Overexpression of TaNAC2D Displays Opposite Responses to Abiotic Stresses between Seedling and Mature Stage of Transgenic Arabidopsis

Abstract

Environmental stresses frequently affect plant growth and development, and many genes have been found to be induced by unfavorable environmental conditions. Here, we reported the biological functions of TaNAC2D, a stress-related NAC (NAM, ATAF, and CUC) gene from wheat. TaNAC2D showed transcriptional activator activity in yeast. TaNAC2D-GFP fusion protein was localized in the nucleus of wheat mesophyll protoplasts. TaNAC2D transcript abundance was significantly induced by NaCl, PEG6000, and abscisic acid (ABA) at seedling stage, and repressed by NaCl and PEG6000 at mature plant stage. When TaNAC2D was introduced into Arabidopsis, the 35-day-old soil-grown TaNAC2D-overexpression (TaNAC2D-OX) plants displayed slower stomatal closure, higher water loss rate, and more sensitivity to salt and drought stresses compared with WT plants. In contrast, TaNAC2D-OX seedlings, grown on 1/2 MS medium supplemented with different concentrations of NaCl, Mannitol, and MV, had enhanced tolerances to salt, osmotic and oxidative stresses during seed germination and post-germination periods. The opposite stress-responsive phenotypes of transgenic Arabidopsis were consistent with the expression patterns of TaNAC2D in wheat. Moreover, under high salinity and dehydration conditions, three marker genes, including NCED3, RD29A, and RD29B, were down-regulated in 35-day-old TaNAC2D-OX plants grown in soil and up-regulated in 14-day-old TaNAC2D-OX seedlings grown on 1/2 MS medium. Our results suggest that the change in growth stages and environmental conditions may regulate TaNAC2D’s function.

Genome-wide analysis, expansion and expression of the NAC family under drought and heat stresses in bread wheat (T. aestivum L.)

“…For example, Arabidopsis overexpressing TaNAC2 , TaNAC29 , or TaNAC67 display improved tolerance to multiple abiotic stresses [16,42,75]. In the same way, TaNAC2a , TaNAC2D , TaNAC4a , TaNAC6 , TaNAC7 , TaNAC13 , and TaNTL5 were induced by water stress, high salinity, and/or low temperature, at different intensities [76,77]. Recently, TaRNAC1 was found to enhance drought tolerance leading to higher biomass, grain yield, and root length [78].…”

MdWRKY9 overexpression confers intensive dwarfing in the M26 rootstock of apple by directly inhibiting brassinosteroid synthetase MdDWF4 expression

“…The pCL‐1 vector encoding the full‐length GAL4 protein and the empty pGBKT7 vector were used as positive and negative controls, respectively. The Saccharomyces cerevisiae AH109 yeast strain was transformed with the above constructs, and the yeast assay was performed as described previously (Peng et al ., ; Huang & Wang, ). Each experiment was independently repeated three times.…”

Large-Scale Cloning and Comparative Analysis of TaNAC Genes in Response to Stripe Rust and Powdery Mildew in Wheat (Triticum aestivum L.)

“…Samples used in cloning were collected from 2.5 leaf-development stages under pathogen-infection conditions, but did not include different developmental samples and tissue types. It has been suggested that numerous NACs vary dramatically in different tissue types and developmental stages [ 38 , 46 ]. This hints that numerous TaNAC transcripts have not yet been identified, which warrants further exploration.…”