Search Results (19)

Jasmonate ZIM-domain (JAZ) proteins play a pivotal role in mediating plant growth, development, and responses to both biotic and abiotic stresses. However, our knowledge about the JAZ family genes in Areca catechu remains limited. This study conducted a genome-wide screening and analysis of JAZ genes in A. catechu to investigate their biochemical characteristics, gene structure features, phylogenetic relationships, and expression profiles in different organs. A total of 14 JAZ genes (AcJAZs) were detected in the A. catechu genome, all containing an N-terminal TIFY domain and a C-terminal Jas domain. Phylogenetic analysis categorized these AcJAZs into five subfamilies according to their similarities in protein sequences. Quantitative real-time reverse transcription PCR (qRT-PCR) experiments demonstrated the ample expression specificity of these AcJAZ genes across different organs and flower development stages. More importantly, most AcJAZ genes are expressed significantly higher in blooming male flowers than female flowers, suggesting that they may participate in regulating the difference between male and female flowers of A. catechu. This study elucidates the genomic features and functions of JAZ genes in A. catechu, providing new insights into the mechanisms underlying the development and differentiation of unisexual flowers in A. catechu. Full article

The Lauraceae family, a keystone group in subtropical evergreen broad-leaved forest ecosystems, exhibits exceptional diversity in sexual systems (including hermaphroditic flowers, functionally unisexual flowers, and pseudo-dioecy), serving as a natural model for studying plant sexual differentiation mechanisms. This review synthesizes advances in the evolutionary mechanisms and genomic studies of sexual differentiation in Lauraceae, focusing on three key areas: (1) the evolution of taxonomic classification and floral morphology, (2) molecular trajectories of sexual differentiation, and (3) challenges and future directions in sex determination research (e.g., sex-linked marker development and gene-editing-assisted breeding). Morphological and phylogenetic analyses suggest that ancestral Lauraceae species were late Cretaceous hermaphroditic trees, with recent radiation of unisexual lineages (e.g., Cinnamomum and Laurus) linked to pollinator pressure, genome duplication events (WGD), and incipient sex chromosome evolution. Despite progress, critical challenges remain, including unresolved thresholds for sex chromosome origination, unquantified molecular pathways integrating environmental signals (e.g., photoperiod, temperature) with genetic networks, and the lack of efficient sex-specific markers and genetic transformation systems. Future studies should integrate single-cell omics, epigenetic profiling, and cross-species comparative genomics to elucidate spatiotemporal dynamics and evolutionary drivers of sexual differentiation. These efforts will advance genetic improvement and ecological restoration strategies. This review provides a systematic framework for advancing plant sexual evolution theory and promoting sustainable utilization of Lauraceae resources. Full article

Despite extensive research on orchid reproductive strategies, the genetic studies of sex differentiation in the orchid family are still lacking. In this study, we compared three sexual phenotypes of Cymbidium tortisepalum bisexual flowers as well as female and male unisexual mutants. Through comparative transcriptomes, we analyzed the sex-biased differentially expressed genes (DEGs) and gene co-expression networks of sex organs (gynostemium and ovary) among them, identified the candidate genes of sex differentiation, and validated their expression by qRT-PCR. The C. tortisepalum unisexual mutants with degenerated phenotypes were compared to the bisexual plants with respect to both the flower organs and plant morphologies. Totally, 12,145, 10,789, and 14,447 genes were uniquely expressed in the female, male, and hermaphrodite sex organs, respectively. A total of 4291 sex-biased DEGs were detected among them, with 871, 2867, and 1937 DEGs in the comparisons of bisexual vs. female, bisexual vs. male, and male vs. female flowers, respectively. Two co-expressed network modules, with 81 and 419 genes were tightly correlated with female sexual traits, while two others with 265 and 135 genes were highly correlated with male sexual traits. Two female-biased hub genes (CtSDR3b and CtSDR3b-like) nested in the female modules, the homologs of maize sex determinant tasselseed2, may control the feminization of C. tortisepalum. At the same time, two male-biased hub genes (CtYAB2 and CtYAB5) nested in the male modules, the homologs of grape sex determinant VviYABBY3, may control the androphany of C. tortisepalum. This study discovered the molecular regulation networks and proposed a model for orchid sex differentiation, therefore providing for the first time the genetic basis for the sex separation in the orchid family. Full article

Cannabis sativa L. is cultivated globally for its cannabinoid-dense inflorescences. Commercial preference for sinsemilla has led to the development of methods for producing feminized seeds through cross-pollination of cosexual (masculinized) female plants. Although the induction of cosexuality in Cannabis plants is common, to date, no work has empirically tested how masculinization of female Cannabis plants impacts male flowering, pollen production, pollen fitness, and related life-history trade-offs. Here, we cultivated a population of Cannabis plants (CFX-2) and explored how the route to cosexuality (drought vs. chemical induction) impacted flowering phenology, pollen production, and pollen fitness, relative to unsexual male plants. Unisexual males flowered earlier and longer than cosexual plants and produced 223% more total pollen (F_2,28 = 74.41, p < 0.001), but per-flower pollen production did not differ across reproductive phenotypes (F_2,21 = 0.887, p = 0.427). Pollen viability was 200% higher in unisexual males and drought-induced cosexuals (F_2,36 = 189.70, p < 0.001). Pollen non-abortion rates only differed in a marginally significant way across reproductive phenotypes (F_2,36 = 3.00, p = 0.06). Here, we demonstrate that masculinization of female plants impacts whole-plant pollen production and pollen fitness in Cannabis sativa. Full article

Ribes L. belongs to the Grossulariaceae family and has important edible, medicinal, ornamental, and landscaping values. Taxonomic classification within this genus is difficult due to its large variety of species, wide distribution, large morphological variations, and presence of two complex taxonomic groups with bisexual or unisexual flowers. Our study aims to clarify the phylogenetic relationships of Ribes L. taxa in China, and further, to provide a reference for a revised global classification of it. The phylogenetic analysis of 52 Ribes L. samples from 30 species was constructed based on restriction site-associated DNA sequencing and single nucleotide polymorphisms. Afterward, two important taxonomic characters were selected for ancestral state reconstruction over the molecular phylogeny. The results showed that the 52 samples could be divided into six branches, i.e., six subgenera, which caused some controversy regarding the morphological classification of Ribes L. in China. The molecular phylogeny supported the separation of subg. Coreosma from subg. Ribesia and subg. Hemibotrya from subg. Berisia and validated the rationale for recognizing subg. Grossularia as an independent subgenus, the rationality of which was further verified by the reconstruction of ancestor traits. Gene flow among Ribes L. was identified and further confirmed our results. Full article

Catasetum is a speciose Neotropical orchid genus of which male and female flowers emit scents acting both as attractant and reward for their exclusive pollinators, male orchid bees (Euglossini: Apidae). In Catasetum, it is well known that flowers display a remarkably morphological sexual dimorphism. However, it remains poorly investigated whether this is also true for floral scents. Here, we investigated the pollination ecology and floral scent traits (chemistry and total emission) of C. maranhense, a species endemic to the Brazilian N/NE region. Males of Euglossa securigera are the only pollinators of C. maranhense. The floral scent of C. maranhense is composed of 29 volatile compounds, with eucalyptol, indole, (E)-Methyl p-methoxycinnamate, and (Z)-Methyl p-methoxycinnamate accounting for more than 80% of the scent bouquet. No sexual dimorphism was detected in any of the traits investigated. We discuss the ecological and evolutionary significance of our findings to Catasetum species and other unisexual perfume plants. Full article

Transcription factors are crucial for plant growth and development. MADS-box, WRKY, NAC, and SBP-box, some of the most vital transcription factors, are not well identified in Diospyros spp., and their floral development and sex differentiation related functions remain unknown. We identified and analysed 53 MADS-box, 66 WRKY, 83 NAC, and 17 SBP-box transcription factors using the chromosomal D. oleifera genome. There were six DolSBPs identified as miR156 and miR157 targets. According to the multiple sequence alignments of Arabidopsis and D. oleifera proteins and their conserved domains and motifs, DolMADSs were divided into 23 type I and 30 type II. The DolWRKYs, DolNACs, and DolSBPs were divided into 7, 16, and 6 subgroups, respectively. It was found that one DolMADS, five DolWRKYs, one DolNAC, and four DolSBPs may promote unisexual female flowers development, while three DolMADSs, four DolWRKYs, and one DolNAC may enhance unisexual male flowers development. The functions among the different members of the same family may, thus, vary widely. The results will help to elucidate the evolution of the MADS-box, WRKY, NAC, and SBP-box genes families in D. oleifera and to determine their functions in flower development for Diospyros spp. Full article

S. chinensis is a typical monoecious plant, and the number and development of female flowers determines the yield of S. chinensis. Due to a lack of genetic information, the molecular mechanism of sex differentiation in S. chinensis remains unclear. In this study, the combination of scanning electron microscopy (SEM) and RNA sequencing (RNA-seq) was used to understand the way of sex differentiation of S. chinensis and to mine the related genes of sex determination. The result shows the development of male and female S. chinensis flowers was completed at the same time, the unisexual S. chinensis flowers did not undergo a transition stage between sexes, and sex may have been determined at an early stage in flower development. The results of the gene function analysis of the plant hormone signaling pathway and sucrose metabolism pathway suggest that auxin and JA could be the key hormones for sex differentiation in S. chinensis, and sucrose may promote pollen maturation at the later stage of male flower development. Two AGAMOUS (GAG) genes, 10 AGAMOUS-like MADS-box (AGLs) genes, and the MYB, NAC, WRKY, bHLH, and Trihelix transcription factor families may play important roles in sex determination in S. chinensis. Taken together, the present findings provide valuable genetic information on flower development and sex determination in S. chinensis. Full article

Sex determination and differentiation is an important biological process for unisexual flower development. Spinach is a model plant to study the mechanism of sex determination and differentiation of dioecious plant. Till now, little is known about spinach sex determination and differentiation mechanism. MicroRNAs are key factors in flower development. Herein, small RNA sequencing was performed to explore the roles of microRNAs in spinach sex determination and differentiation. As a result, 92 known and 3402 novel microRNAs were identified in 18 spinach female and male flower samples. 74 differentially expressed microRNAs were identified between female and male flowers, including 20 female-biased and 48 male-biased expression microRNAs. Target prediction identified 22 sex-biased microRNA-target pairs, which may be involved in spinach sex determination or differentiation. Among the differentially expressed microRNAs between FNS and M03, 55 microRNAs were found to reside in sex chromosome; one of them, sol-miR2550n, was functionally studied via genetic transformation. Silencing of sol-miR2550n resulted in abnormal anther while overexpression of sol-miR2550n induced early flowering, indicating sol-miR2550n was a male-promoting factor and validating the reliability of our small RNA sequencing data. Conclusively, this work can supply valuable information for exploring spinach sex determination and differentiation and provide a new insight in studying unisexual flower development. Full article

In this study, distyly was clearly confirmed in Polygonum criopolitanum Hance, which exhibited strict self-incompatibility. Unlike other distylous species, style-morph ratios of P. criopolitanum often deviated obviously from 1:1, and many populations were solely composed of long or short stylous flowers; the 1:1 style-morph ratio was occasionally found in very large populations. P. criopolitanum was dimorphic for intrinsic features such as style height and anther height and ancillary features such as pollen size and number. The L-morph flowers produced a significantly smaller and higher number of pollen grains than the S-morph flowers, and the stigma papillae of both morphs were not significantly different. We nearly found no seed sets in most wild populations and very low seed sets occasionally occurred in large populations, which was different from other species of Polygonaceae. Mating experiments showed that P. criopolitanum has a strict self-incompatibility system and clonal propagation was more common than sexual propagation, which was adaptive with the unisexual wild populations. Hygrocolous habitat, 20–60% soil water content, and height gap less than 4 m to the adjacent water were the main limiting factors for the distribution of P. criopolitanum. Full article

Salix is a dioecious plant. Research on the molecular regulation mechanism of male and female inflorescence differentiation and development is necessary to analyze sex differentiation in the willow and the underlying mechanisms of unisexual flower development. However, at present, there are no reference genes suitable for stable expression in the process of willow inflorescence development. In this study, Salix suchowensis was used as the research material, nine candidate reference genes (α-TUB1, α-TUB2, ACT, H2A, DnaJ, CDC2, GAPDH, TIP41, β-TUB) were selected, and qRT-PCR technology was used to detect the expression of each candidate reference gene in female and male flowers at different developmental stages and using five algorithms (geNorm, Normfinder, Delta Ct, BestKeeper, and RefFinder) to comprehensively evaluate the stability of candidate reference genes. The results showed that ACT and DnaJ were stably expressed in all samples and could be used as reference genes. In addition, the reliability of the screening results was further verified via an expression pattern analysis of the CFS gene that encodes flower specific transcription factor in different samples. The stable reference genes selected in this study provide the basis for future research on the expression analysis of functional genes related to the development of male and female flowers of S. suchowensis. Full article

The development of unisexual flowers has been described in a large number of taxa, sampling the diversity of floral phenotypes and sexual systems observed in extant angiosperms, in studies focusing on floral ontogeny, on the evo-devo of unisexuality, or on the genetic and chromosomal bases of unisexuality. We review here such developmental studies, aiming at characterizing the diversity of ontogenic pathways leading to functionally unisexual flowers. In addition, we present for the first time and in a two-dimensional morphospace a quantitative description of the developmental rate of the sexual organs in functionally unisexual flowers, in a non-exhaustive sampling of angiosperms with contrasted floral morphologies. Eventually, recommendations are provided to help plant evo-devo researchers and botanists addressing macroevolutionary and ecological issues to more precisely select the taxa, the biological material, or the developmental stages to be investigated. Full article

Handeliodendron bodinieri has unisexual flowers with aborted stamens in female trees, which can be used to study unisexual flower development in tree species. To elucidate the molecular mechanism of stamen abortion underlying sex differentiation, the stage of stamen abortion was determined by semi-thin sections; results showed that stamen abortion occurred in stage 6 during anther development. In addition, differentially expressed transcripts regulating stamen abortion were identified by comparing the transcriptome of female flowers and male flowers with RNA-seq technique. The results showed that 14 genes related to anther development and meiosis such as HbGPAT, HbAMS, HbLAP5, HbLAP3, and HbTES were down-regulated, and HbML5 was up-regulated. Therefore, this information will provide a theoretical foundation for the conservation, breeding, scientific research, and application of Handeliodendron bodinieri. Full article

The sweet chestnut tree (Castanea sativa Mill.) is one of the most significant Mediterranean tree species, being an important natural resource for the wood and fruit industries. It is a monoecious species, presenting unisexual male catkins and bisexual catkins, with the latter having distinct male and female flowers. Despite the importance of the sweet chestnut tree, little is known regarding the molecular mechanisms involved in the determination of sexual organ identity. Thus, the study of how the different flowers of C. sativa develop is fundamental to understand the reproductive success of this species and the impact of flower phenology on its productivity. In this study, a C. sativa de novo transcriptome was assembled and the homologous genes to those of the ABCDE model for floral organ identity were identified. Expression analysis showed that the C. sativa B- and C-class genes are differentially expressed in the male flowers and female flowers. Yeast two-hybrid analysis also suggested that changes in the canonical ABCDE protein–protein interactions may underlie the mechanisms necessary to the development of separate male and female flowers, as reported for the monoecious Fagaceae Quercus suber. The results here depicted constitute a step towards the understanding of the molecular mechanisms involved in unisexual flower development in C. sativa, also suggesting that the ABCDE model for flower organ identity may be molecularly conserved in the predominantly monoecious Fagaceae family. Full article

Persimmon (Diospyros kaki Thunb) species is a hexaploid genotype that has a morphologically polygamous gyonodioecious sexual system. D. kaki bears unisexual flowers. The presence of male flowers resulted in the presence of seeds in the varieties. The fruits of persimmon are classified according to their astringency and the pollination events that produced seeds and modify the levels of astringency in the fruit. The presence of seeds in astringent varieties as pollination variant astringent (PVA), pollination variant non-astringent (PVNA) and pollination constant astringent (PCA) resulted in fruits not marketable. Molecular markers that allow selection of the varieties according to the type of flowers at the plantlet stage would allow selection of seedless varieties. In this study, a marker developed in D. lotus by bulk segregant analysis (BSA) and amplified fragment length polymorphism (AFLP) markers, named DlSx-AF4, has been validated in a germplasm collection of persimmon, results obtained agree with the phenotype data. A second important trait in persimmon is the presence of astringency in ripened fruits. Fruits non-astringent at the ripen stage named pollination constant non-astringent (PCNA) are the objective of many breeding programs as they do not need removal of the astringency by a postharvest treatment. Astringency in the hexaploid persimmon is a dominant trait. The presence of at least one astringent allele confers astringency to the fruit. In this paper we checked the marker developed linked to the AST gene. Our goal has been to validate both markers in germplasm from different origins and to test the usefulness in a breeding program. Full article