ABSTRACT
The genome of rice blast fungus (Magnaporthe oryzae) encodes 15 glycoside hydrolase 18 family chitinases. In this study, we characterized the function of an M. oryzae extracellular chitinase, MoChi1, and its interaction with a host protein, OsMBL1, a jacalin-related Mannose-Binding Lectin (MBL) in rice (Oryza sativa). Deletion of MoChi1 resulted in reduced aerial hyphal formation and reduced virulence in rice by activating the expression of defense-responsive genes. We confirmed MoChi1 interaction with rice OsMBL1 in vitro and in vivo. OsMBL1 was induced by pathogen-associated molecular patterns and M. oryzae infection. Overexpression of OsMBL1 led to activation of rice defense-responsive genes and a chitin-induced reactive oxygen species burst, thereby enhancing resistance to M. oryzae Knockdown of OsMBL1 enhances susceptibility of rice plants to M. oryzae Furthermore, MoChi1 suppressed chitin-induced reactive oxygen species in rice cells and competed with OsMBL1 for chitin binding. Taken together, our study reveals a mechanism in which MoChi1 targets a host lectin to suppress rice immunity.
Subject(s)
Chitinases/metabolism , Host-Pathogen Interactions , Magnaporthe/enzymology , Mannose-Binding Lectin/metabolism , Oryza/microbiology , Amino Acid Sequence , Chitin/metabolism , Conserved Sequence , Fungal Proteins/metabolism , Magnaporthe/growth & development , Oryza/metabolism , Pathogen-Associated Molecular Pattern Molecules/metabolism , Plant Proteins/metabolism , Reactive Oxygen Species/metabolismABSTRACT
OBJECTIVE: To compare the therapeutic effect of method for regulating the Governor Vessel and Conception Vessel as well as routine needling method. METHODS: Sixty-four cases of pseudobulbar palsy after stroke were randomly divided into an observation group and a control group, 32 cases in each group. The observation group was treated with regulating the Governor Vessel and Conception Vessel, Tiantu (CV 22) through to Danzhong (CV 17), Shanglianquan (Extra), Baihui (GV 20) through to Naohu (GV 17), Fengfu (GV 16) were selected; the control group was treated with routine needling method with acupoints Yamen (GV 15), Lianquan (CV 23), Tongli (HT 5), Guanchong (TE 1). Scores of Watian drinking water test were observed before and after treatment, and therapeutic effects of two groups were compared. RESULTS: The effective rate of 87.5% (28/32) in the observation group was superior to that of 65.6% (21/32) in the control group (P < 0.05). Scores of Watian drinking water test in both groups were significantly decreased after treatment (both P < 0.01), and the degree of the decrease in the observation group was superior to that of control group (P < 0.01). CONCLUSION: Regulating the Governor Vessel and Conception Vessel has a significant therapeutic effect for treatment of pseudobulbar palsy after stroke, and superior to that of routine needling.
