Genome-Wide Analysis of the Role of NAC Family in Flower Development and Abiotic Stress Responses in .

Plant-specific NAC (, , ) transcription factor (TF) family plays important roles in biological processes such as plant growth and response to stress. Nevertheless, no information is known about NAC TFs in , a prominent xerophyte desert grass in northwestern China. In this study, 162 genes were found from the genome, among which 156 () genes (96.3%) were mapped onto 20 chromosomes. The phylogenetic tree constructed by CsNAC and rice NAC TFs can be separated into 14 subfamilies. Syntenic and Ka/Ks analyses showed that were primarily expanded by genomewide replication events, and purifying selection was the primary force driving the evolution of family genes. The gene expression profiles showed that 36 genes showed differential expression between cleistogamous (CL) and chasmogamous (CH) flowers. One hundred and two genes showed differential expression under heat, cold, drought, salt and ABA treatment. Twenty-three genes were commonly differentially expressed both under stress responses and during dimorphic floret development. Gene Ontology (GO) annotation, coexpression network and qRT-PCR tests revealed that these genes may simultaneously regulate dimorphic floret development and the response to stress. Our results may help to characterize the NAC transcription factors in and provide new insights into the functional research and application of the NAC family in crop improvement, especially in dimorphic floret plants.