Molecular mechanism & structure — zooming in on plant immunity

Authors: Helm, Matthew; MARGETS, ALEXANDRA - INDIANA UNIVERSITY; RIMA, SHARMIN - AUSTRALIAN NATIONAL UNIVERSITY; CARTER, MORGAN - UNIVERSITY OF ARIZONA

Submitted to: Molecular Plant-Microbe Interactions
Publication Type: Review Article
Publication Acceptance Date: 9/6/2021
Publication Date: 12/7/2021
Citation: Helm, M.D., Margets, A., Rima, S., Carter, M.E. 2021. Molecular mechanism & structure — zooming in on plant immunity. Molecular Plant-Microbe Interactions. 12:1346-1349. https://doi.org/10.1094/MPMI-08-21-0208-MR.
DOI: https://doi.org/10.1094/MPMI-08-21-0208-MR

Interpretive Summary: Plants have a sophisticated immune system capable of detecting and conferring resistance to plant pathogens. The plant immune system is composed of resistance proteins whose function is to detect and subsequently trigger an immune reaction in response to microbe infection. During the infection process, pathogens secrete proteins into the plant host cell in order to “shut-off” the plant immune system, thereby promoting pathogen growth and disease. However, if the plant contains a resistance protein capable of recognizing the protein from the pathogen, it will trigger an immune response, culminating in robust resistance responses against the pathogen. Despite the critical role plant resistance proteins have in defending against pathogens, very little is known about how they activate plant immune responses. Here, we summarize the concerted effort by multiple laboratories to study the process in which plant resistance proteins work while raising new questions for future research.

Technical Abstract: The first of three International Society for Molecular Plant Microbe Interactions (IS-MPMI) eSymposia was convened on July 12-13, 2021, with the theme “Molecular Mechanism & Structure - Zooming in on Plant Immunity”. Hosted by Jian-Min Zhou (Beijing, China) and Jane Parker (Cologne, Germany), the eSymposium centered on “Top 10 Unanswered Questions in MPMI” number five: Does effector-triggered immunity (ETI) potentiate and restore pattern-triggered immunity (PTI) — or is there really a binary distinction between ETI and PTI? Yet, the field is fast moving and since the previous International Congress of IS-MPMI in 2019, substantial progress has been made in untangling the complex signalling underlying plant immunity, including a greater understanding of the structure and function of key proteins. A clear need emerged for the MPMI community to come together virtually to share new knowledge around plant immunity. Over the course of two synchronous, half-days of programming, participants from 32 countries attended two plenary sessions with engaging panel discussions and networked through interactive hours and poster break out rooms. In this report, we summarize the concerted effort by multiple laboratories to study the molecular mechanisms underlying ETI and PTI, highlighting the essential role of plant resistosomes in the formation of calcium channels during an immune response. We conclude our report by forming new questions about how overlapping signaling mechanisms are controlled.