UV-A specific regulation of anthocyanin biosynthesis in red turnip, Brassica rapa L. subsp. rapa : UV-A mediated protein phosphorylation.

摘要

The swollen hypocotyls of the 'Tsuda' cultivar of red turnip [B. campestris var. rapa] exhibited sunlight dependent anthocyanin accumulation and chalcone synthase gene (CHS) expression. However, these same cellular responses were not observed in the cv. Yurugi-Akamaru. CHS expression was enhanced by repeating daily 6-hour exposures to sunlight in 'Tsuda'. Anthocyanin production was also induced by a 6-hour UV-A irradiation trial, after subsequent incubation in darkness for more than 15 h. The minimum length of UV-A exposure required was less than two hours. Phosphoprotein detection by western blotting showed that a 51-kDa protein was phosphorylated after 5 min. of UV-A exposure and its dephosphorylation was complete within 120 min. of the exposure.