RESULTS: In this study, we characterized a recessive genic male sterile mutant (366-2 S), where the delayed degradation of tapetum and the failure of tetrad separation primarily led to the inability to form single microspores, resulting in male sterility. To analyze the role of lncRNAs in pollen development, we conducted a comparative lncRNA sequencing using anthers from the male sterile mutant line (366-2 S) and the wild-type male fertile line (366-2 F). We identified 385 differentially expressed lncRNAs between the 366-2 F and 366-2 S lines, with 172 of them potentially associated with target genes. To further understand the alterations in mRNA expression and explore potential lncRNA-target genes (mRNAs), we performed comparative mRNA transcriptome analysis in the anthers of 366-2 S and 366-2 F at two stages. We identified 1,176 differentially expressed mRNAs. Remarkably, GO analysis revealed significant enrichment in five GO terms, most notably involving mRNAs annotated as pectinesterase and polygalacturonase, which play roles in cell wall degradation. The considerable downregulation of these genes might contribute to the delayed degradation of tapetum in 366-2 S. Furthermore, we identified 15 lncRNA-mRNA modules through Venn diagram analysis. Among them, MSTRG.9997-BraA04g004630.3 C (β-1,3-glucanase) is associated with callose degradation and tetrad separation. Additionally, MSTRG.5212-BraA02g040020.3 C (pectinesterase) and MSTRG.13,532-BraA05g030320.3 C (pectinesterase) are associated with cell wall degradation of the tapetum, indicating that these three candidate lncRNA-mRNA modules potentially regulate pollen development.
CONCLUSIONS: This study lays the foundation for understanding the roles of lncRNAs in pollen development and for elucidating their molecular mechanisms in regulating male sterility in Chinese cabbage.
结果:在这项研究中,我们表征了一个隐性基因雄性不育突变体(366-2S),其中绒毡层的延迟降解和四分体分离的失败主要导致无法形成单个小孢子,导致男性不育。分析lncRNAs在花粉发育中的作用,我们使用来自雄性不育突变系(366-2S)和野生型雄性可育系(366-2F)的花药进行了lncRNA比较测序.我们在366-2F和366-2S系之间鉴定了385种差异表达的lncRNAs,其中172个可能与靶基因有关。为了进一步了解mRNA表达的变化并探索潜在的lncRNA靶基因(mRNA),我们在366-2S和366-2F的花药中进行了两个阶段的比较mRNA转录组分析。我们鉴定了1,176个差异表达的mRNA。值得注意的是,GO分析显示五个GO术语显著富集,最值得注意的是涉及被注释为果胶酯酶和多聚半乳糖醛酸酶的mRNA,在细胞壁降解中起作用。这些基因的显著下调可能有助于366-2S中绒毡层的延迟降解。我们通过维恩图分析鉴定了15个lncRNA-mRNA模块。其中,MSTRG.9997-BraA04g004630.3C(β-1,3-葡聚糖酶)与call糖降解和四分体分离有关。此外,MSTRG.5212-BraA02g040020.3C(果胶酯酶)和MSTRG.13,532-BraA05g030320.3C(果胶酯酶)与绒毡层的细胞壁降解有关,表明这三个候选lncRNA-mRNA模块可能调节花粉发育。
结论:本研究为了解lncRNAs在大白菜花粉发育中的作用及其调控雄性不育的分子机制奠定了基础。