Mutation of a Nucleotide-Binding Leucine-Rich Repeat Immune Receptor-Type Protein Disrupts Immunity to Bacterial Blight. Issue 3 (29th August 2019)

• Record Type: Journal Article
• Authors: Tang, Jiuyou; Wang, Yiqin; Yin, Wenchao; Dong, Guojun; Sun, Kai; Teng, Zhenfeng; Wu, Xujiang; Wang, Shimei; Qian, Yangwen; Pan, Xuebiao; Qian, Qian; Chu, Chengcai
• Is Part Of: Plant physiology. Volume 181:Issue 3(2019)
• Page Start: 1295
• Page End: 1313
• Publication Date: 2019-08-29
• Subjects: Plant physiology -- Periodicals; Botany -- Periodicals; Periodicals; Electronic journals; 571.2
• DOI: 10.1104/pp.19.00686
• Languages: English
• ISSNs: 0032-0889

Abstract

Abstract : A gain-of-function mutation in a nucleotide-binding leucine-rich repeat immune receptor-type protein suppresses pattern-triggered or effector-triggered immunity to Xanthomonas oryzae in rice. Abstract: Most characterized plant resistance proteins belong to the nucleotide-binding domain and Leu-rich repeat-containing (NLR) family. NLRs are present in an auto-inhibited state in the absence of specific pathogens, while gain-of-function mutations in NLRs usually cause autoimmunity. Here, we show that a gain-of-function mutation, weaker defense ( wed ), which caused a Phe-to-Leu substitution in the nucleotide-binding domain of a typical NLR in rice ( Oryza sativa ), led to enhanced susceptibility to Xanthomonas oryzae pv. Oryzae . The unexpected accumulation of salicylic acid (SA), along with downregulation of NONEXPRESSOR OF PR1 ( NPR1 ), in wed indicates the potential presence of a feedback regulation loop of SA biosynthesis in rice. Epistasis analyses illustrated that SA accumulation and the NLR-associated components RAR1, OsRac1, and PhyB are dispensable for the wed phenotypes. Intriguingly, besides pattern-triggered immunity, effector-triggered immunity conferred by different resistance proteins, including Xa3/Xa26, Xa4, and Xa21, was also disturbed by wed to a certain extent, indicating the existence of shared regulatory mechanisms for various defense systems. The identification of wed therefore provides a unique system for genetic dissection of shared immune signaling pathways activated by different types of immune receptors.