Canamero Roberto C, Bakrim Nadia, Bouly Jean-Pierre, Garay Alvaro, Dudkin Elizabeth E, Habricot Yvette, Ahmad Margaret
Université de Paris VI, PCMP, Casier 156, 4 Place Jussieu, 75005 Paris, France.
Planta. 2006 Oct;224(5):995-1003. doi: 10.1007/s00425-006-0280-6. Epub 2006 May 9.
Cryptochromes are blue-light receptors controlling multiple aspects of plant growth and development. They are flavoproteins with significant homology to photolyases, but instead of repairing DNA they function by transducing blue light energy into a signal that can be recognized by the cellular signaling machinery. Here we report the effect of cry1 and cry2 blue light receptors on primary root growth in Arabidopsis thaliana seedlings, through analysis of both cryptochrome-mutant and cryptochrome-overexpressing lines. Cry1 mutant seedlings show reduced root elongation in blue light while overexpressing seedlings show significantly increased elongation as compared to wild type controls. By contrast, the cry2 mutation has the opposite effect on root elongation growth as does cry1, demonstrating that cry1 and cry2 act antagonistically in this response pathway. The site of cryptochrome signal perception is within the shoot, and the inhibitor of auxin transport, 1-N-naphthylphthalamic acid, abolishes the differential effect of cryptochromes on root growth, suggesting the blue-light signal is transmitted from the shoot to the root by a mechanism that involves auxin. Primary root elongation in blue light may thereby involve interaction between cryptochrome and auxin signaling pathways.
隐花色素是控制植物生长和发育多个方面的蓝光受体。它们是与光裂合酶具有显著同源性的黄素蛋白，但不是修复DNA，而是通过将蓝光能量转化为细胞信号传导机制能够识别的信号来发挥作用。在这里，我们通过对隐花色素突变体和隐花色素过表达株系的分析，报告了cry1和cry2蓝光受体对拟南芥幼苗初生根生长的影响。与野生型对照相比，cry1突变体幼苗在蓝光下根伸长减少，而过表达幼苗的伸长显著增加。相比之下，cry2突变对根伸长生长的影响与cry1相反，表明cry1和cry2在该反应途径中起拮抗作用。隐花色素信号感知位点在地上部分，生长素运输抑制剂1-N-萘基邻苯二甲酸消除了隐花色素对根生长的差异影响，这表明蓝光信号通过涉及生长素的机制从地上部分传递到根部。因此，蓝光下的初生根伸长可能涉及隐花色素和生长素信号通路之间的相互作用。
