AUTHOR=Lu Lu , Chen Xinying , Zhu Liming , Li Mengjuan , Zhang Jingbo , Yang Xiuyan , Wang Pengkai , Lu Ye , Cheng Tielong , Shi Jisen , Yi Yin , Chen Jinhui 

TITLE=NtCIPK9: A Calcineurin B-Like Protein-Interacting Protein Kinase From the Halophyte Nitraria tangutorum, Enhances Arabidopsis Salt Tolerance

JOURNAL=Frontiers in Plant Science

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2020.01112

DOI=10.3389/fpls.2020.01112

ISSN=1664-462X

ABSTRACT=<p>Calcineurin B-like protein-interacting protein kinases (<italic>CIPKs</italic>) play essential roles in plant abiotic stress response. In order to better understand salt tolerance, we cloned and analyzed the <italic>NtCIPK9</italic> gene from the halophyte <italic>Nitraria tangutorum</italic>. Phylogenetic analysis shows that <italic>NtCIPK9</italic> belongs to a sister clade with the <italic>Arabidopsis AtCIPK9</italic> gene and is thought to localize to the plasma membrane. <italic>NtCIPK9</italic> shows the highest expression level in the <italic>Nitraria tangutorum</italic> root under normal growth conditions, whereas after NaCl treatment, the highest expression was found in the blade. <italic>NtCIPK9</italic>-overexpressing Arabidopsis plants have a higher seed germination rate, longer root length, and displayed higher salt tolerance than wild type seedlings under salt stress conditions. Furthermore, <italic>NtCIPK9</italic> overexpression might enhance the expression of genes related to K<sup>+</sup> transportation after NaCl treatment. Thus, we conclude that <italic>NtCIPK9</italic> increases transgenic plant salt tolerance and reduces damage associated with salt stress by promoting the expression of genes controlling ion homeostasis. Our results suggest that <italic>NtCIPK9</italic> could serve as an ideal candidate gene to genetically engineer salt-tolerant plants.</p>