differential metabolites and a decreasing number of DEGs from T1 to T5. Most phytohormone and transcription factor-related DEGs were highly induced from T2. The down-regulation of dormancy-associated protein homologs and CONSTANS-LIKE proteins associated with significant induction of flowering-promoting factor, CLAVATA3, trichome birefringence-like, and GRAVITROPIC IN THE LIGHT proteins was essential for the induction and reproductive organs’ development. Porphyrin biosynthesis, chlorophyll a-b binding proteins, DNA replication, flavonoid biosynthesis, and starch and sucrose metabolism were also significantly induced from T2. Key pivotal candidate genes were screened out. Our results provide fundamental resources for dissecting the molecular network regulating FBD and molecular-assisted flowering control in Michelia ‘Xin’. Full article

Spinach is a dioecious vegetable and an excellent model for investigating plant sex differentiation. Exogenous gibberellin treatment induced sepal hypoplasia and sex reversal, converting 42% of stamens into pistils in male plants. Transcriptome analysis identified 112 male-biased genes enriched in stamen and pollen development, while hormone profiling revealed coordinated changes in GA, cytokinins, auxin, jasmonic acid, and abscisic acid. Functional assays demonstrated that silencing SpAMS or SpPGIP caused extensive carpelization, and in situ hybridization localized their expression to developing anthers. Dual-luciferase assays confirmed that SpAMS directly activates the B-class gene SpPI, and genomic mapping placed SpAMS in the pseudo-autosomal region of the Y chromosome. These results indicate that GA disrupts hormonal homeostasis and anther wall integrity, while the SpAMS–SpPI pathway regulates tapetal development to maintain male identity. Our findings identify SpAMS as a key male-promoting factor in spinach and provide a framework for elucidating sex determination mechanisms in dioecious plants. Full article

Carbon (C), nitrogen (N) and phosphorus (P), and non-structural carbohydrates (NSCs) are basic nutrients and energy sources for flower development. In this study, the morphological traits, C, N, P, and NSC concentrations, and C:N:P ratios in pistil, stamen, and petal of C. maxima flower at three phenophases (BBCH54, BBCH59, and BBCH61) were comparatively analyzed. Morphology diverged markedly among the three phenophases, whereas relative water contents were stable. C, N, P, and NSC showed larger variations at three phenophases and parts in C. maxima flower. Maximal C:N, C:P, and N:P occurred in pistils, pistils, and petals at BBCH61, respectively. C:N:P stoichiometry was the most responsive to ontogeny, indicating development-specific elemental storage and biomass partitioning of C. maxima flowers. NSC contents (glucose, fructose, sucrose, starch) differed significantly among organs and phenophases, and peak NSC appeared in the pistils at the three phenophases. High correlations between NSCs and C:N:P ratios suggested coordinated resource allocation. Correlation analysis showed that significant differences occurred at three phenophases for the accumulation and allocation of C, N, P, and NSCs. Principal component analysis (PCA) ordinated samples along PC-1 (44.2%) and PC-2 (24.4%), cumulatively explaining 68.6% of variance, corroborating development- and organ-dependent divergence. These data elucidated the intricate regulatory dynamics of nutrient contents among the three parts during the flower development of C. maxima, providing a robust quantitative framework for targeted nutrient management strategies. Full article

Houpoea officinalis (H. officinalis) flowers are rich in a spectrum of bioactive compounds and mineral nutrients. The availability and balance of mineral elements directly impact the morphogenesis of flower organs, which play pivotal roles in various physiological and biochemical processes that drive flower development. However, relatively little is known about the changes in mineral elements composition that occur during flower development in H. officinalis. The objective of this study is to analyze the variations of 22 mineral elements contents in pistil, stamens, and petals of H. officinalis flower at four development stages. The amount of mineral elements (Na, Mg, K, Ca, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sr, Sn, Al, Ti, Ga, Cd, Ba, Tl, Pb, and Bi) in these samples was determined using atomic absorption spectroscopy and inductively coupled plasma mass spectrometry. Results showed that H. officinalis flowers are rich in macroelements such as potassium (K, 25.80–48.06 mg/g) and calcium (Ca, 17.27–31.00 mg/g), as well as microelements like zinc (Zn, 445.17–1553.16 μg/g) and iron (Fe, 324.27–622.31 μg/g). Notably, the pistil part is found to harbor a more significant concentration of mineral elements during the early developmental stages of flowers. Correlation analysis and PCA have effectively exposed a pronounced association between the accumulation patterns of mineral elements in H. officinalis flowers and their corresponding developmental stages and organs. These findings will provide more detailed information about the accumulation and distribution of mineral elements in H. officinalis flowers at different development stages and organs, which help to encourage researchers to enhance the flower quality for human consumption. Full article

Arabinogalactan proteins (AGPs) are complex proteoglycans present in plant cell walls across the kingdom. They play crucial roles in biological functions throughout the plant life cycle. In this study, we identified 43 gene members of the AG peptide (an AGP subfamily) within the rice genome, detailing their structure, protein-conserved domains, and motif compositions for the first time. We also examined the expression patterns of these genes across 18 tissues and organs, especially the different parts of the flower (anthers, pollen, pistil, sperm cells, and egg cells). Interestingly, the expression of some AG peptides is mainly present in the pollen grain. Transcription data and GUS staining confirmed that OsAGP6P—a member of the AG peptide gene family—is expressed in the stamen during pollen development stages 11–14, which are critical for maturation as microspores form after meiosis of pollen mother cells. It became noticeable from stage 11, when exine formation occurred—specifically at stage 12, when the intine began to develop. The overexpression of this gene in rice decreased the seed-setting rate (from 91.5% to 30.5%) and plant height (by 21.9%) but increased the tillering number (by 34.1%). These results indicate that AGP6P contributes to the development and fertility of pollen, making it a valuable gene target for future genetic manipulation of plant sterility through gene overexpression or editing. Full article

Flowers are one of the most important organs in plants. Their development serves as a key indicator of the transition from vegetative to reproductive growth and is regulated by various internal signals and environmental factors. NAC (NAM, ATAF, CUC) transcription factors (TFs) play a crucial regulatory role in floral organ development; however, research on the analysis and identification of the NAC TF family in Chinese cabbage (Brassica rapa L.) remains limited. In this study, we performed a comprehensive genome-wide analysis of NACs in B. rapa and identified 279 members of the BrNAC gene family. Their physicochemical properties, domain structure, collinearity relation, and cis-regulatory elements were evaluated. Phylogenetic analysis indicates that NAC proteins from Arabidopsis, B. rapa, B. oleracea, and B. nigra can be classified into seven distinct clades. BrNACs exhibit a tissue-specific expression, and nine BrNACs being specifically expressed in the inflorescence. Furthermore, nine flower-related BrNACs were selected for RT-qPCR analysis to validate their expression profiles. BrNAC2s has been cloned to investigate their subcellular localization, and examine the expression patterns of their promoters in Arabidopsis inflorescences. BrNAC2a and BrNAC2c are highly expressed in stamens while BrNAC2b exhibits elevated expression in pistils and pedicel. Collectively, our findings enhance the understanding of the BrNAC family and provide a foundation for future studies on the molecular mechanisms of BrNACs in floral development. Full article

Rose is one of the most popular ornamental plants worldwide. The double-flower trait, referring to flowers with extra petals, has been a key focus in rose breeding history. However, the genetic mechanisms regulating petal number in roses are still not fully understood. Here, we identified the CUP-SHAPED COTYLEDON 3 (RhCUC3) gene in the miniature rose (Rosa hybrida ‘Eclair’). The expression of RhCUC3 was high during the petal and stamen primordium differentiation stages but declined sharply during pistil primordium development. RhCUC3 belongs to the NAM/CUC3 subgroup of NAC transcription factors and is localized in the nucleus. The transcript level of RhCUC3 increased significantly with ABA and GA treatments and was inversely down-regulated with MeJA and 6-BA treatments. Silencing RhCUC3 using virus-induced gene silencing (VIGS) in rose ‘Eclair’ significantly decreased the number of petaloid stamens and normal petals while slightly increasing the number of stamens. Additionally, the expression of RhAG and RhAGL, two MADS-box genes associated with floral organ identity, was significantly higher in TRV-RhCUC3 compared to the TRV control. These findings suggest that RhCUC3 enhances stamen petaloidy and petal number, potentially by modulating the expression of RhAG and RhAGL, providing new insights into the function of NAC transcription factors in plants. Full article

Flowers, serving as the reproductive structures of angiosperms, perform an integral role in plant biology and are fundamental to understanding plant evolution and taxonomy. The growth and organogenesis of flowers are driven by numerous factors, such as external environmental conditions and internal physiological processes, resulting in diverse traits across species or even within the same species. Among these factors, genes play a central role, governing the entire developmental process. The regulation of floral genesis by these genes has become a significant focus of research. In the AE model of floral development, the five structural whorls (calyx, corolla, stamens, pistils, and ovules) are controlled by five groups of genes: A, B, C, D, and E. These genes interact to give rise to a complex control system that governs the floral organsgenesis. The activation or suppression of specific gene categories results in structural modifications to floral organs, with variations observed across different species. The present article examines the regulatory roles of key genes, including genes within the MADS-box and AP2/ERF gene clusters, such as AP1, AP2, AP3, AG, STK, SHP, SEP, PI, and AGL6, as well as other genes, like NAP, SPL, TGA, PAN, and WOX, in shaping floral organ genesis. In addition, it analyzes the molecular-level effects of these genes on floral organ formation. The findings offer a deeper understanding of the genetic governance of floral organ genesis across plant species. Full article

Flower morphology is a critical ornamental trait in flowering plants. Elucidating the molecular mechanisms underlying flower development is essential for the breeding of diverse ornamental plant cultivars. The ABCE model genes are pivotal in regulating floral development in angiosperms. In order to understand the molecular mechanism of flower development in Clematis, nine ABCE model genes were identified from the transcriptome data of Clematis cv. ‘Amethyst Beauty’. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis revealed tissue-specific expression patterns among these genes. ClPI, ClSEP1, and ClSEP3 were predominantly expressed in sepals. ClAP3, ClPI, ClAG2, ClSEP1, and ClSEP3 were highly expressed in stamens. ClAG1 was exclusively expressed in pistils. These findings suggested that ABCE genes may play an important role in regulating the formation of flower morphology in the Clematis. The open reading frame (ORF) of ClAG2 was cloned and overexpression of ClAG2 in tobacco resulted in shorter corolla tube, reduced crown area, and stunted stamen. ClAG2 may have a negative effect on the formation of double-tepal flowers of Clematis and play a specific role in stamen and pistil development. Yeast two-hybrid assays demonstrated that ClAG2 could interact with class E proteins ClSEP3 and ClSEP4 but not with class B proteins ClAP3 and ClPI. Our results will lay a theoretical foundation for further research on the mechanism of flower development regulation in Clematis. Full article

Stamens are vital reproductive organs in angiosperms, essential for plant growth, reproduction, and development. The genetic regulation and molecular mechanisms underlying stamen development are, however, complex and varied among different plant species. MSL-lncRNAs, a gene specific to the Y chromosome of Populus deltoides, is predominantly expressed in male flower buds. Heterologous expression of MSL-lncRNAs in Arabidopsis thaliana resulted in an increase in both stamen and anther count, without affecting pistil development or seed set. To reveal the molecular regulatory network influenced by MSL-lncRNAs on stamen development, we conducted transcriptome sequencing of flowers from both wild-type and MSL-lncRNAs-overexpressing Arabidopsis. A total of 678 differentially expressed genes were identified between wild-type and transgenic Arabidopsis. Among these, 20 were classified as transcription factors, suggesting a role for these regulatory proteins in stamen development. GO enrichment analysis revealed that the differentially expressed genes were significantly associated with processes such as pollen formation, polysaccharide catabolic processes, and secondary metabolism. KEGG pathway analysis indicated that MSL-lncRNAs might promote stamen development by upregulating genes involved in the phenylpropanoid biosynthesis pathway. The top three upregulated genes, all featuring the DUF295 domain, were found to harbor an F-box motif at their N-termini, which is implicated in stamen development. Additionally, in transgenic Arabidopsis flowers, genes implicated in tapetum formation and anther development were also observed to be upregulated, implying a potential role for MSL-lncRNAs in modulating pollen development through the positive regulation of these genes. The findings from this study establish a theoretical framework for elucidating the genetic control exerted by MSL-lncRNAs over stamen and pollen development. Full article

Arabidopsis AGAMOUS (AG) plays a crucial role in specifying stamen and carpel identities, floral meristem identity determination, and repression of the A-function. Ilex verticillata (Aquifoliaceae) is a dioecious shrub, whereby an individual plant has either male or female flowers with vestigial organs of the opposite sex. The molecular mechanism of male and female organ development in I. verticillata remains unknown. In order to identify the possible roles of AG-like genes in regulating floral development in I. verticillata, AG ortholog (IlveAG) and its promoter (pIlveAG) from the male and female flowers of I. verticillata were separately isolated. IlveAG is highly expressed in stamens, pistils, and sepals of male and female flowers. Moreover, obvious GUS staining was observed in the inflorescence and sepals, stamens, and pistils of mature flowers in pIlveAG::GUS Arabidopsis. The 35S::IlveAG Arabidopsis showed obviously early flowering. Moreover, IlveAG could substitute for endogenous AG to rescue the stamen and pistil in the Arabidopsis ag-1 mutant. In addition, expression of IlveAG can inhibit the development of sepals and petals (two outer whorls of floral organs) in wild-type and ag-1 Arabidopsis. Our findings suggest that IlveAG has a conservative C-function and plays key roles in determination of reproductive floral organs (stamen and carpel) identity and meristem determinacy. Our results provide more details to understand the role of AG orthologs in the development of male and female flowers in woody plants. Full article