Direct Estimation of Local pH Change at Infection Sites of Fungi in Potato Tubers.
Fungi can modify the pH in or around the infected site via alkalization or acidification, and pH monitoring may provide valuable information on host-fungus interactions. The objective of the present study was to examine the ability of two fungi, Colletotrichum coccodes and Helminthosporium solani, to modify the pH of potato tubers during artificial inoculation in situ. Both fungi cause blemishes on potato tubers, which downgrades tuber quality and yield. Direct visualization and estimation of pH changes near the inoculation area were achieved using pH indicators and image analysis. The results showed that the pH of the area infected by either fungus increased from potato native pH of approximately 6.0 to 7.4 to 8.0. By performing simple analysis of the images, it was also possible to derive the growth curve of each fungus and estimate the lag phase of the radial growth: 10 days for C. coccodes and 17 days H. solani. In addition, a distinctive halo (an edge area with increased pH) was observed only during the lag phase of H. solani infection. pH modulation is a major factor in pathogen-host interaction and the proposed method offers a simple and rapid way to monitor these changes.
First and second authors: Faculty of Civil and Environmental Engineering, Technion-Israel Institute of Technology. Haifa 32000, Israel; and third author: Department of Plant Pathology & Weed Research, Institute of Plant Protection, Agricultural Research Organization, Gilat Research Center, M.P. Negev 85280, Israel.
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First and second authors: Faculty of Civil and Environmental Engineering, Technion-Israel Institute of Technology. Haifa 32000, Israel; and third author: Department of Plant Pathology & Weed Research, Institute of Plant Protection, Agricultural Research Organization, Gilat Research Center, M.P. Negev 85280, Israel.
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First and second authors: Faculty of Civil and Environmental Engineering, Technion-Israel Institute of Technology. Haifa 32000, Israel; and third author: Department of Plant Pathology & Weed Research, Institute of Plant Protection, Agricultural Research Organization, Gilat Research Center, M.P. Negev 85280, Israel.
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Tsror Lahkim
D020231:Colletotrichum / Q000502:physiology*; D006375:Helminthosporium / Q000502:physiology*; D054884:Host-Pathogen Interactions; D006863:Hydrogen-Ion Concentration; D010935:Plant Diseases / Q000382:microbiology*; D035281:Plant Tubers / Q000737:chemistry / Q000166:cytology / Q000382:microbiology; D011198:Solanum tuberosum / Q000737:chemistry / Q000166:cytology / Q000382:microbiology*