Chemotaxis and oospore formation in Phytophthora sojae are controlled by G‐protein‐coupled receptors with a phosphatidylinositol phosphate kinase domain. Issue 2 (13th March 2013)

• Record Type: Journal Article
• Authors: Yang, X.; Zhao, W.; Hua, C.; Zheng, X.; Jing, M.; Li, D.; Govers, F.; Meijer, H. J. G.; Wang, Y.
• Is Part Of: Molecular microbiology. Volume 88:Issue 2(2013)
• Page Start: 382
• Page End: 394
• Publication Date: 2013-03-13
• Subjects: Molecular microbiology -- Periodicals; 572.829
• DOI: 10.1111/mmi.12191
• Languages: English
• ISSNs: 0950-382X

Abstract

<abstract abstract-type="main"> <title>Summary</title> <p>G‐protein‐coupled receptors (GPCRs) are key cellular components that mediate extracellular signals into intracellular responses. Genome mining revealed that <italic>Phytophthora</italic> spp. have over 60 GPCR genes among which a prominent class of 12 encoding novel proteins with an N‐terminal GPCR domain fused to a C‐terminal phosphatidylinositol phosphate kinase (PIPK) domain. This study focuses on two GPCR‐PIPKs (GKs) in <italic>Phytophthora sojae</italic>. <italic>PsGK4</italic> and <italic>PsGK5</italic> are differentially expressed during the life cycle with the highest expression in cysts and during cyst germination, and at late infection stages. In <italic>P. sojae</italic> transformants that constitutively express RFP‐tagged <italic>PsGK4</italic> and <italic>PsGK5</italic>, the fusion proteins in hyphae reside in small, rapidly moving vesicular‐like structures. Functional analysis using gene silencing showed that <italic>PsGK4</italic><italic>‐</italic>silenced transformants displayed higher levels of encystment and a reduced cyst germination rate when compared with the recipient strain. Moreover, GK4 deficiency (or reduction) resulted in severe defects in zoospore chemotaxis towards isoflavones and soybean roots. In contrast, <italic>PsGK5</italic><italic>‐</italic>silenced transformants exhibited no obvious defects in asexual development but oospore production was severely impaired. Both, <italic>PsGK4</italic>‐ and <italic>PsGK5</italic>‐silenced transformants showed reduced pathogenicity. These results point to involvement of GKs in zoospore behaviour, chemotaxis and oospore development, and suggest that PsGK4 and PsGK5 each head independent signalling pathways.</p> </abstract>