Identification of AtSND1 homologous NAC genes related to cotton fiber development, in silico analyses, and gene expression patterns

Abstract

Abstract Because cotton is the most important fiber crop, the differentiation and development mechanism of cotton fiber cells has been a hot topic in cotton research. NAC (for NAM, ATAF, and CUC2) is a class of plant‐specific transcription factor families that regulate multiple aspects of plant growth and development. Previously, we identified 33 differentially expressed NAC genes in upland cotton based on fiber‐related transcriptome profiling. In this study, we conducted chromosome localization, systematic evolution, and gene structural analysis of 242 NAC genes genome‐wide based on a high‐quality reference genome of upland cotton. In addition, the expression pattern analysis of 16 differentially expressed GhNACs was carried out by RT–PCR using ovules at early fiber initiation stages of n2 recessive naked seed mutant (n2NSM) and Xuzhou142 fuzzless–lintless mutant (Xu142fl). The results showed that GhNAC230 and GhNAC115 were most closely related to AtSND1 and downregulated in ovules of Xu142fl compared with n2NSM. Quantitative RT–PCR (qRT–PCR) analysis of GhNAC230 demonstrated its gradual accumulation from −1 days postanthesis (DPA) to 1 DPA in n2NSM and further confirmed its downregulated expression in 1 DPA ovules of Xu142fl compared to n2NSM. The current study predicted a pair of NAC genes that might be key candidate genes that are crucial for lint fiber development.

Keywords

• fiber initiation
• n2 recessive naked seed mutant (n2NSM)
• NAC transcription factors
• upland cotton
• Xuzhou142 fuzzless–lintless mutant (Xu142fl)