title: Overexpression ofTaNAC2DDisplays Opposite Responses to Abiotic Stresses between Seedling and Mature Stage of TransgenicArabidopsis.
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 ofTaNAC2D, a stress-relatedNAC(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.TaNAC2Dtranscript abundance was significantly induced by NaCl, PEG6000, and abscisic acid (ABA) at seedling stage, and repressed by NaCl and PEG6000 at mature plant stage. WhenTaNAC2Dwas introduced intoArabidopsis, the 35-day-old soil-grownTaNAC2D-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 transgenicArabidopsiswere consistent with the expression patterns ofTaNAC2Din wheat. Moreover, under high salinity and dehydration conditions, three marker genes, includingNCED3,RD29A, andRD29B, were down-regulated in 35-day-oldTaNAC2D-OX plants grown in soil and up-regulated in 14-day-oldTaNAC2D-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.
authors.affiliation: Key Laboratory of Genetic Development and Germplasm Enhancement of Rare Plants in Three Gorges Area, College of Biology and Pharmacy, China Three Gorges University Yichang, China.
authors.forename: Quanjun
authors.initials: Q
authors.lastname: Huang
authors.affiliation: The Genetic Engineering International Cooperation Base of Ministry of Science and Technology, Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology Wuhan, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Wang
keywords: Arabidopsis; NAC; TaNAC2D; stress; wheat