Nie Hushuai, Wang Yumei, Su Ying, Hua Jinping
Laboratory of Cotton Genetics, Genomics and Breeding/Beijing Key Laboratory of Crop Genetic Improvement/Key Laboratory of Crop Heterosis and Utilization of Ministry of Education, College of Agronomy and Biotechnology, China Agricultural University, Beijing, 100193, China.
Research Institute of Cash Crops, Hubei Academy of Agricultural Sciences, Wuhan, 430064, Hubei, China.
Funct Integr Genomics. 2018 Jul;18(4):457-476. doi: 10.1007/s10142-018-0606-z. Epub 2018 Apr 7.
Cytoplasmic male sterility (CMS) lines provide crucial material to harness heterosis for crop plants, which serves as an important strategy for hybrid seed production. However, the molecular mechanism remains obscure. Although microRNAs (miRNAs) play important roles in vegetative growth and reproductive growth, there are few reports on miRNAs regulating the development of male sterility in Upland cotton. In present study, 12 small RNA libraries were constructed and sequenced for two development stages of flower buds from a CMS line and its maintainer line. Based on the results, 256 novel miRNAs were allocated to 141 new miRNA families, and 77 known miRNAs belonging to 54 conserved miRNA families were identified as well. Comparative analysis revealed that 61 novel and 10 conserved miRNAs were differentially expressed. Further transcriptome analysis identified 232 target genes for these miRNAs, which participated in cellular developmental process, cell death, pollen germination, and sexual reproduction. In addition, expression patterns of typical miRNA and the negatively regulated target genes, such as PPR, ARF, AP2, and AFB, were verified by qRT-PCR in cotton flower buds. These targets were previously reported to be related to reproduction development and male sterility, suggesting that miRNAs might act as regulators of CMS occurrence. Some miRNAs displayed specific expression profiles in special developmental stages of CMS line and its fertile hybrid (F). Present study offers new information on miRNAs and their related target genes in exploiting CMS mechanism, and revealing the miRNA regulatory networks in Upland cotton.
细胞质雄性不育（CMS）系为作物利用杂种优势提供了关键材料，这是杂交种子生产的一项重要策略。然而，其分子机制仍不清楚。尽管微小RNA（miRNA）在营养生长和生殖生长中发挥着重要作用，但关于miRNA调控陆地棉雄性不育发育的报道却很少。在本研究中，构建了12个小RNA文库，并对一个CMS系及其保持系花蕾的两个发育阶段进行了测序。基于这些结果，256个新的miRNA被归入141个新的miRNA家族，同时还鉴定出了属于54个保守miRNA家族的77个已知miRNA。比较分析表明，有61个新的miRNA和10个保守miRNA差异表达。进一步的转录组分析确定了这些miRNA的232个靶基因，它们参与细胞发育过程、细胞死亡、花粉萌发和有性生殖。此外，通过qRT-PCR验证了棉花花蕾中典型miRNA及其负调控靶基因（如PPR、ARF、AP2和AFB）的表达模式。这些靶基因先前被报道与生殖发育和雄性不育有关，表明miRNA可能作为CMS发生的调节因子。一些miRNA在CMS系及其可育杂种（F）的特殊发育阶段表现出特定的表达谱。本研究为利用CMS机制以及揭示陆地棉中的miRNA调控网络提供了有关miRNA及其相关靶基因的新信息。
