Journal Article

Heat-response patterns of the heat shock transcription factor family in advanced development stages of wheat (Triticum aestivum L.) and thermotolerance-regulation by TaHsfA2–10

Guo, Xiu-lin, Li, Guo-liang, Zhang, Hua-ning, Yuan, Sai-nan, Li, Ya-qing, Zhang, Yuan-yuan, Wang, Gui-yan, Zhang, Yu-jie

2020

Overview

Background Heat shock transcription factors ( Hsf s) are present in majority of plants and play central roles in thermotolerance, transgenerational thermomemory, and many other stress responses. Our previous paper identified at least 82 H sf members in a genome-wide study on wheat ( Triticum aestivum L.). In this study, we analyzed the Hsf expression profiles in the advanced development stages of wheat, isolated the markedly heat-responsive gene TaHsfA2–10 (GenBank accession number MK922287), and characterized this gene and its role in thermotolerance regulation in seedlings of Arabidopsis thaliana (L. Heynh.) . Results In the advanced development stages, wheat Hsf family transcription profiles exhibit different expression patterns and varying heat-responses in leaves and roots, and Hsf s are constitutively expressed to different degrees under the normal growth conditions. Overall, the majority of group A and B Hsf s are expressed in leaves while group C Hsf s are expressed at higher levels in roots. The expression of a few Hsf genes could not be detected. Heat shock (HS) caused upregulation about a quarter of genes in leaves and roots, while a number of genes were downregulated in response to HS. The highly heat-responsive gene TaHsfA2–10 was isolated through homeologous cloning. qRT-PCR revealed that TaHsfA2–10 is expressed in a wide range of tissues and organs of different development stages of wheat under the normal growth conditions. Compared to non-stress treatment, TaHsfA2–10 was highly upregulated in response to HS, H 2 O 2, and salicylic acid (SA), and was downregulated by abscisic acid (ABA) treatment in two-leaf-old seedlings. Transient transfection of tobacco epidermal cells revealed subcellular localization of TaHsfA2–10 in the nucleus under the normal growth conditions. Phenotypic observation indicated that TaHsfA2–10 could improve both basal thermotolerance and acquired thermotolerance of transgenic Arabidopsis thaliana seedlings and rescue the thermotolerance defect of the T-DNA insertion mutant athsfa2 during HS. Compared to wild type (WT) seedlings, the TaHsfA2–10 -overexpressing lines displayed both higher chlorophyll contents and higher survival rates. Yeast one-hybrid assay results revealed that TaHsfA2–10 had transactivation activity. The expression levels of thermotolerance-related AtHsps in the TaHsfA2–10 transgeinc Arabidopsis thaliana were higher than those in WT after HS. Conclusions Wheat Hsf family members exhibit diversification and specificity of transcription expression patterns in advanced development stages under the normal conditions and after HS. As a markedly responsive transcriptional factor to HS, SA and H 2 O 2 , TaHsfA2–10 involves in thermotolerance regulation of plants through binding to the HS responsive element in promoter domain of relative Hsps and upregulating the expression of Hsp genes.

• Publisher: BioMed Central,BioMed Central Ltd,Springer Nature B.V,BMC
• Subject: Abscisic acid / Agricultural production / Agriculture / Arabidopsis - genetics / Arabidopsis thaliana / Binding activity / Biomedical and Life Sciences / Chlorophyll / Cloning / Cytoplasm / Deoxyribonucleic acid / Developmental stages / DNA / DNA binding proteins / DNA, Complementary / Eexpression pattern / Gene expression / Genes / Genetic engineering / genetically modified organisms / Genomes / Genomics / Growth conditions / Heat / Heat shock / Heat shock factors / Heat shock transcription factor / Heat Shock Transcription Factors - genetics / Heat Shock Transcription Factors - metabolism / heat stress / heat tolerance / Hydrogen peroxide / Leaves / Life Sciences / Localization / mutants / Mutation / Nuclei (cytology) / Organs / phenotype / Plant Proteins - genetics / Plant Proteins - metabolism / Plant Sciences / Plant-abiotic interactions / Proteins / Regulatory sequences / Research Article / Roots / Salicylic acid / Salinity / Seedlings / Survival / T-DNA / Temperature tolerance / Thermotolerance / Thermotolerance - genetics / Tobacco / Transcription activity / Transcription factors / transcriptional activation / Transcriptome / Transfection / Transgenic plants / Tree Biology / Triticum - genetics / Triticum - growth & development / Triticum aestivum / Wheat / Yeast / yeasts