AUTHOR=Hu Xu , Hao Jiangshan , Pan Ling , Xu Tao , Ren Longzhou , Chen Yu , Tang Minqiang , Liao Li , Wang Zhiyong 

TITLE=Genome-wide analysis of tandem duplicated genes and their expression under salt stress in seashore paspalum

JOURNAL=Frontiers in Plant Science

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.971999

DOI=10.3389/fpls.2022.971999

ISSN=1664-462X

ABSTRACT=<p>Seashore paspalum (<italic>Paspalum vaginatum</italic>) is a halophytic, warm-season grass which is closely related to various grain crops. Gene duplication plays an important role in plant evolution, conferring significant plant adaptation at the genomic level. Here, we identified 2,542 tandem duplicated genes (TDGs) in the <italic>P. vaginatum</italic> genome and estimated the divergence time of pairs of TDGs based on synonymous substitution rates (Ks). Expression of <italic>P. vaginatum</italic> TDGs resulted in enrichment in many GO terms and KEGG pathways when compared to four other closely-related species. The GO terms included: “ion transmembrane transporter activity,” “anion transmembrane transporter activity” and “cation transmembrane transport,” and KEGG pathways included “ABC transport.” RNA-seq analysis of TDGs showed tissue-specific expression under salt stress, and we speculated that <italic>P. vaginatum</italic> leaves became adapted to salt stress in the earlier whole-genome duplication (WGD; ~83.3 million years ago; Ma), whereas the entire <italic>P. vaginatum</italic> plant acquired a large number of TDGs related to salt stress in the second WGD (~23.3 Ma). These results can be used as a reference resource to accelerate salt-resistance research in other grasses and crops.</p>