Identification of Raf-Like Kinases B Subfamily Genes in Gossypium Species Revealed GhRAF42 Enhanced Salt Tolerance in Cotton

Abstract

Salinity is a critical abiotic factor that significantly reduces agricultural production. Cotton is an important fiber crop and a pioneer on saline soil, hence genetic architecture that underpins salt tolerance should be thoroughly investigated. The Raf-like kinase B-subfamily (RAF) genes were discovered to regulate the salt stress response in cotton plants. However, understanding the RAFs in cotton, such as Enhanced Disease Resistance 1 and Constitutive Triple Response 1 kinase, remains a mystery. This study obtained 29, 28, 56, and 54 RAF genes from G. arboreum, G. raimondii, G. hirsutum, and G. barbadense, respectively. The RAF gene family described allopolyploidy and hybridization events in allotetraploid cotton evolutionary connections. Ka/Ks analysis advocates that cotton evolution was subjected to an intense purifying selection of the RAF gene family. Interestingly, integrated analysis of synteny and gene collinearity suggested dispersed and segmental duplication events involved in the extension of RAFs in cotton. Transcriptome studies, functional validation, and virus-induced gene silencing on salt treatments revealed that GhRAF42 is engaged in salt tolerance in upland cotton. This research might lead to a better understanding of the role of RAFs in plants and the identification of suitable candidate salt-tolerant genes for cotton breeding.

Integrative physiology and transcriptome reveal differences between G. hirsutum and G. barbadense in response to salt stress and the identification of key salt tolerance genes

“…Thus, we could conclude that there is a set of basic and broad-spectrum metabolic pathways that respond to salt stress in TM-1 and H7124. These results are consistent with some previous reports [21,33,38]. In addition, we found there were differences in resistance between TM-1 and H7124, which is linked to speci c response mechanisms and countermeasures.…”

“…Obviously, there are time-speci c in response to salt stress for these genes (Fig. 10B-K), which are consistent with some previous report [33]. These genes provide the basis for the study of salt tolerance mechanisms and molecular breeding of cotton.…”

“…4B). In general, salttolerant genotypes induce fewer genes in response to salt stress [33]. These ndings align with previous research conducted on other plants [34][35][36][37].…”

Transcriptomic analysis reveals the beneficial effects of salt priming on enhancing defense responses in upland cotton under successive salt stress

“…The high number of unique DEGs in T compared to other genotypes indicates its reservoir of genetic diversity. Modern upland cotton varieties have faced genetic bottlenecks due to intensive selection, resulting in erosion of stress tolerance traits (Peng et al, 2023; Cheng et al, 2023). G. hirsutum purpurascens represents untapped adaptive potential that could be introgressed into elite cultivars to improve salinity tolerance.…”