AUTHOR=Zhang Hui , Zheng Jiexuan , Su Huaxiang , Xia Kuaifei , Jian Shuguang , Zhang Mei 

TITLE=Molecular Cloning and Functional Characterization of the Dehydrin (IpDHN) Gene From Ipomoea pes-caprae

JOURNAL=Frontiers in Plant Science

VOLUME=9

YEAR=2018

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2018.01454

DOI=10.3389/fpls.2018.01454

ISSN=1664-462X

ABSTRACT=<p>Dehydrin (DHN) genes can be rapidly induced to offset water deficit stresses in plants. Here, we reported on a dehydrin gene (<italic>IpDHN</italic>) related to salt tolerance isolated from <italic>Ipomoea pes-caprae</italic> L. (Convolvulaceae). The IpDHN protein shares a relatively high homology with Arabidopsis dehydrin ERD14 (At1g76180). IpDHN was shown to have a cytoplasmic localization pattern. Quantitative RT-PCR analyses indicated that <italic>IpDHN</italic> was differentially expressed in most organs of <italic>I. pes-caprae</italic> plants, and its expression level increased after salt, osmotic stress, oxidative stress, cold stress and ABA treatments. Analysis of the 974-bp promoter of <italic>IpDHN</italic> identified distinct <italic>cis</italic>-acting regulatory elements, including an MYB binding site (MBS), ABRE (ABA responding)-elements, Skn-1 motif, and TC-rich repeats. The induced expression of <italic>IpDHN</italic> in <italic>Escherichia coli</italic> indicated that IpDHN might be involved in salt, drought, osmotic, and oxidative stresses. We also generated transgenic Arabidopsis lines that over-expressed <italic>IpDHN</italic>. The transgenic Arabidopsis plants showed a significant enhancement in tolerance to salt/drought stresses, as well as less accumulation of hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>) and the superoxide radical (O<sub>2</sub><sup>−</sup>), accompanied by increasing activity of the antioxidant enzyme system <italic>in vivo</italic>. Under osmotic stresses, the overexpression of <italic>IpDHN</italic> in Arabidopsis can elevate the expression of ROS-related and stress-responsive genes and can improve the ROS-scavenging ability. Our results indicated that <italic>IpDHN</italic> is involved in cellular responses to salt and drought through a series of pleiotropic effects that are likely involved in ROS scavenging and therefore influence the physiological processes of microorganisms and plants exposed to many abiotic stresses.</p>