Physiological and Chitinase Gene Expression Responses of Male Zizania latifolia to Ustilago esculenta Infection

This study explored the effects of Ustilago esculenta inoculation on physiological responses (activities of defense and antioxidant enzymes) and chitinase gene expression in male Zizania latifolia "jiaobai" (without U. esculenta infection, with no galls, but normal flowering). Male jiaobai seedlings were injected at the five-leaf stage with U. esculenta suspension, and the impact on transcription of several genes encoding enzymes was examined. Compared with controls, expression of most enzymes was significantly different at 3 or 12 hours postinjection, and most ZlChi genes were involved in the response to U. esculenta inoculation. Fluorescence quantitative polymerase chain reaction results showed that U. esculenta was present in the roots of male jiaobai inoculated with U. esculenta at the shoot tips. Paraffin sections revealed many fungal hyphae in the roots at 15 d after inoculation, but few in controls. The results provide a basis for further study of the responses of male Z. latifolia to U. esculenta infection.