biologia plantarum

Biologia plantarum 66:29-38, 2022 | DOI: 10.32615/bp.2021.061

Heat stress transcription factor DcHsfA1d isolatedfrom Dianthus caryophyllus enhances thermotoleranceand salt tolerance of transgenic Arabidopsis

X.L. WAN^{1, 2}, Y. Y. SUN¹, Y. FENG¹, M.Z. BAO², J.W. ZHANG^{2, *}

¹ College of Landscape and Forestry, Qingdao Agricultural University, Qingdao 266109, Shandong, P.R. China

² Key Laboratory of Horticultural Plant Biology, Ministry of Education, College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan 430070, P.R. China

Heat shock transcription factors (Hsfs) participate in a variety of plant physiological processes including the regulation of transcription factors associated with thermotolerance. Here, a Hsf gene DcHsfA1d was identified from carnation (Dianthus caryophyllus L.). The open reading frame (ORF) of DcHsfA1d was 1 368 bp and encoded a protein of 455 amino acids with a molecular mass of 51.039 kDa and an isoelectric point of 4.94. Sequence domain prediction revealed that DcHsfA1d protein exhibited five typical functional features and motifs. The transcription of DcHsfA1d was significantly up-regulated under heat stress or ABA treatment. Yeast two-hybrid experiment indicated that DcHsfA1d and DcHsp70 physically interact with each other. Overexpression of DcHsfA1d in Arabidopsis ecotype Columbia enhanced seedling thermotolerance by increasing the activities of catalase, peroxidase, and superoxide dismutase while reducing relative electrolyte leakage, malondialdehyde content, accumulation of O₂^- and H₂O₂ and by initiating transcriptional regulation of thermal protective gene expression under heat stress. Furthermore, under salt stress, the root length and fresh mass of Arabidopsis ectopically expressing DcHsfA1d were significantly higher than those of wild type, which indicated that the salt tolerance of transgenic Arabidopsis was improved to a certain extent. In summary, DcHsfA1d was demonstrated to play a positive regulatory role in heat stress response and it might be a candidate gene for salt tolerance using genetic modification.

Keywords: carnation, Dianthus caryophyllus L., heat shock transcription factors, salt tolerance, thermotolerance, transgenic plants.

Received: March 12, 2021; Revised: August 20, 2021; Accepted: October 6, 2021; Published online: February 23, 2022  Show citation