Opposing effects of MYZUS PERSICAE‐INDUCED LIPASE 1 and jasmonic acid influence the outcome of Arabidopsis thaliana–Fusarium graminearum interaction

Abstract

Fusarium graminearum (Fg) is an important fungal pathogen of small grain cereals that can also infect Arabidopsis thaliana. In Arabidopsis, jasmonic acid (JA) signalling involving JASMONATE RESISTANT 1 (JAR1), which synthesizes JA‐isoleucine, a signalling form of JA, promotes susceptibility to Fg. Here we show that Arabidopsis MYZUS PERSICAE‐INDUCED LIPASE 1 (MPL1), via its influence on limiting JA accumulation, restricts Fg infection. MPL1 expression was up‐regulated in response to Fg infection, and MPL1‐OE plants, which overexpress MPL1, exhibited enhanced resistance against Fg. In comparison, disease severity was higher on the mpl1 mutant than the wild type. JA content was lower in MPL1‐OE and higher in mpl1 than in the wild type, indicating that MPL1 limits JA accumulation. Pharmacological experiments confirmed the importance of MPL1‐determined restriction of JA accumulation on curtailment of Fg infection. Methyl‐JA application attenuated the MPL1‐OE‐conferred resistance, while the JA biosynthesis inhibitor ibuprofen enhanced resistance in mpl1. Also, the JA biosynthesis‐defective opr3 mutant was epistatic to mpl1, resulting in enhanced resistance in mpl1 opr3 plants. In comparison, JAR1 was not essential for the mpl1‐conferred susceptibility to Fg. Considering that methyl‐JA promotes Fg growth in culture, we suggest that in part MPL1 curtails disease by limiting the availability of a plant‐derived Fg growth‐promoting factor.

Pectate Lyase from Fusarium sacchari Induces Plant Immune Responses and Contributes to Virulence

“…ROS accumulation was then observed using a microscope (Leica, Germany). To observe callose deposition, leaves were collected 48 h after inoculation, stained with 0.1% aniline blue, and examined under a fluorescence microscope (Zeiss, Germany) ( 48 ). Twelve leaves were used in each experiment.…”

“…To further explore the functions of the FsPL gene, the single-barreled particle delivery system ( 41 ) was used to overexpress FsPL in the leaves of maize B73, which is closely related to F. sacchari host sugarcane. The GUS gene, which encodes β-glucosidase, was used as a reporter, as GUS hydrolyzes 5-bromo-4-chloro-3-indole-β-glucosidase (X-Gluc) into a blue substrate in living cells only ( 48 ). The open reading frames (ORFs) of FsPL , FsPLΔsp , GUS , and BAX were inserted into separate BamHI/KpnI doubly digested pCAMBIA2300 vectors.…”

Editorial: Lipid metabolism and membrane structure in plant biotic interactions

“…JA is one of the better studied signaling oxylipin in plants, which depending on the pathogen contributes to disease resistance or susceptibility ( Yan and Xie, 2015 ). JA also promotes spore germination in case of Fusarium graminearum ( Alam et al., 2022 ). Oxylipins are also produced by phytopathogens and influence pathogen development and virulence ( Christensen and Kolomiets, 2011 ; Pohl and Kock, 2014 ).…”