Grape and Persimmon Research Station, National Institute of Fruit Tree Science, National Agriculture and Food Research Organization, NARO, Akitsu 301-2, Higashi Hiroshima, Hiroshima 739-2494, Japan.
Planta. 2012 Oct;236(4):1067-80. doi: 10.1007/s00425-012-1650-x. Epub 2012 May 9.
Temperature and light are important environmental factors that affect flavonoid biosynthesis in grape berry skin. However, the interrelationships between temperature and light effects on flavonoid biosynthesis have not been fully elucidated at the molecular level. Here, we investigated the effects of temperature and light conditions on the biosynthesis of flavonoids (anthocyanins and flavonols) and the expression levels of related genes in an in vitro environmental experiment using detached grape berries. Sufficient anthocyanin accumulation in the grape skin was observed under a low temperature (15 °C) plus light treatment, whereas high temperature (35 °C) or dark treatment severely suppressed anthocyanin accumulation. This indicates that the accumulation of anthocyanins is dependent on both low temperature and light. qRT-PCR analysis showed that the responses of three MYB-related genes (VlMYBA1-3, VlMYBA1-2, and VlMYBA2) to temperature and light differed greatly even though the products of all three genes had the ability to regulate anthocyanin biosynthesis pathway genes. Furthermore, the expression levels of other MYB-related genes and many flavonoid biosynthesis pathway genes were regulated independently by temperature and light. We also found that temperature and light conditions affected the anthocyanin composition in the skin through the regulation of flavonoid biosynthesis pathway genes. Our results suggest that low temperature and light have a synergistic effect on the expression of genes in the flavonoid biosynthesis pathway. These findings provide new information about the relationships between environmental factors and flavonoid accumulation in grape berry skin.
温度和光照是影响葡萄果皮中类黄酮生物合成的重要环境因素。然而，在分子水平上，温度和光照对类黄酮生物合成的相互影响尚未完全阐明。在这里，我们通过离体葡萄浆果的环境实验，研究了温度和光照条件对类黄酮（花青素和类黄酮醇）生物合成以及相关基因表达水平的影响。在低温（15°C）加光处理下，葡萄皮中观察到足够的花青素积累，而高温（35°C）或黑暗处理严重抑制花青素积累。这表明花青素的积累既依赖于低温又依赖于光照。qRT-PCR 分析表明，即使这三种基因的产物都具有调节花青素生物合成途径基因的能力，但三种 MYB 相关基因（VlMYBA1-3、VlMYBA1-2 和 VlMYBA2）对温度和光照的反应差异很大。此外，其他 MYB 相关基因和许多类黄酮生物合成途径基因的表达水平受温度和光照的独立调节。我们还发现，温度和光照条件通过调节类黄酮生物合成途径基因影响果皮中的花青素组成。我们的研究结果表明，低温和光照对类黄酮生物合成途径中基因的表达具有协同作用。这些发现为环境因素与葡萄浆果皮中类黄酮积累之间的关系提供了新的信息。
