A flavonol synthase (FLS) gene, GhFLS1, was screened out increasing salt resistance in cotton

Abstract

AbstractBackgroundFlavonols play important roles in antioxidation and anticancer activities, longevity, and cardiovascular protection.Flavonol synthase(FLS) is a key enzyme for flavonol synthesis.ResultPhenotypic, transcriptional and metabolic data were analyzed, which showed that there was a close relationship between salt stress and flavonoids, and flavonols were significantly upregulated under salt stress. Nine, seven, four, and fourFLSgenes were identified inGossypium hirsutum,Gossypium barbadense,Gossypium arboreum, andGossypium raimondii,respectively. The results of subcellular localization showed that FLS existed in the nucleus and cytoplasmic. Through phylogenetic analysis, 24FLSgenes were divided into three subfamilies. The results of the RNA sequencing showed that the expression ofGhFLSgenes was mainly induced by salt, drought, low temperature, and heat stress.GhFLSpromoter mainly comprised plant hormone response elements and abiotic stress elements, indicating that theGhFLSgene may play a key role in abiotic stress response. The proline contents of pYL156:GhFLS1 was reduced significantly compared to pYL156 under salt stress, thereby reducing the resistance of cotton to salt stress.ConclusionThis study will lay a foundation for further study on the antioxidant regulation mechanism of theFLSgene under abiotic stress.