Blue‐light‐induced PIN 3 polarization for root negative phototropic response in Arabidopsis

作者：Kun‐Xiao Zhang, Henghao Xu, Tingting Yuan, Liang Zhang, Ying‐Tang Lu · 发表于：The Plant Journal · 年份：2013 · DOI：10.1111/tpj.12298 · 被引用次数：67 · 研究领域：Light effects on plants、Plant Molecular Biology Research、Photosynthetic Processes and Mechanisms

Root negative phototropism is an important response in plants. Although blue light is known to mediate this response, the cellular and molecular mechanisms underlying root negative phototropism remain unclear. Here, we report that the auxin efflux carrier PIN-FORMED (PIN) 3 is involved in asymmetric auxin distribution and root negative phototropism. Unilateral blue-light illumination polarized PIN3 to the outer lateral membrane of columella cells at the illuminated root side, and increased auxin activity at the illuminated side of roots, where auxin promotes growth and causes roots bending away from the light source. Furthermore, root negative phototropic response and blue-light-induced PIN3 polarization were modulated by a brefeldin A-sensitive, GNOM-dependent, trafficking pathway and by phot1-regulated PINOID (PID)/PROTEIN PHOSPHATASE 2A (PP2A) activity. Our results indicate that blue-light-induced PIN3 polarization is needed for asymmetric auxin distribution during root negative phototropic response.