Bioenergy and Biomaterial Research Center, Bioscience and Biotechnology Institute, Hunan University, Changsha 410082, China.
J Plant Physiol. 2010 May 15;167(8):670-3. doi: 10.1016/j.jplph.2009.12.003. Epub 2010 Feb 4.
Cryptochromes are blue-light photoreceptors that control many aspects of plant development. In this study, cryptochrome mutants of Arabidopsis were examined to assess the role of cryptchrome-1 (CRY1) in lateral roots growth. When grown in blue light for 12d, mutant seedlings (cry1) showed increased growth of lateral roots, while CRY1-overexpressing transgenic seedlings (CRY1ox) exhibited a marked decrease. Lateral roots growth of CRY1ox could be stimulated by auxin, but expression of PIN1 (efflux carrier of polar auxin transport) was strongly reduced. Contrary, the cry1 mutation showed the opposite effect, indicating that blue light and the auxin-signaling pathway interact in lateral roots growth of Arabidopsis. The free IAA content in CRY1ox roots was half of that in wild type and cry1 mutant roots. Moreover, the content of flavonoids (quercetin, kaempferol, isorhamnetin), which act as endogenous negative regulators of auxin transport, increased in CRY1ox seedlings. Taken together, these results suggest that Arabidopsis CRY1 restrains lateral roots growth by inhibiting auxin transport.
隐花色素是蓝光受体，控制着植物发育的许多方面。在这项研究中，研究了拟南芥的隐花色素突变体，以评估隐花色素-1（CRY1）在侧根生长中的作用。在蓝光下生长 12 天后，突变体幼苗（cry1）表现出侧根生长增加，而 CRY1 过表达转基因幼苗（CRY1ox）则表现出明显的减少。CRY1ox 的侧根生长可以被生长素刺激，但 PIN1（极性生长素运输的外排载体）的表达强烈降低。相反，cry1 突变显示出相反的效果，表明蓝光和生长素信号通路在拟南芥的侧根生长中相互作用。CRY1ox 根中的游离 IAA 含量是野生型和 cry1 突变体根中的一半。此外，在 CRY1ox 幼苗中，作为生长素运输的内源性负调节剂的类黄酮（槲皮素、山奈酚、异鼠李素）的含量增加。综上所述，这些结果表明，拟南芥 CRY1 通过抑制生长素运输来抑制侧根生长。
