A coin with double sides? Phytophthora essential effector Avh238 has dual functions in cell death activation and plant immunity suppression
B. YANG (1), Q. Wang (2), M. Jing (3), B. Guo (3), H. Wang (3), W. Ye (3), Y. Wang (3), S. Dong (3), Y. Wang (3) (1) Nanjing Agricultural University, China; (2) Department of Botany and Plant Pathology, Oregon State University, U.S.A.; (3) Nanjing Agricultural University, China

Phytophthora pathogens secrete effectors to manipulate host innate immunity and thereby to facilitate infection. Avh238 is an RxLR effector that not contributes to the virulence of Phytophthora sojae but also triggers cell death in various plant species. To date, the detailed molecular basis of Avh238 functions is largely unknown. Here, we showed that transient expression of Avh238 in Nicotiana benthamiana revealed its nucleus and cytoplasm localization. Avh238-triggered cell death required its nuclear localization, but suppression of INF1-triggered plant cell death required its cytoplasmic localization. Furthermore, we combined a natural variation investigation together with large scale mutagenesis assay, resulting in identifying key residues that are required for both functions. Taken together, our results demonstrate that the cell death-inducing and cell-death suppression activity of Avh238 are uncoupled. This work uncovers that a conserved Phytophthora RxLR effector evolve to escape the host recognition but retain the host immunity-suppressing activity to enhance virulence in planta.

Abstract Number: P9-326
Session Type: Poster