Genome-wide identification and functional analysis of GhFAR gene family in cotton

Fatty acyl-CoA reductase (FAR) is involved in plant wax synthesis and plays an important role in plant growth and development. However, FAR genes and their expression patterns in cotton remains further study. In this study, GhFAR genes were identified by bioinformatics, and chromosomal location, gene sequence and expression profile of GhFAR were analyzed. Furthermore, the function of GhFAR was analyzed by virus-induced gene silencing (VIGS). The results showed that G. hirsutum contains five pairs of homoeologous FAR genes (GhFAR1 to GhFAR5). It was divided into two subfamilies, which are distributed on six chromosomes. The coding proteins contain NAD-binding-4 and sterile conserved domains, which are relatively conservative in evolution. In leaves, the expression level of GhFAR3 was the highest. After silencing GhFAR3, the expression of GhWSD, a wax synthesis related gene, was significantly decreased. The total wax content and relative water content of leaves decreased by 62.5% and 13.67%, respectively. Under drought stress, the expression of genes related to wax synthesis increased. The total wax content of plants silencing GhFAR3 increased by 30.8%-60%, and the relative water content of leaves decreased by 7.79%-11.94%. GhFAR gene family was identified and their expression pattern was analyzed in Gossypium hirsutum. The results of this study will help to understand the function of GhFAR and provides the basis for further study on the molecular regulation mechanism of GhFAR in cotton development and lipid synthesis.