Molecular biological analysis of regulatory mechanism of fruit coloration by temperature.

以葡萄、苹果和番茄为试材，研究了温度和激素对果实生长和花青素合成的影响。结果表明，夜间低温抑制了葡萄花青素的积累，抑制了花青素合成相关基因的表达。即使在夜间高温下，ABA也诱导了这些基因的表达，与葡萄着色有关的F3、5、H基因的表达也受到了高温的抑制。结果表明，夜间低温和ABA对花色苷的积累起着重要作用。利用~&lt；13&gt；C标记的CO_2进行的研究表明，葡萄的夜间低温促进了光合作用产物向浆果的转运。ABA改变了叶片向其他器官的转运。这些结果表明，ABA和低温通过不同的途径影响番茄花青素的积累。为了阐明盐胁迫促进番茄糖积累的机制，研究了碳水化合物内流和淀粉的生物合成。盐分处理促进了发育前期淀粉的积累，成熟期则增加了可溶性淀粉的积累。~&lt；13&gt；C示踪分析表明，在盐度胁迫下，碳水化合物流入果实的量增加，成熟后不再发生。ADP葡萄糖焦磷酸酶催化淀粉生物合成的第一步，在盐胁迫下的果实发育早期，酶活性升高。定量RT-PCR分析表明：(1)AgPS1和agpL1基因在果实发育过程中均受盐胁迫的上调，(Ii)AgpL1基因在转录水平上受ABA、糖和渗透胁迫的特异调控，进一步阐明了温度和ABA在基因表达水平上对果实生长成熟的重要影响。

Effects of temperature and phytohormones on fruit growth and anthocyanin synthesis were investigated using grapes, apples and tomatoes. The results indicated that low night temperature inhibited anthocyanin accumulation and inhibit expression of genes involved in anthocyanin synthesis in grapes. ABA induced these gene expressions even under high night temperature, F3^$5^$H gene expression, which is involved in coloration of grapes, was inhibited by high temperature, too. From the result of this experiment, it was revealed that low night temperature and ABA play important roles on accumulation of anthocyanin. The research using ^<13>C labeled CO_2 revealed that translocation of photosynthate into berries is enhanced by low night temperature in grapes. Translocation from leaves to other organs was changed by ABA. These results suggest that ABA and low night temperature affect on anthocyanin accumulation through different way.To elucidate the mechanisms underlying the phenomenon in which salinity stress enhances sugar accumulation in tomatoes, carbohydrate influx and starch biosynthesis were investigated. Salinity treatment promoted starch accumulation in early developing stages whereas soluble increased in ripening. Tracer analysis with ^<13>C revealed that carbohydrate influx into the fruit elevated under Salinity sugars stress, and it no longer occurred after ripening. Enzymatic activity of ADP glucose pyroghosphorylase, which catalyzes the first key step for starch biosynthesis, increased in fruit during early developing stages under the salinity stress. Quantitative RT-PCR analysis showed (I) Agp Sl and agpLl genes were up-regulated by salinity stress in developing fruit, (ii) AgpLl was specifically regulated by ABA, sugar and osmotic stress at transcriptional level.From the results of these studies, it was clarifies that temperature and ABA play important roles for fruit growth and maturation in gene expression level.