AUTHOR=Zhuang Yuhui , Sharif Yasir , Zeng Xiaohong , Chen Suzheng , Chen Hua , Zhuang Chunhong , Deng Ye , Ruan Miaohong , Chen Shuanglong , Weijian Zhuang 

TITLE=Molecular cloning and functional characterization of the promoter of a novel Aspergillus flavus inducible gene (AhOMT1) from peanut

JOURNAL=Frontiers in Plant Science

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2023.1102181

DOI=10.3389/fpls.2023.1102181

ISSN=1664-462X

ABSTRACT=<p>Peanut is an important oil and food legume crop grown in more than one hundred countries, but the yield and quality are often impaired by different pathogens and diseases, especially aflatoxins jeopardizing human health and causing global concerns. For better management of aflatoxin contamination, we report the cloning and characterization of a novel <italic>A. flavus</italic> inducible promoter of the O-methyltransferase gene (<italic>AhOMT1</italic>) from peanut. The <italic>AhOMT1</italic> gene was identified as the highest inducible gene by <italic>A. flavus</italic> infection through genome-wide microarray analysis and verified by qRT-PCR analysis. <italic>AhOMT1</italic> gene was studied in detail, and its promoter, fussed with the <italic>GUS</italic> gene, was introduced into Arabidopsis to generate homozygous transgenic lines. Expression of <italic><italic>GUS</italic></italic> gene was studied in transgenic plants under the infection of <italic>A. flavus</italic>. The analysis of <italic>AhOMT1</italic> gene characterized by in silico assay, RNAseq, and qRT-PCR revealed minute expression in different organs and tissues with trace or no response to low temperature, drought, hormones, Ca2+, and bacterial stresses, but highly induced by <italic>A. flavus</italic> infection. It contains four exons encoding 297 aa predicted to transfer the methyl group of S-adenosyl-L-methionine (SAM). The promoter contains different cis-elements responsible for its expression characteristics. Functional characterization of <italic>AhOMT1</italic>P in transgenic Arabidopsis plants demonstrated highly inducible behavior only under <italic>A. flavus</italic> infection. The transgenic plants did not show <italic><italic>GUS</italic></italic> expression in any tissue(s) without inoculation of <italic>A. flavus</italic> spores. However, <italic>GUS</italic> activity increased significantly after inoculation of <italic>A. flavus</italic> and maintained a high level of expression after 48 hours of infection. These results provided a novel way for future management of peanut aflatoxins contamination through driving resistance genes in <italic>A. flavus</italic> inducible manner.</p>