Knockdown of ghAlba_4 and ghAlba_5 Proteins in Cotton Inhibits Root Growth and Increases Sensitivity to Drought and Salt Stresses

Abstract

We found 33, 17, and 20 Alba genes in Gossypium hirsutum, Gossypium arboretum, and Gossypium raimondii, respectively. The Alba protein lengths ranged from 62 to 312 aa, the molecular weight (MW) from 7.003 to 34.55 kDa, grand average hydropathy values of −1.012 to 0.609 and isoelectric (pI) values of −3 to 11. Moreover, miRNAs such as gra-miR8770 targeted four genes, gra-miR8752 and gra-miR8666 targeted three genes, and each and gra-miR8657 a, b, c, d, e targeted 10 genes each, while the rests targeted 1 to 2 genes each. Similarly, various cis-regulatory elements were detected with significant roles in enhancing abiotic stress tolerance, such as CBFHV (RYCGAC) with a role in cold stress acclimation among others. Two genes, Gh_D01G0884 and Gh_D01G0922, were found to be highly induced under water deficit and salt stress conditions. Through virus-induced gene silencing (VIGS), the VIGS cotton plants were found to be highly susceptible to both water deficit and salt stresses; the VIGS plants exhibited a significant reduction in root growth, low cell membrane stability (CMS), saturated leaf weight (SLW), chlorophyll content levels, and higher excised leaf water loss (ELWL). Furthermore, the stress-responsive genes and ROS scavenging enzymes were significantly reduced in the VIGS plants compared to either the wild type (WT) and or the positively controlled plants. The VIGS plants registered higher concentration levels of hydrogen peroxide and malondialdehyde, with significantly lower levels of the various antioxidants evaluated an indication that the VIGS plants were highly affected by salt and drought stresses. This result provides a key foundation for future exploration of the Alba proteins in relation to abiotic stress.

Characterization of ALBA Family Expression and Localization in Arabidopsis thaliana Generative Organs

“…Similarly, Trypanosoma brucei ALBAs were detected in association with mRNAs, exclusively in cytoplasmic stress granules following nutrient stress [ 7 , 8 ]. In plants, ALBA proteins have also been connected to various stress responses [ 10 , 14 , 15 ]. In rice seedlings, significant changes in the relative expression of ALBA genes were demonstrated following various abiotic stress and phytohormone treatments [ 10 ].…”

“…Similarly, differential expression upon abiotic stress application (water and salt stress) was observed for ALBA genes in Gossypium hirsutum (cotton) leaves, roots, and stems. In leaves and roots, two genes GhALBA_4 and GhALBA_5 were significantly upregulated [ 14 ]. Transgenic plants with reduced expression of these genes were shown to be more sensitive to drought and salt stress [ 14 ].…”

“…In leaves and roots, two genes GhALBA_4 and GhALBA_5 were significantly upregulated [ 14 ]. Transgenic plants with reduced expression of these genes were shown to be more sensitive to drought and salt stress [ 14 ]. Moreover, AtALBA1 , AtALBA2 , AtALBA4 , AtALBA5, and AtALBA6 enrichment was detected in the mRNA binding proteome of Arabidopsis four-day-old etiolated seedlings [ 15 ].…”

The ABI4‐RbohD/VTC2 regulatory module promotes reactive oxygen species (ROS) accumulation to decrease seed germination under salinity stress

“…Since high ROS concentrations impaired cell membrane stability (Mittler, 2002(Mittler, , 2006Magwanga et al, 2019) and directly influenced seed vigor, we subsequently investigated seed vigor in the tested genotypes under salt application conditions. From the seed staining results on ½MS medium, it was observed that seed vigor was comparable among different genotypes, and the exogenous salt treatment decreased seed vigor among all of the tested genotypes (Fig.…”

Genome-wide identification and expression profiling of Alba gene family members in response to abiotic stress in tomato (Solanum lycopersicum L.)

“…Mild heat stress (37 •C) altered the expression of most Arabidopsis Alba genes in in orescences (Náprstková et al, 2021). In cotton (Gossypium hirsutum), GhALBA4 and GhALBA5 were signi cantly induced by water de cit and salinity treatment, and plants in which the expression of these genes was repressed by virus-induced gene silencing (VIGS) were highly sensitive to dehydration as well as salt stress, pointing to their putative roles in abiotic stress tolerance (Magwanga et al, 2019).…”