caa a22 4500 467890781 CHVBK 20180406152748.0 cr unu---uuuuu 170328e20060601xx s 000 0 eng 10.1007/s10327-005-0262-8 doi (NATIONALLICENCE)springer-10.1007/s10327-005-0262-8 Detoxification of α-tomatine by tomato pathogens Alternaria alternata tomato pathotype and Corynespora cassiicola and its role in infection [Elektronische Daten] [Kumiko Oka, Akiko Okubo, Motoichiro Kodama, Hiroshi Otani] In tomato plants, α-tomatine, a steroidal glycoalkaloid saponin, inhibits fungal growth. Tomato pathogens that produce host-specific toxins, Alternaria alternata tomato pathotype causing Alternaria stem canker and Corynespora cassiicola causing Corynespora target spot, were investigated for sensitivity to α-tomatine. Although spore germination of A. alternata pathogenic and nonpathogenic to tomato and of C. cassiicola pathogenic to tomato was not affected by 0.1 mM α-tomatine, spore germination of C. cassiicola nonpathogenic to tomato was significantly inhibited. This result showed that A. alternata, regardless of its pathogenicity, and only the C. cassiicola pathogenic to tomato are resistant to α-tomatine. Germinating spores of A. alternata and C. cassiicola resistant to α-tomatine detoxified α-tomatine by degrading it to a less polar product. After inoculation of tomato leaves, spores of A. alternata and C. cassiicola nonpathogenic to tomato germinated and formed appressoria, but did not form infection hyphae in host tissues. When a host-specific toxin (CCT-toxin) produced by C. cassiicola pathogenic to tomato was added to nonpathogenic spores, colonization within leaves was observed in A. alternata, but not in C. cassiicola. On the other hand, when spores of C. cassiicola nonpathogenic to tomato were suspended in spore germination fluid of nonpathogenic A. alternata with α-tomatine detoxification activity, the fungus could be induced to colonize leaves in the presence of CCT-toxin. These results indicate that A. alternata tomato pathotype and C. cassiicola pathogenic to tomato detoxify α-tomatine during infection and that this detoxification is essential for host colonization by pathogens that produce host-specific toxins. The Phytopathological Society of Japan and Springer-Verlag Tokyo, 2006 Alternaria alternata nationallicence Corynespora cassiicola nationallicence Host-specific toxin nationallicence α-Tomatine nationallicence Detoxification nationallicence Oka Kumiko The United Graduate School of Agricultural Sciences, Tottori University, Tottori, Japan aut Okubo Akiko Faculty of Agriculture, Tottori University, 680-8553, Tottori, Japan aut Kodama Motoichiro Faculty of Agriculture, Tottori University, 680-8553, Tottori, Japan aut Otani Hiroshi Faculty of Agriculture, Tottori University, 680-8553, Tottori, Japan aut Journal of General Plant Pathology Springer-Verlag 72/3(2006-06-01), 152-158 1345-2630 72:3<152 2006 72 10327 https://doi.org/10.1007/s10327-005-0262-8 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10327-005-0262-8 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Oka Kumiko The United Graduate School of Agricultural Sciences, Tottori University, Tottori, Japan aut NATIONALLICENCE 700 1- Okubo Akiko Faculty of Agriculture, Tottori University, 680-8553, Tottori, Japan aut NATIONALLICENCE 700 1- Kodama Motoichiro Faculty of Agriculture, Tottori University, 680-8553, Tottori, Japan aut NATIONALLICENCE 700 1- Otani Hiroshi Faculty of Agriculture, Tottori University, 680-8553, Tottori, Japan aut NATIONALLICENCE 773 0- Journal of General Plant Pathology Springer-Verlag 72/3(2006-06-01), 152-158 1345-2630 72:3<152 2006 72 10327 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer