Knockdown of Cytochrome P450 Genes Gh_D07G1197 and Gh_A13G2057 on Chromosomes D07 and A13 Reveals Their Putative Role in Enhancing Drought and Salt Stress Tolerance in Gossypium hirsutum

Abstract

We identified 672, 374, and 379 CYPs proteins encoded by the CYPs genes in Gossypium hirsutum, Gossypium raimondii, and Gossypium arboreum, respectively. The genes were found to be distributed in all 26 chromosomes of the tetraploid cotton, with chrA05, chrA12, and their homeolog chromosomes harboring the highest number of genes. The physiochemical properties of the proteins encoded by the CYP450 genes varied in terms of their protein lengths, molecular weight, isoelectric points (pI), and even grand hydropathy values (GRAVY). However, over 99% of the cotton proteins had GRAVY values below 0, which indicated that the majority of the proteins encoded by the CYP450 genes were hydrophilic in nature, a common property of proteins encoded by stress-responsive genes. Moreover, through the RNA interference (RNAi) technique, the expression levels of Gh_D07G1197 and Gh_A13G2057 were suppressed, and the silenced plants showed a higher concentration of hydrogen peroxide (H2O2) with a significant reduction in the concentration levels of glutathione (GSH), ascorbate peroxidase (APX), and proline compared to the wild types under drought and salt stress conditions. Furthermore, the stress-responsive genes 1-Pyrroline–5-Carboxylate Synthetase (GhP5CS), superoxide dismutase (GhSOD), and myeloblastosis (GhMYB) were downregulated in VIGS plants, but showed upregulation in the leaf tissues of the wild types under drought and salt stress conditions. In addition, CYP450-silenced cotton plants exhibited a high level of oxidative injury due to high levels of oxidant enzymes, in addition to negative effects on CMS, ELWL, RLWC, and chlorophyll content The results provide the basic foundation for future exploration of the proteins encoded by the CYP450 genes in order to understand the physiological and biochemical mechanisms in enhancing drought and salt stress tolerance in plants.

Genome-wide identification of OSCA gene family and their potential function in the regulation of dehydration and salt stress in Gossypium hirsutum

“…8a). The appearance of the albino-like trait showed that the vector used was effective, and the results were in agreement to previous findings in which PDS has been used to monitor the effectiveness of the vector in the knockdown of cytochrome P450 genes in upland cotton (Magwanga et al 2019b). The VIGS plants, the positively controlled and the wild types were exposed to drought and salt stress, and the VIGS plants ability to tolerate the effects of drought and salt stress were highly compromised.…”

“…A large number of OSCA gene family members (Shan et al 2005) in G. hirsutum may be related to the whole genome replication of cotton. But queerly, compared with the number of OSCA genes of diploid A and D genome donor species, G. arboreum (Magwanga et al 2018) and G. raimondii (Magwanga et al 2019b), the allotetraploid species G. hirsutum (Shan et al 2005) showed fewer OSCA members. This result suggested that there was possible gene loss and/or as a result of chromosome rearrangement during the history of chromosome doubling and plant evolution.…”

Genetic regulatory networks for salt-alkali stress in Gossypium hirsutum with differing morphological characteristics

“…The composition of the salt-alkali solution was formulated by combining CaCl 2 (0.0970 molL − 1 ), NaHCO 3 (0.0086 molL − 1 ), Na 2 SO 4 (0.1411molL − 1 ), K 2 SO 4 (0.0097 molL − 1 ), MgSO 4 .7H 2 O (0.0583 molL − 1 ), with pH set at 7.50 [55]. Roots and leaves were collected at 0 h, 3 h, 12 h and 48 h time points after salt-alkali stress treatment, as previously described by Magwanga et al [56], in the determination of the role of proteins encoded by the CYP450 genes in cotton under drought and salt stress conditions. Then, collected samples were used for transcriptome sequencing.…”

Comparative transcriptome analysis reveals evolutionary divergence and shared network of cold and salt stress response in diploid D-genome cotton

“…We perform the virus induced gene silencing (VIGS) of candidate genes, RALF and FLA, in G. hirsutum race Marie-Galante 85 according to the strategy of our previous published study [45,46]. Firstly, we construct the VIGS vector of TRV:: RALF, TRV:: FLA and TRV:: PDS and introduced into Agrobacterium tumefaciens strain GV4104.…”