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苷合成的影响。结果表明，夜间低温抑制了葡萄花色素苷的积累，抑制了花色素苷合成相关基因的表达。阿坝诱导这些基因的表达，即使在夜间高温下，F3 ^$5 ^$H基因的表达也受到高温的抑制。结果表明，夜间低温和阿坝对花青苷的积累起重要作用。利用~（13）<13>C标记的CO_2研究表明，夜间低温促进了光合产物向果实的转运。阿坝改变了叶片向其它器官的运输。这些结果表明阿坝和夜间低温通过不同途径影响番茄花色素苷的积累。为了阐明盐胁迫促进番茄糖积累的机制，本文从糖内流和淀粉合成两个方面进行了研究。盐处理促进了淀粉在发育前期的积累，而可溶性淀粉在成熟期增加。~（13）C示踪分析<13>表明，盐糖胁迫下，果实中的碳水化合物内流增加，成熟后不再发生。在盐胁迫下，果实发育早期，ADP葡萄糖焦磷酸化酶活性升高，这是淀粉合成的第一个关键步骤。定量RT-PCR分析表明，Agp Sl和agpLl基因在果实发育过程中受到盐胁迫的上调，AgpLl基因在转录水平上受到阿坝、糖和渗透胁迫的特异性调控，从基因表达水平上阐明了温度和阿坝对果实生长和成熟的重要调控作用。

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.