ZmMYC2s play important roles in maize responses to simulated herbivory and jasmonate

Abstract

Both herbivory and jasmonic acid (JA) activate the biosynthesis of defensive metabolites in maize, but the mechanism underlying this remains unclear. We generated maize mutants in which ZmMYC2a and ZmMYC2b, two transcription factor genes important in JA signaling, were individually or both knocked out. Genetic and biochemical analyses were used to elucidate the functions of ZmMYC2 proteins in the maize response to simulated herbivory and JA. Compared with the wild-type (WT) maize, the double mutant myc2ab was highly susceptible to insects, and the levels of benzoxazinoids and volatile terpenes, and the levels of their biosynthesis gene transcripts, were much lower in the mutants than in

A tau class glutathione S‐transferase in tea plant, CsGSTU45, facilitates tea plant susceptibility to Colletotrichum camelliae infection mediated by jasmonate signaling pathway

“…MYC2 modulates pathogen defense by binding to the promoters of target JA‐responsive genes (Kazan & Manners, 2013; Ma et al., 2023; Valea et al., 2022; Wild et al., 2012; Yang et al., 2023). The key cis ‐elements bound by MYC2, including the T/G‐box, G‐box, and E‐box, are always found in the promoters of target genes (Chini et al., 2009; Kazan & Manners, 2013; Zhang et al., 2018).…”

“…This is probably because MYC2 acts as both a transcriptional activator and a transcriptional repressor in the regulation of different aspects of JA signaling (Kazan & Manners, 2013). MYC2 modulates pathogen defense by binding to the promoters of target JA-responsive genes (Kazan & Manners, 2013;Ma et al, 2023;Valea et al, 2022;Wild et al, 2012;Yang et al, 2023). The key cis-elements bound by MYC2, including the T/G-box, G-box, and E-box, are always found in the promoters of target genes (Chini et al, 2009;Kazan & Manners, 2013;Zhang et al, 2018).…”

Striking a growth–defense balance: Stress regulators that function in maize development

“…For instance, mutations in the ABA biosynthetic gene Vp14 render plants sensitive to drought, leading to heightened water loss rates in detached leaves (Tan et al, 1997). The JA‐deficient double mutant opr7 opr8 and the JA‐insensitive double mutant Zmmyc2a Zmmyc2b display compromised immunity, with enhanced susceptibility to necrotrophic fungi and/or herbivorous insects (Yan et al, 2012; Ma et al, 2023). Similarly, the Zmacs2 Zmacs6 double mutant, which is deficient in ET biosynthesis, exhibits increased susceptibility to infection by the hemibiotrophic fungus Fusarium graminearum (Zhou et al, 2019).…”

“…The failure to abort pistil primordia in tassel florets leads to the tasselseed ( ts ) phenotype. Among the known JA‐related mutants associated with the ts phenotype, including ts2 , ts1 , opr7 opr8 , Ts5 , Silky3 ( Si3 ), and Zmmyc2a Zmmyc2b , the ts phenotypes of all mutants except Zmmyc2a Zmmyc2b are attributed to decreased JA levels, and their ts phenotypes can be rescued by exogenous JA application (DeLong et al, 1993; Acosta et al, 2009; Yan et al, 2012; Lunde et al, 2019; Luo et al, 2020; Wang et al, 2020; Ma et al, 2023). The lower JA levels in the ts1 , opr7 opr8 , and Ts5 mutants are readily explained by the notion that mutations affect critical enzymes involved in JA biosynthesis or metabolism.…”

Multiple variation patterns of terpene synthases in 26 maize genomes

“…The expression value (reads per kilobase of transcript, per million mapped reads; RPKM) and results of the differential expression analysis of control and maize samples fed upon by Ostrinia furnacalis were retrieved from the supplementary tables in the study by Guo et al [25]. And other RNA-seq data about maize treated with oral secretions (OS) of Mythimna separata were also download [26,27]. Low quality sequences were remove by fastp [28].…”