title: PsHint1, associated with the G-protein α subunit PsGPA1, is required for the chemotaxis and pathogenicity of Phytophthora sojae.
abstract: Zoospore chemotaxis to soybean isoflavones is essential in the early stages of infection by the oomycete pathogen Phytophthora sojae. Previously, we have identified a G-protein α subunit encoded by PsGPA1 which regulates the chemotaxis and pathogenicity of P. sojae. In the present study, we used affinity purification to identify PsGPA1-interacting proteins, including PsHint1, a histidine triad (HIT) domain-containing protein orthologous to human HIT nucleotide-binding protein 1 (HINT1). PsHint1 interacted with both the guanosine triphosphate (GTP)- and guanosine diphosphate (GDP)-bound forms of PsGPA1. An analysis of the gene-silenced transformants revealed that PsHint1 was involved in the chemotropic response of zoospores to the isoflavone daidzein. During interaction with a susceptible soybean cultivar, PsHint1-silenced transformants displayed significantly reduced infectious hyphal extension and caused a strong cell death in plants. In addition, the transformants displayed defective cyst germination, forming abnormal germ tubes that were highly branched and exhibited apical swelling. These results suggest that PsHint1 not only regulates chemotaxis by interacting with PsGPA1, but also participates in a Gα-independent pathway involved in the pathogenicity of P. sojae.
authors.affiliation: Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Chunhua
authors.initials: C
authors.lastname: Zhai
authors.affiliation: Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Chenlei
authors.initials: C
authors.lastname: Hua
authors.affiliation: Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Min
authors.initials: M
authors.lastname: Qiu
authors.affiliation: Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Yujuan
authors.initials: Y
authors.lastname: Hao
authors.affiliation: Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Pingping
authors.initials: P
authors.lastname: Nie
authors.affiliation: Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Wenwu
authors.initials: W
authors.lastname: Ye
authors.affiliation: Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Yuanchao
authors.initials: Y
authors.lastname: Wang
mesh_terms: D002633:Chemotaxis; D044385:GTP-Binding Protein alpha Subunits / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation; D020868:Gene Silencing; D025301:Hyphae / Q000254:growth & development; D010802:Phylogeny; D010838:Phytophthora / Q000166:cytology* / Q000235:genetics / Q000472:pathogenicity*; D013170:Spores / Q000502:physiology; D014170:Transformation, Genetic
chemical_list: D044385:GTP-Binding Protein alpha Subunits
keywords: G-protein α subunit; HIT domain-containing protein; chemotaxis; interacting proteins; oomycete pathogen Phytophthora sojae; pathogenicity