On July 16, kouyanjun’s research team of China Rice Research Institute and Tao Zeng, a researcher from the school of agriculture of Zhejiang University, published a paper entitled”the addition” in the journal New Phytologistnal PRC2 subunit and Sin3 histone deacetylase complex are required for the normal distribution of H3K27me3 occupancy and transcriptioThe research paper”nal silencing in Magnaporthe oryzae” revealed the regulation mechanism of heterochromatin distribution and transcriptional silencing maintenance mediated by Polycomb inhibitory complex 2 (PRC2) in Magnaporthe grisea, deepened the understanding of the pathogenic mechanism of Magnaporthe grisea, and also provided theoretical guidance for the prevention and control of Magnaporthe grisea.
Rice is one of the most important food crops in the world, especially in China. The rice yield reduction caused by panicle neck blast and knot blast caused by rice blast fungus is the most serious. According to the prediction data of the National Agricultural Technology Extension Center, the occurrence area of rice blast can reach 60million Mu times in 2022. Revealing the pathogenic mechanism of Magnaporthe grisea and mining important pathogenic factors as potential drug targets are of great significance for the prevention and control of Magnaporthe grisea disease.
The growth and development of higher organisms require appropriate genes to maintain transcriptional silencing. The trimethylation of lysine at position 27 of histone H3 catalyzed by PRC2 (H3K27me3) is an important post-translational modification to maintain transcriptional silencing. The team previously reported that the core subunit kmt6-suz12-eed of PRC2 complex in Magnaporthe grisea is necessary to maintain H3K27me3 mediated gene silencing. At the same time, the core subunit plays an important role in the growth and development of Magnaporthe grisea, the expression and regulation of effector proteins in response to environmental stress and pathogenesis. However, it is not clear how H3K27me3’s occupation on chromosomes is regulated. In addition, in higher animals and plants, Polycomb inhibitory complex 1 (PRC1) can promote chromatin agglutination and help PRC2 achieve stable inhibition of target genes. However, in fungi, there is a lack of PRC1. How PRC2 can achieve stable inhibition of target gene transcription needs to be further explored.
In this study, we identified the accessory subunit p55 of PRC2, and combined with chip SEQ and RNA SEQ methods, revealed the important role of p55 in the distribution of H3K27me3 on the chromosome and gene transcription silencing. Further research found that p55 interacted with SIN3 of histone deacetylation complex, and SIN3 participated in the distribution of H3K27me3 and the regulation of target gene transcription silencing, indicating that histone deacetylation and H3K27me3 can jointly promote the heterochromatization of occupied regions and assist PRC2 to achieve stable inhibition of target genes. This study elucidates a new mechanism for regulating the distribution of H3K27me3 and stably maintaining gene transcriptional silencing in fungi.
The research was supported by the National Natural Science Foundation of China, the special science and technology project of new agricultural variety breeding in Zhejiang Province and the national youth talent program. Graduate students Lin Chuyu and Wu Zhongling are the co first authors of this paper. Tao Zeng, a researcher at the College of agriculture of Zhejiang University, and Kou Yanjun, a researcher at the China Rice Research Institute are the co corresponding authors of this paper. Professor linfucheng of the Zhejiang Academy of Agricultural Sciences participated in the guidance of this study.