Laboratorio Nacional de Genómica para la Biodiversida, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, CP 36821 Irapuato, Mexico.
Plant Physiol. 2013 Jun;162(2):779-99. doi: 10.1104/pp.113.218214. Epub 2013 Apr 22.
Synchronized communication between gametophytic and sporophytic tissue is crucial for successful reproduction, and hormones seem to have a prominent role in it. Here, we studied the role of the Arabidopsis (Arabidopsis thaliana) cytochrome P450 CYP78A9 enzyme during reproductive development. First, controlled pollination experiments indicate that CYP78A9 responds to fertilization. Second, while CYP78A9 overexpression can uncouple fruit development from fertilization, the cyp78a8 cyp78a9 loss-of-function mutant has reduced seed set due to outer ovule integument development arrest, leading to female sterility. Moreover, CYP78A9 has a specific expression pattern in inner integuments in early steps of ovule development as well as in the funiculus, embryo, and integuments of developing seeds. CYP78A9 overexpression did not change the response to the known hormones involved in flower development and fruit set, and it did not seem to have much effect on the major known hormonal pathways. Furthermore, according to previous predictions, perturbations in the flavonol biosynthesis pathway were detected in cyp78a9, cyp78a8 cyp78a9, and empty siliques (es1-D) mutants. However, it appeared that they do not cause the observed phenotypes. In summary, these results add new insights into the role of CYP78A9 in plant reproduction and present, to our knowledge, the first characterization of metabolite differences between mutants in this gene family.
雌雄配子体之间的同步通讯对于成功繁殖至关重要，而激素似乎在其中起着重要作用。在这里，我们研究了拟南芥（Arabidopsis thaliana）细胞色素 P450 CYP78A9 酶在生殖发育过程中的作用。首先，控制授粉实验表明 CYP78A9 对受精有反应。其次，虽然 CYP78A9 的过表达可以使果实发育与受精分离，但 cyp78a8 cyp78a9 功能丧失突变体由于外珠被发育停滞而导致种子结实减少，导致雌性不育。此外，CYP78A9 在胚珠发育早期的内珠被以及珠柄、胚胎和发育种子的珠被中具有特异性表达模式。CYP78A9 的过表达并没有改变对涉及花发育和果实结实的已知激素的反应，并且似乎对主要的已知激素途径没有太大影响。此外，根据先前的预测，在 cyp78a9、cyp78a8 cyp78a9 和 empty siliques (es1-D) 突变体中检测到类黄酮生物合成途径的扰动。然而，似乎它们不会引起观察到的表型。总之，这些结果为 CYP78A9 在植物生殖中的作用提供了新的见解，并首次描述了该基因家族突变体之间代谢物差异的特征。
