Phytophthora sojae and soybean isoflavones, a model to study zoospore chemotaxis

• We summarized recent studies on molecular mechanism of Phytophthora sojae zoospore chemotaxis to soybean isoflavones.
• Functions of two P. sojae genes, PsGK4 and PsGPA1, which control zoospore chemotaxis were compared in this article.
• Dual roles of soybean isoflavones in P. sojae and soybean interaction were described for the first time.

The ability of sensing the signals from hosts, aggregating, and searching for proper sites of invasion is crucial for many soil-borne plant pathogens. One of these is Phytophthora sojae that specifically infects soybean and causes severe yield loss. In the field P. sojae zoospores attracted to soybean exudates isoflavones is an essential step for early infection. Recent studies based on genome mining and gene silencing technologies have shown that this special zoospore behavior relies on G-protein mediated signaling pathways. This review is to summarize researches on P. sojae functional genomics related to G-protein signaling and briefly describe the molecular mechanism of P. sojae zoospore chemotaxis to root exudates, especially isoflavones.