AUTHOR=Chen Yahui , Zhang Xuanyi , Fan Yunlong , Sui Dezong , Jiang Jiang , Wang Lei 

TITLE=The role of WRKY transcription factors in exogenous potassium (K+) response to NaCl stress in Tamarix ramosissima

JOURNAL=Frontiers in Genetics

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/genetics/articles/10.3389/fgene.2023.1274288

DOI=10.3389/fgene.2023.1274288

ISSN=1664-8021

ABSTRACT=<p><bold>Introduction:</bold> Soil salinization poses a significant challenge to plant growth and vitality. Plants like <italic>Tamarix ramosissima</italic> Ledeb (<italic>T. ramosissima</italic>), which are halophytes, are often integrated into planting schemes tailored for saline environments. Yet, the role of WRKY transcription factors in <italic>T. ramosissima</italic>, especially under sodium chloride (NaCl) stress mitigated by exogenous K<sup>+</sup> application, is not well-understood. This research endeavors to bridge this knowledge gap.</p><p><bold>Methods:</bold> Using Pfam protein domain prediction and physicochemical property analysis, we delved into the WRKY genes in <italic>T. ramosissima</italic> roots that are implicated in counteracting NaCl stress when aided by exogenous K<sup>+</sup> applications. By observing shifts in the expression levels of WRKY genes annotated to the KEGG pathway under NaCl stress at 0, 48, and 168 h, we aimed to identify potential key WRKY genes.</p><p><bold>Results:</bold> We found that the expression of 56 WRKY genes in <italic>T. ramosissima</italic> roots responded to exogenous K<sup>+</sup> application during NaCl stress at the indicated time points. Particularly, the expression levels of these genes were primarily upregulated within 168 h. From these, 10 WRKY genes were found to be relevant in the KEGG pathways. Moreover, six genes, namely <italic>Unigene0024962</italic>, <italic>Unigene0024963</italic>, <italic>Unigene0010090</italic>, <italic>Unigene0007135</italic>, <italic>Unigene0070215</italic>, and <italic>Unigene0077293</italic>, were annotated to the Plant-pathogen interaction pathway or the MAPK signaling pathway in plants. These genes exhibited dynamic expression regulation at 48 h with the application of exogenous K<sup>+</sup> under NaCl stress.</p><p><bold>Discussion:</bold> Our research highlights that WRKY transcription factors can modulate the activation or inhibition of related genes during NaCl stress with the application of exogenous K<sup>+</sup>. This regulation enhances the plant’s adaptability to saline environments and mitigates the damage induced by NaCl. These findings provide valuable gene resources for future salt-tolerant <italic>Tamarix</italic> breeding and expand our understanding of the molecular mechanisms of WRKY transcription factors in alleviating NaCl toxicity.</p>