Biocontrol Activity and Induction of Systemic Resistance in Pepper by Compost Water Extracts Against Phytophthora capsici
Tóm tắt
We investigated the effects of water extracts of composts (CWE) from commercial compost facilities for controlling root and foliar infection of pepper plants by Phytophthora capsici. Among 47 CWE tested, CWE from composts Iljuk-3, Iljuk-7, Shinong-8, and Shinong-9 significantly (P < 0.05) inhibited zoospore germination, germ tube elongation, mycelial growth, and population of P. capsici. All selected CWE significantly (P < 0.05) reduced the disease incidence and severity in the seedling and plant assays compared with the controls. However, there were no significant differences in zoospore germination, disease incidence, and disease severity between treatments of untreated, autoclaved, and filtered CWE. In addition, CWE significantly (P < 0.05) suppressed leaf infection of P. capsici through induced systemic resistance (ISR) in plants root-drenched with CWE. The tested CWE enhanced the expression of the pathogenesis-related genes, CABPR1, CABGLU, CAChi2, CaPR-4, CAPO1, or CaPR-10 as well as β-1,3-glucanase, chitinase, and peroxidase activities, which resulted in enhanced plant defense against P. capsici in pepper plants. Moreover, the CWE enhanced the chemical and structural defenses of the plants, including H2O2 generation in the leaves and lignin accumulation in the stems. The CWE could also suppress other fungal pathogens (Colletotrichum coccodes in pepper leaves and C. orbiculare in cucumber leaves) through ISR; however, it failed to inhibit other bacterial pathogens (Xanthomonas campestris pv. vesicatoria in pepper leaves and Pseudomonas syringae pv. lachrymans in cucumber leaves). These results suggest that a heat-stable chemical(s) in the CWE can suppress root and foliar infection by P. capsici in pepper plants. In addition, these suppressions might result from direct inhibition of development and population of P. capsici for root infection, as well as indirect inhibition of foliar infection through ISR with broad-spectrum protection.
Từ khóa
Tài liệu tham khảo
Kim K. D., 2000, Plant Pathol. J., 16, 283
Lee, C.H. 2000. Changes of the chemical properties of organic byproduct fertilizers during the composting and effect of those particle size and bulk density on soil hydraulic conductivity. Ph.D. dissertation, Korea University, Seoul, Republic of Korea. (In Korean)
Lee C.-H., 2006, Korean J. Soil Sci. Fertil., 39, 224
Levene, H. 1960. Contributions to Probability and Statistics: Essays in Honor of Harold Hotelling. Stanford University Press, Stanford, CA, U.S.A.
McGuire R. G., 1986, Plant Dis., 67, 779
Ministry of Environment. 2008. The forth basic plan for recycling resources. Publication no. 11-1480000-000894-01, Kwacheon, Republic of Korea. (In Korean)