AUTHOR=Chen Shuangshuang , Yu Miao , Li He , Wang Ying , Lu Zhuchou , Zhang Yunxing , Liu Mingying , Qiao Guirong , Wu Longhua , Han Xiaojiao , Zhuo Renying 

TITLE=SaHsfA4c From Sedum alfredii Hance Enhances Cadmium Tolerance by Regulating ROS-Scavenger Activities and Heat Shock Proteins Expression

JOURNAL=Frontiers in Plant Science

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2020.00142

DOI=10.3389/fpls.2020.00142

ISSN=1664-462X

ABSTRACT=<p>The heat shock transcription factor (Hsf) family, an important member in plant stress response, affects cadmium (Cd) tolerance in plants. In this study, we identified and functionally characterized a transcript of the Hsf A4 subgroup from <italic>Sedum alfredii</italic>. Designated as <italic>SaHsfA4c</italic>, the open reading frame was 1,302 bp long and encoded a putative protein of 433 amino acids containing a complete DNA-binding domain (DBD). Heterologous expression of <italic>SaHsfA4c</italic> in yeast enhanced Cd stress tolerance and accumulation, whereas expression of the alternatively spliced transcript <italic>InSaHsfA4c</italic> which contained an intron and harbored an incomplete DBD, resulted in relatively poor Cd stress tolerance and low Cd accumulation in transgenic yeast. The function of <italic>SaHsfA4c</italic> under Cd stress was characterized in transgenic <italic>Arabidopsis</italic> and non-hyperaccumulation ecotype <italic>S. alfredii</italic>. <italic>SaHsfA4c</italic> was able to rescue the Cd sensitivity of the <italic>Arabidopsis athsfa4c</italic> mutant. <italic>SaHsfA4c</italic> reduced reactive oxygen species (ROS) accumulation and increased the expression of ROS-scavenging enzyme genes and <italic>Hsps</italic> in transgenic lines. The present results suggest that <italic>SaHsfA4c</italic> increases plant resistance to stress by up-regulating the activities of ROS-scavenging enzyme and the expression of <italic>Hsps</italic>.</p>