Coronatine-Induced Maize Defense against Gibberella Stalk Rot by Activating Antioxidants and Phytohormone Signaling

• Published in: Journal of fungi (Basel) Vol. 9; no. 12; p. 1155
• Main Authors: Liu, Mei, Sui, Yiping, Yu, Chunxin, Wang, Xuncheng, Zhang, Wei, Wang, Baomin, Yan, Jiye, Duan, Liusheng
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 30-11-2023
• Subjects: Amino acids; Antioxidants; Biosynthesis; Calcium-binding protein; co-expression network; Corn; Coronatine; Defense mechanisms; Disease; Disease resistance; Enzymatic activity; Enzymes; Ethylene; Extensin; Flavonoids; Genes; Gibberella; Gibberella stalk rot; Glutathione transferase; Glycosyltransferase; Hydrogen peroxide; Infections; Jasmonic acid; Leucine zipper proteins; Linolenic acid; maize; Metabolism; Metabolites; Metabolomics; Molecular modelling; Pathogens; Permease; Plant growth; Signal transduction; Stalk rot; Stomata; transcriptome; China; metabolomics; Gibberella stalk rot; coronatine; transcriptome; phytohormone signaling; flavonoid biosynthesis; maize; co-expression network
• ISSN: 2309-608X; 2309-608X
• DOI: 10.3390/jof9121155

One of the most destructive diseases,
stalk rot (GSR), caused by
, reduces maize yields significantly. An induced resistance response is a potent and cost-effective plant defense against pathogen attack. The functional counterpart of JAs, coronatine (COR), has attracted a lot of interest recently due to its ability to control plant growth and stimulate secondary metabolism. Although several studies have focused on COR as a plant immune elicitor to improve plant resistance to pathogens, the effectiveness and underlying mechanisms of the suppressive ability against COR to
.
in maize have been limited. We investigated the potential physiological and molecular mechanisms of COR in modulating maize resistance to
.
. COR treatment strongly enhanced disease resistance and promoted stomatal closure with H
O
accumulation, and 10 μg/mL was confirmed as the best concentration. COR treatment increased defense-related enzyme activity and decreased the malondialdehyde content with enhanced antioxidant enzyme activity. To identify candidate resistance genes and gain insight into the molecular mechanism of GSR resistance associated with COR, we integrated transcriptomic and metabolomic data to systemically explore the defense mechanisms of COR, and multiple hub genes were pinpointed using weighted gene correlation network analysis (WGCNA). We discovered 6 significant modules containing 10 candidate genes: WRKY transcription factor (LOC100279570), calcium-binding protein (LOC100382070), NBR1-like protein (LOC100275089), amino acid permease (LOC100382244), glutathione
-transferase (LOC541830), HXXXD-type acyl-transferase (LOC100191608), prolin-rich extensin-like receptor protein kinase (LOC100501564), AP2-like ethylene-responsive transcription factor (LOC100384380), basic leucine zipper (LOC100275351), and glycosyltransferase (LOC606486), which are highly correlated with the jasmonic acid-ethylene signaling pathway and antioxidants. In addition, a core set of metabolites, including alpha-linolenic acid metabolism and flavonoids biosynthesis linked to the hub genes, were identified. Taken together, our research revealed differentially expressed key genes and metabolites, as well as co-expression networks, associated with COR treatment of maize stems after
infection. In addition, COR-treated maize had higher JA (JA-Ile and Me-JA) levels. We postulated that COR plays a positive role in maize resistance to
.
by regulating antioxidant levels and the JA signaling pathway, and the flavonoid biosynthesis pathway is also involved in the resistance response against GSR.