Ruppel N J, Hangarter R P, Kiss J Z
Department of Botany, Miami University, Oxford, Ohio 45056, USA.
Planta. 2001 Feb;212(3):424-30. doi: 10.1007/s004250000410.
The interaction between light and gravity is critical in determining the final form of a plant. For example, the competing activities of gravitropism and phototropism can determine the final orientation of a stem or root. The results reported here indicate that, in addition to the previously described blue-light-dependent negative phototropic response in roots, roots of Arahidopsis thaliana (L.) Heynh. display a previously unknown red-light-dependent positive phototropic response. Both phototropic responses in roots are considerably weaker than the graviresponse, which often masks phototropic curvature. However, through the use of mutant strains with impaired gravitropism, we were able to identify a red-light-dependent positive phototropic response in Arabidopsis roots. The red-induced positive phototropic response is considerably weaker than the blue-light response and is barely detectable in plants with a normal gravitropic response.
光与重力之间的相互作用对于决定植物的最终形态至关重要。例如，向地性和向光性的相互竞争活动可以决定茎或根的最终取向。此处报道的结果表明，除了先前描述的根中依赖蓝光的负向光性反应外，拟南芥（Arabidopsis thaliana (L.) Heynh.）的根还表现出一种先前未知的依赖红光的正向光性反应。根中的两种向光性反应都比重力反应弱得多，重力反应常常掩盖向光性弯曲。然而，通过使用向地性受损的突变株系，我们能够在拟南芥根中鉴定出依赖红光的正向光性反应。红光诱导的正向光性反应比蓝光反应弱得多，在具有正常向地性反应的植物中几乎检测不到。
