AUTHOR=Gao Pengchao , Xiao Jiancai , Guo Wanying , Fan Rui , Zhang Yan , Nan Tiegui 

TITLE=Genome-wide identification of Glycyrrhiza uralensis Fisch. MAPK gene family and expression analysis under salt stress relieved by Bacillus subtilis

JOURNAL=Frontiers in Genetics

VOLUME=15

YEAR=2024

URL=https://www.frontiersin.org/journals/genetics/articles/10.3389/fgene.2024.1442277

DOI=10.3389/fgene.2024.1442277

ISSN=1664-8021

ABSTRACT=<p><bold>Introduction:</bold> Research on <italic>Glycyrrhiza uralensis</italic>, a nonhalophyte that thrives in saline–alkaline soil and a traditional Chinese medicinal component, is focused on improving its ability to tolerate salt stress to increase its productivity and preserve its “Dao-di” characteristics. Furthermore, the inoculation of bioagents such as <italic>Bacillus subtilis</italic> to increase plant responses to abiotic stressors is currently a mainstream strategy. Mitogen-activated protein kinase (MAPK), a highly conserved protein kinase, plays a significant role in plant responses to various abiotic stress pathways.</p><p><bold>Methods:</bold> This investigation involved the identification of 21 members of the <italic>GuMAPK</italic> family from the genome of <italic>G</italic>. <italic>uralensis</italic>, with an analysis of their protein conserved domains, gene structures, evolutionary relationships, and phosphorylation sites using bioinformatics tools.</p><p><bold>Results:</bold> Systematic evolutionary analysis of the 21 <italic>GuMAPKs</italic> classified them into four distinct subgroups, revealing significant differences in gene structure and exon numbers. Collinearity analysis highlighted the crucial role of segmental duplication in expanding the <italic>GuMAPK</italic> gene family, which is particularly evident in <italic>G. uralensis</italic> and shows a close phylogenetic relationship with <italic>Arabidopsis thaliana</italic>, tomato, and cucumber. Additionally, the identification of phosphorylation sites suggests a strong correlation between <italic>GuMAPK</italic> and various physiological processes, including hormonal responses, stress resistance, and growth and development. Protein interaction analysis further supported the role of <italic>GuMAPK</italic> proteins in regulating essential downstream genes. Through examination of transcriptome expression patterns, <italic>GuMAPK16-2</italic> emerged as a prospective pivotal regulatory factor in the context of salt stress and <italic>B. subtilis</italic> inoculation, a finding supported by its subcellular localization within the nucleus.</p><p><bold>Discussion:</bold> These discoveries offer compelling evidence for the involvement of GuMAPK in the salt stress response and for the exploration of the mechanisms underlying <italic>B. subtilis</italic>’ enhancement of salt tolerance in <italic>G. uralensis</italic>.</p>