Functional characterization of the novel SPRYSEC effector family members from the potato cyst nematode Globodera rostochiensis
X. WANG (1), R. Cui (2), H. Yang (2), S. Chen (2) (1) USDA-ARS, U.S.A.; (2) Cornell University, U.S.A.; (3) Cornell University, U.S.A.

The two species of potato cyst nematodes (PCN) Globodera rostochiensis and G. pallida are internationally recognized quarantine pests that cause significant crop losses worldwide. These sedentary endoparasites secrete a repertoire of effector proteins originated from their esophageal gland cells into selected root cells to create a unique feeding structure that sustains the growth and development of the parasite. Previous studies indicated that both PCN species encode a large family of secreted SPRY domain-containing (SPRYSEC) proteins, in which a few members were shown to have a role in suppressing or eliciting plant immune responses. Based on database searches, we have identified and cloned a group of uncharacterized SPRYSEC genes (GrSPRYSEC) from G. rostochiensis. Sequence analysis revealed a highly polymorphic nature for some members. We then tested the functional properties of the cloned GrSPRYSEC genes using agrobacterium-mediated transient expression assays in Nicotiana benthamiana leaves. We have found that GrSPRYSEC effectors can be targeted to different plant cell structures including the nucleolus when expressed as a GFP-GUS fusion protein in N. benthamiana leaves. A majority of the GrSPRYSEC effectors are able to suppress the hypersensitive response induced by the Gpa2 resistance gene or ROS production triggered by the bacterial PAMP flg22, suggesting a critical role for some family members in host immunity suppression. However, the wide range of cellular targets observed in plant cells may suggest diverse functions of this novel SPRYSEC effector family in promoting nematode parasitism.

Abstract Number: P9-325
Session Type: Poster