AUTHOR=Wang Yiting , Zou Jie , Li Jiali , Kong Fanna , Xu Lina , Xu Dafeng , Li Jiaxin , Yang Huaying , Zhang Lin , Li Tingchun , Fan Honghong 

TITLE=Identification and functional analysis of ZmDLS associated with the response to biotic stress in maize

JOURNAL=Frontiers in Plant Science

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2023.1162826

DOI=10.3389/fpls.2023.1162826

ISSN=1664-462X

ABSTRACT=<p>Terpenes are the main class of secondary metabolites produced in response to pest and germ attacks. In maize (<italic>Zea mays</italic> L.), they are the essential components of the herbivore-induced plant volatile mixture, which functioned as a direct or indirect defense against pest and germ attacks. In this study, 43 maize terpene synthase gene (<italic>ZmTPS</italic>) family members were systematically identified and analyzed through the whole genomes of maize. Nine genes, including <italic>Zm00001d032230</italic>, <italic>Zm00001d045054</italic>, <italic>Zm00001d024486</italic>, <italic>Zm00001d004279</italic>, <italic>Zm00001d002351</italic>, <italic>Zm00001d002350</italic>, <italic>Zm00001d053916</italic>, <italic>Zm00001d015053</italic>, and <italic>Zm00001d015054</italic>, were isolated for their differential expression pattern in leaves after corn borer (<italic>Ostrinia nubilalis</italic>) bite. Additionally, six genes (<italic>Zm00001d045054</italic>, <italic>Zm00001d024486</italic>, <italic>Zm00001d002351</italic>, <italic>Zm00001d002350</italic>, <italic>Zm00001d015053</italic>, and <italic>Zm00001d015054</italic>) were significantly upregulated in response to corn borer bite. Among them, <italic>Zm00001d045054</italic> was cloned. Heterologous expression and enzyme activity assays revealed that <italic>Zm00001d045054</italic> functioned as <sc>d</sc>-limonene synthase. It was renamed <italic>ZmDLS</italic>. Further analysis demonstrated that its expression was upregulated in response to corn borer bites and <italic>Fusarium graminearum</italic> attacks. The mutant of <italic>ZmDLS</italic> downregulated the expressions of <italic>Zm00001d024486</italic>, <italic>Zm00001d002351</italic>, <italic>Zm00001d002350</italic>, <italic>Zm00001d015053</italic>, and <italic>Zm00001d015054</italic>. It was more attractive to corn borer bites and more susceptible to <italic>F. graminearum</italic> infection. The yeast one-hybrid assay and dual-luciferase assay showed that ZmMYB76 and ZmMYB101 could upregulate the expression of <italic>ZmDLS</italic> by binding to the promoter region. This study may provide a theoretical basis for the functional analysis and transcriptional regulation of terpene synthase genes in crops.</p>