The New Zealand Institute for Plant & Food Research Ltd; Auckland, New Zealand.
Plant Signal Behav. 2013 Aug;8(8). doi: 10.4161/psb.25033. Epub 2013 May 24.
Plants produce a vast array of phenolic compounds which are essential for their survival on land. One major class of polyphenols are the flavonoids and their formation is dependent on the enzyme chalcone synthase (CHS). In a recent study we silenced the CHS genes of apple (Malus × domestica Borkh.) and observed a loss of pigmentation in the fruit skin, flowers and stems. More surprisingly, highly silenced lines were significantly reduced in size, with small leaves and shortened internode lengths. Chemical analysis also revealed that the transgenic shoots contained greatly reduced concentrations of flavonoids which are known to modulate auxin flow. An auxin transport study verified this, with an increased auxin transport in the CHS-silenced lines. Overall, these findings suggest that auxin transport in apple has adapted to take place in the presence of high endogenous concentrations of flavonoids. Removal of these compounds therefore results in abnormal auxin movement and a highly disrupted growth pattern.
植物产生大量的酚类化合物，这些化合物对它们在陆地上的生存至关重要。多酚的一大类是类黄酮，它们的形成依赖于查尔酮合酶（CHS）。在最近的一项研究中，我们沉默了苹果（Malus × domestica Borkh.）的 CHS 基因，观察到果实表皮、花朵和茎的色素沉着丧失。更令人惊讶的是，高度沉默的系显著缩小，叶子变小，节间长度缩短。化学分析还表明，转基因芽中类黄酮的浓度大大降低，而类黄酮已知可以调节生长素的流动。生长素运输研究证实了这一点，CHS 沉默系中的生长素运输增加。总的来说，这些发现表明，苹果中的生长素运输已经适应了在高内源性类黄酮浓度存在的情况下进行。因此，这些化合物的去除会导致异常的生长素运动和高度破坏的生长模式。
