Black spot disease is one of the most serious diseases in Asian pear cultivation, with the commercial cultivar Nijisseiki being susceptible. Ethylene is known to play major roles in regulating plant defense responses against various pathogens. We investigated the relationship between ethylene synthesis and black spot disease in ‘Nijisseiki’ pear leaves by treatment with an analog of ethylene and 1-methylcyclopropene (1-MCP), an inhibitor of ethylene action. Interestingly, both treatments enhanced black spot disease symptoms. Both treatments also increased ethylene production in accordance with disease symptoms through altered gene expression of ethylene biosynthetic enzymes, especially 1-aminocyclopropane-1-carboxylate (ACC) synthase genes (PpACS3 and 4). Chemical names used: 1-methylcyclopropene (1-MCP), 1-aminocyclopropane-1-carboxylate (ACC).
Akihiro Itai, Takaaki Igori, Naoko Fujita, Mayumi Egusa, Motoichiro Kodama, and Hideki Murayama
Akihiro Itai and Naoko Fujita
Japanese pear pathotype), scab, and fruit ethylene production ( Banno et al., 1999 ; Sassa et al., 1997 ; Takasaki et al., 2004 ; Terakami et al., 2006 ). Thus, these markers can be used for marker-assisted selection of these four traits. In conclusion