부산대학교 도서관

It has previously been found that turnip mosaic virus (TuMV) greatly suppresses anthocyanin accumulation (AA) in Brassica rapa leaves, and that such leaves become infected whilst anthocyanin-enriched leaves on the same plants are rarely infected. To clarify whether AA is a defense against TuMV, in this study we examined tissue-level patterns of spontaneous AA in relation to the cellular localization of a TuMV strain that expresses a yellow fluorescent protein. We found that TuMV infection was significantly blocked by AA, suggesting that it functions as a chemical barrier against TuMV. We next analysed changes in expression of genes related to anthocyanin biosynthesis in TuMV-infected leaves of Arabidopsis. TuMV also suppressed AA that is induced by high light in Arabidopsis, and this this suppression was mainly due to inhibited expression of anthocyanin late-biosynthesis genes (LBGs). Most positive transcription factors of LBGs were also down-regulated, while the negative regulator SPL15 was highly up-regulated. Cucumber mosaic virus (CMV) also moderately suppressed AA in Arabidopsis, but in a different manner. Since it appeared that anthocyanin-enriched leaves of Arabidopsis were resistant to TuMV but not CMV, our results suggested that the anthocyanin-associated resistance that we observed was specific to TuMV. [ABSTRACT FROM AUTHOR]