Transcriptome analysis implicates involvement of long noncoding RNAs in cytoplasmic male sterility and fertility restoration in cotton

Abstract Background Hybrid cotton has greatly contributed to global increase in cotton productivity. The cytoplasmic male sterility (CMS)/restorer-of-fertility system is an important tool to exploit heterosis because it is convenient for commercial hybrid seed production. The importance of long noncoding RNAs (lncRNAs) in plant development is recognized, few analyses of lncRNAs during anther development of three-line hybrid cotton (CMS-D2 line A, maintainer line B, restorer-of-fertility line R) have been reported. Results Here, we performed transcriptome sequencing during anther development in Upland cotton carrying cytoplasmic male sterile Gossypium harknessii (D2) cytoplasm. Totally 80,695 lncRNAs were identified, in which 43,347 and 44,739 lncRNAs were differentially expressed in A–B and A–R comparisons, respectively. These lncRNAs represent functional candidates involved in CMS and fertility restoration. Gene ontology enrichment analysis indicated that cellular hormone metabolic processes and oxidation–reduction reaction processes might be involved in CMS, and cellular component morphogenesis and small molecular biosynthetic processes might participate in fertility restoration. Analysis of the putative relationship between lncRNAs and miRNAs revealed that 63 lncRNAs were identified as putative precursors of 35 miRNAs, and qRT-PCR analysis showed a similar expression pattern to that of RNA-sequencing data. Furthermore, construction of lncRNA regulatory networks indicated that several miRNA–lncRNA–mRNA networks might be involved in CMS and fertility restoration. Conclusion Our findings provide systematic identification of lncRNAs during anther development and lays a solid foundation for future investigation of the regulatory molecular mechanisms and utilization in ­­breeding of hybrid cotton.