Oral: Fungal Pathogenicity
Magnaporthe oryzae zinc finger effector1 exploits rice HIRA/AS1/AS2 complex to alter plant development and increase disease susceptibility
Y. Chen (1), W. Liu (2), Q. Wang (3), Y. Yang (2) (1) Penn State Univeristy, U.S.A.; (2) Penn State Univeristy, U.S.A.; (3) Penn State Univerisy, U.S.A.
Rice blast, caused by Magnaporthe oryzae, is one of the most important rice diseases in the world. During the fungal infection, M. oryzae produces many effector proteins to manipulate rice cellular process and facilitate disease development. In this study, a C2H2 zinc finger effector1 (MoZFE1) protein was identified from M. oryzae and shown to enter rice cells. Overexpression of MoZFE1 in transgenic rice (MoZFE1-OX) was found to alter rice growth and development and increase disease susceptibility. RNA-seq analysis reveals suppressions of some development- and defense-related gene expressions in the MoZFE1-OX lines. Both in vitro and in vivo biochemical analyses demonstrate that MoZFE1 directly interacts with a histone chaperon HIRA and suppresses the AS2 gene expression. HIRA/AS1/AS2 is a conserved gene-silencing complex and plays a role during plant organogenesis. Lose of function mutants (rice hira, as1, and as2 lines created with CRISPR/Cas9) was shown to cause developmental and differentiation defects with some phenotypes similar to MoZFE1-OX lines. Our study suggests that MoZFE1 exploits rice HIRA/AS1/AS2 complex to alter host gene expression, thereby manipulating plant growth and development as well as defense response. Our findings will help elucidate the molecular mechanism of the rice-M. oryzae interaction and facilitate the development of new strategies to improve rice disease resistance and food security.