Project description:Fertile pollen is critical for the survival, fitness and dispersal of flowering plants, and directly contributes to crop productivity. Extensive mutational screening studies have been carried out to dissect the genetic regulatory network determining pollen fertility, but we still lack fundamental knowledge about whether and how pollen fertility is controlled in natural populations. We used a genome-wide association study (GWAS) to show that ZmGEN1A and ZmMSH7, two DNA repair-related genes, confer natural variation in maize pollen fertility. Mutants defective in both genes exhibited abnormalities in meiotic or post-meiotic DNA repair, leading to reduced pollen fertility. More importantly, ZmMSH7 underwent selection during maize domestication, and its disruption resulted in a substantial increase in grain yield and protein content for both inbred and hybrid. Overall, our study describes the first systematic examination of natural genetic effects on pollen fertility in plants, providing valuable genetic resources for optimizing male fertility. Moreover, ZmMSH7 may be a potential candidate for simultaneous improvement of grain yield and quality.
Project description:Formation of functional pollen and successful fertilisation relies upon the spatial and temporal regulation of anther and pollen development. This process responds to environmental cues to maintain optimal fertility despite climatic changes. Arabidopsis transcription factors bHLH10,-89,-91 were previously thought to be functionally redundant in their control of male reproductive development, however here we show that they play distinct roles in the integration of light signals to maintain pollen development under different environmental conditions. Combinations of the double and triple bHLH10,-89,-91 mutants were analysed under normal (200μmol/m2/s) and low (50μmol/m2/s) light conditions to determine the impact on fertility. Transcriptomic analysis of a new conditionally sterile bhlh89,91 double mutant shows differential regulation of genes related to sexual reproduction, hormone signal transduction and lipid storage and metabolism under low-light. Here we have shown that bHLH89 and bHLH91 play a role in regulating fertility in response to light, suggesting they function in mitigating environmental variation to ensure fertility is maintained under environmental stress.
Project description:Oryza longistaminata is an African wild rice species that possesses special traits for breeding applications. Self-incompatibility is the main cause of sterility in O. longistaminata, but here we demonstrated that its pollen fertility and vitality are normal. Lipid and carbohydrate metabolism were active throughout pollen development. In this study, transcriptomics quantitative analysis was used to investigate the profiles of genes related to lipid and carbohydrate metabolism in 4-, 6- and 8.5-mm O. longistaminata spikelets before flowering. We documented cytological changes throughout important stages of anther development, including changes in reproductive cells as they formed mature pollen grains through meiosis and mitosis. RNA-seq and proteome association analysis indicated that fatty acids were converted to sucrose after the 6-mm spikelet stage, based on the abundance of most key enzymes of the glyoxylate cycle and gluconeogenesis. In conclusion, our study provides novel insights into the pollen viability of O. longistaminata at the transcriptome level, which can be used to improve the efficiency of male parent pollination in hybrid rice breeding applications.
Project description:Illumina sequencing was employed to examine the expression profiles of rice anther miRNAs from the a non-pollen male sterile line Wuxiang S (WXS), one of photo-thermo sensitive genical male sterile (PTGMS) line rice, during in the fertility transition stage. A total of 493 known miRNAs and 273 novel miRNAs were identified during rice anther development. Based on the number of sequencing reads, a total of 26 miRNAs were discovered to be significant difference expression between WXS(S, Sterility) and WXS(F, Fertility), and the results were partially validated by qRT-PCR. Among these, 11 miRNAs were decreased and 15 miRNAs were increased in WXS(S) compared with WXS(F). The expression patterns for targets of osa-miR156a-j, osa-miR3879, osa-miR159c/d/e, osa-miR171a/c/e/i, osa-miR398b, osa-miR164d, osa-miR528 and osa-miR408 were selectively examined, and the results showed that there was a negative correlation on the expression patterns between miRNAs and their targets. These targets have previously been reported to be related with pollen development and male sterility, suggesting that miRNAs might act as regulators of rice anthers. Furthermore, miRNA editing events were observed. The U-to-C and U-to-A editing phenomenon was validated by molecular cloning and sequencing. Examine small RNA profiles change of four tissues of the rice non-pollen male sterile line Wuxiang S under two different environments.
Project description:Background: Partial pollen and embryo sac sterilities are the two main reasons for low fertility in autotetraploid rice. Our previous study revealed that small RNAs changes may associate with pollen fertility in autotetraploid rice. However, knowledge on comparative analysis between the development of pollen and embryo sac by small RNAs in autotetraploid rice is still unknown. In the present study, WE-CLSM (whole-mount eosin B-staining confocal laser scanning microscopy) and high-throughput sequencing technology was employed to examine the cytological variations and to analyze small RNAs changes during pollen and embryo sac development in autotetraploid rice compared with its diploid counterpart. Results: A total of 321 and 368 differentially expressed miRNAs (DEM) were detected during development of pollen and embryo sac in autotetraploid rice, respectively. Gene Ontology enrichment analysis on the targets of miRNAs-enriched during the development of pollen and embryo sac in autotetraploid rice revealed 30 prominent functional gene classes, such as cell differentiation and signal transduction during embryo sac development. However, only 7 prominent functional gene classes, such as flower development and transcription factor activity, were detected during pollen development. The expression levels of 39 DEM, which revealed interaction with meiosis-related genes, showed opposite expression levels in pollen and embryo sac development. Of these DEM, osa-miR1436_L+3_1ss5CT and osa-miR167h-3p were associated with the female meiosis, while osa-miR159a.1 and osa-MIR159a-p5 were related with the male meiosis. 21nt-phasiRNAs were detected both during pollen and embryo sac development, while 24nt-phasiRNAs were found only in pollen development, which displayed down-regulation in autotetraploid compared to diploid rice and their spatial-temporal expression patterns were similar to osa-miR2275d. 24nt TEs-siRNAs were found to be up-regulated in embryo sac but down-regulated in pollen development. Conclusion: The above results not only provide the small RNAs changes during four landmark stages of pollen and embryo sac development in autotetraploid rice but also have identified specifically expressed miRNAs, especially meiosis-related miRNAs, pollen-24nt-phasiRNAs and TEs-siRNAs in autotetraploid rice. Together, these findings provide a foundation for understanding the effect of polyploidy on small RNAs expression patterns during pollen and embryo sac development that may lead to different abnormalities in autotetraploid rice.
Project description:Illumina sequencing was employed to examine the expression profiles of rice anther miRNAs from the a non-pollen male sterile line Wuxiang S (WXS), one of photo-thermo sensitive genical male sterile (PTGMS) line rice, during in the fertility transition stage. A total of 493 known miRNAs and 273 novel miRNAs were identified during rice anther development. Based on the number of sequencing reads, a total of 26 miRNAs were discovered to be significant difference expression between WXS(S, Sterility) and WXS(F, Fertility), and the results were partially validated by qRT-PCR. Among these, 11 miRNAs were decreased and 15 miRNAs were increased in WXS(S) compared with WXS(F). The expression patterns for targets of osa-miR156a-j, osa-miR3879, osa-miR159c/d/e, osa-miR171a/c/e/i, osa-miR398b, osa-miR164d, osa-miR528 and osa-miR408 were selectively examined, and the results showed that there was a negative correlation on the expression patterns between miRNAs and their targets. These targets have previously been reported to be related with pollen development and male sterility, suggesting that miRNAs might act as regulators of rice anthers. Furthermore, miRNA editing events were observed. The U-to-C and U-to-A editing phenomenon was validated by molecular cloning and sequencing.
Project description:Cucumber is an important vegetable crop worldwide, which is mainly propagated by seed. The successful occurrence of double fertilization is the premise of seed production in angiosperms. Cucumber ALC homolog (CsALC) displayed a novel and positive function in pollen tube emergence process, and regulated female fertility by promoting CsRALF4/19 function during pollen tube guidance in cucumber.