AUTHOR=Tian Tian , Yu Ruimin , Suo Yanyun , Cheng Lixiang , Li Guizhi , Yao Dan , Song Yanjie , Wang Huanjun , Li Xinyu , Gao Gang 

TITLE=A Genome-Wide Analysis of StTGA Genes Reveals the Critical Role in Enhanced Bacterial Wilt Tolerance in Potato During Ralstonia solanacearum Infection

JOURNAL=Frontiers in Genetics

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/genetics/articles/10.3389/fgene.2022.894844

DOI=10.3389/fgene.2022.894844

ISSN=1664-8021

ABSTRACT=<p><italic>TGA</italic> is one of the members of TGACG sequence-specific binding protein family, which plays a crucial role in the regulated course of hormone synthesis as a stress-responsive transcription factor (TF). Little is known, however, about its implication in response to bacterial wilt disease in potato (<italic>Solanum tuberosum</italic>) caused by <italic>Ralstonia solanacearum</italic>. Here, we performed an <italic>in silico</italic> identification and analysis of the members of the <italic>TGA</italic> family based on the whole genome data of potato. In total, 42 <italic>StTGAs</italic> were predicted to be distributed on four chromosomes in potato genome. Phylogenetic analysis showed that the proteins of <italic>StTGAs</italic> could be divided into six sub-families. We found that many of these genes have more than one exon according to the conserved motif and gene structure analysis. The heat map inferred that <italic>StTGAs</italic> are generally expressed in different tissues which are at different stages of development. Genomic collinear analysis showed that there are homologous relationships among potato, tomato, pepper, Arabidopsis, and tobacco <italic>TGA</italic> genes. Cis-element <italic>in silico</italic> analysis predicted that there may be many cis-acting elements related to abiotic and biotic stress upstream of <italic>StTGA</italic> promoter including plant hormone response elements. A representative member <italic>StTGA39</italic> was selected to investigate the potential function of the <italic>StTGA</italic> genes for further analysis. Quantitative real-time polymerase chain reaction (qRT-PCR) assays indicated that the expression of the <italic>StTGAs</italic> was significantly induced by <italic>R. solanacearum</italic> infection and upregulated by exogenous salicylic acid (SA), abscisic acid (ABA), gibberellin 3 (GA<sub>3</sub>), and methyl jasmonate (MeJA). The results of yeast one-hybrid (Y1H) assay showed that <italic>StTGA39</italic> regulates <italic>S. tuberosum</italic> BRI1-associated receptor kinase 1 (<italic>StBAK1</italic>) expression. Thus, our study provides a theoretical basis for further research of the molecular mechanism of the <italic>StTGA</italic> gene of potato tolerance to bacterial wilt.</p>