The effects of G protein and cGMP on phytochrome mediated amaranthin biosynthesis in Amaranthus caudatus seedlings were studied. It was shown that G protein agonist cholera toxin induced amaranthin synthesis in darkne...The effects of G protein and cGMP on phytochrome mediated amaranthin biosynthesis in Amaranthus caudatus seedlings were studied. It was shown that G protein agonist cholera toxin induced amaranthin synthesis in darkness, whereas G protein antagonist pertussis toxin inhibited red light induced amaranthin synthesis. Amaranthin synthesis was also induced by exogenous cGMP, while the amaranthin biosynthesis induced by cholera toxin, red light and exogenous cGMP was inhibited by genistein. LY 83583, an inhibitor of guanylyl cyclase, inhibited the amaranthin synthesis induced both by red light and cholera toxin, while it was not able to inhibit the amaranthin synthesis induced by exogenous cGMP. These results suggest that G protein, guanylyl cyclase and cGMP were the candidates in phytochrome signal transduction chain for red light induced amaranthin biosynthesis and the red light signal transduction chain might be as follows: red light→phytochrome→G protein→guanylyl cyclase→cGMP.展开更多
Light plays a critical role in the regulation of plant morphogenetic and physiologicalresponses. As one of the extracellular signals, light signa1 is first received by the plantcells, then it affects the physiological...Light plays a critical role in the regulation of plant morphogenetic and physiologicalresponses. As one of the extracellular signals, light signa1 is first received by the plantcells, then it affects the physiological and biochemical status of the cells and the expressionof genetic characters through signal transduction. Tong has pointed out that until recentlythere had been little progress in the intersteps between phytochrome activation and展开更多
文摘The effects of G protein and cGMP on phytochrome mediated amaranthin biosynthesis in Amaranthus caudatus seedlings were studied. It was shown that G protein agonist cholera toxin induced amaranthin synthesis in darkness, whereas G protein antagonist pertussis toxin inhibited red light induced amaranthin synthesis. Amaranthin synthesis was also induced by exogenous cGMP, while the amaranthin biosynthesis induced by cholera toxin, red light and exogenous cGMP was inhibited by genistein. LY 83583, an inhibitor of guanylyl cyclase, inhibited the amaranthin synthesis induced both by red light and cholera toxin, while it was not able to inhibit the amaranthin synthesis induced by exogenous cGMP. These results suggest that G protein, guanylyl cyclase and cGMP were the candidates in phytochrome signal transduction chain for red light induced amaranthin biosynthesis and the red light signal transduction chain might be as follows: red light→phytochrome→G protein→guanylyl cyclase→cGMP.
文摘Light plays a critical role in the regulation of plant morphogenetic and physiologicalresponses. As one of the extracellular signals, light signa1 is first received by the plantcells, then it affects the physiological and biochemical status of the cells and the expressionof genetic characters through signal transduction. Tong has pointed out that until recentlythere had been little progress in the intersteps between phytochrome activation and
