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Nuclear Localization of HopA1_Pss61 Is Required for Effector-Triggered Immunity.

ABSTRACT: Plant resistance proteins recognize cognate pathogen avirulence proteins (also named effectors) to implement the innate immune responses called effector-triggered immunity. Previously, we reported that hopA1 from Pseudomonas syringae pv. syringae strain 61 was identified as an avr gene for Arabidopsis thaliana. Using a forward genetic screen approach, we cloned a hopA1-specific TIR-NBS-LRR class disease resistance gene, RESISTANCE TO PSEUDOMONAS SYRINGAE6 (RPS6). Many resistance proteins indirectly recognize effectors, and RPS6 is thought to interact with HopA1_Pss61 indirectly by surveillance of an effector target. However, the involved target protein is currently unknown. Here, we show RPS6 is the only R protein that recognizes HopA1_Pss61 in Arabidopsis wild-type Col-0 accession. Both RPS6 and HopA1_Pss61 are co-localized to the nucleus and cytoplasm. HopA1_Pss61 is also distributed in plasma membrane and plasmodesmata. Interestingly, nuclear localization of HopA1_Pss61 is required to induce cell death as NES-HopA1_Pss61 suppresses the level of cell death in Nicotiana benthamiana. In addition, in planta expression of hopA1_Pss61 led to defense responses, such as a dwarf morphology, a cell death response, inhibition of bacterial growth, and increased accumulation of defense marker proteins in transgenic Arabidopsis. Functional characterization of HopA1_Pss61 and RPS6 will provide an important piece of the ETI puzzle.

SUBMITTER: Kang H

PROVIDER: S-EPMC8145104 | biostudies-literature |

REPOSITORIES: biostudies-literature

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