A new cell death regulatory factor for plants during pathogen infections

October 27, 2017

Taking the phospho-proteomic approach, a collaborative team of researchers from Okayama University, RIKEN CSRS and other organizations has identified a protein, PSIG1, in the model plant Arabidopsis thaliana that regulates cell death upon infection with bacterial and oomycete pathogens.

Plants are exposed to a huge variety of microbes in nature. It is estimated that crops that would feed 800 million people are lost annually due to pathogen infections. The development of disease resistance and protective technology for crops is a vital issue, as an increasing world population necessitates a stable increase in food production. Understanding the immune mechanisms that plants use against pathogens is essential for enhancing the disease resistance of crop plants. However, the molecular mechanisms of how plants optimize their immune responses to pathogens with different infection strategies remains unclear.

Focusing on phosphorylation, which regulates protein functions, the researchers searched for factors whose phosphorylation status was modified upon activation of the immune system. In order to allow the plant to deal with pathogens with different infection strategies, the newly identified PSIG1 regulates and optimizes the cell death induction associated with the immune response. Additionally, PSIG1 was found to interact with the RNA metabolism-regulating factor SMG7, suggesting that RNA metabolism may play an important role in controlling cell death when a plant is faced with a pathogen infection.

These findings are expected to not only deepen our understanding of plant immunity but also to contribute to the development of disease resistance technologies.

Original article: PLOS Genetics doi: 10.1371/journal.pgen.1007037; H. Matsui, Y. Nomura, M. Egusa, T. Hamada, G.-S. Hyon, H. Kaminaka, Y. Watanabe, T. Ueda, M. Trujillo, K. Shirasu, H. Nakagami,; "The GYF domain protein PSIG1 dampens the induction of cell death during plant-pathogen interactions".
Contact: Hirofumi Nakagami; Visiting Scientist; Plant Immunity Research Group