Genome-Wide Characterization of Jasmonates Signaling Components Reveals the Essential Role of ZmCOI1a-ZmJAZ15 Action Module in Regulating Maize Immunity to Gibberella Stalk Rot
Gibberella stalk rot (GSR) by <i>Fusarium graminearum</i> causes significant losses of maize production worldwide. Jasmonates (JAs) have been broadly known in regulating defense against pathogens through the homeostasis of active JAs and COI-JAZ-MYC function module. However, the function...
| Main Authors: | , , , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2021-01-01
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| Series: | International Journal of Molecular Sciences |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1422-0067/22/2/870 |
| Summary: | Gibberella stalk rot (GSR) by <i>Fusarium graminearum</i> causes significant losses of maize production worldwide. Jasmonates (JAs) have been broadly known in regulating defense against pathogens through the homeostasis of active JAs and COI-JAZ-MYC function module. However, the functions of different molecular species of JAs and COI-JAZ-MYC module in maize interactions with <i>Fusarium graminearum</i> and regulation of diverse metabolites remain unknown. In this study, we found that exogenous application of MeJA strongly enhanced resistance to GSR. RNA-seq analysis showed that MeJA activated multiple genes in JA pathways, which prompted us to perform a genome-wide screening of key JA signaling components in maize. Yeast Two-Hybrid, Split-Luciferase, and Pull-down assays revealed that the JA functional and structural mimic coronatine (COR) functions as an essential ligand to trigger the interaction between ZmCOIa and ZmJAZ15. By deploying CRISPR-cas9 knockout and <i>Mutator</i> insertional mutants, we demonstrated that <i>coi1a</i> mutant is more resistant, whereas <i>jaz15</i> mutant is more susceptible to GSR. Moreover, JA-deficient <i>opr7-5opr8-2</i> mutant displayed enhanced resistance to GSR compared to wild type. Together, these results provide strong evidence that <i>ZmJAZ15</i> plays a pivotal role, whereas <i>ZmCOIa</i> and endogenous JA itself might function as susceptibility factors, in maize immunity to GSR. |
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| ISSN: | 1661-6596 1422-0067 |