Negative Phototropism of Chlorophytum comosum Roots and Their Mechanisms

作     者：CHEN Juan KONG Yu WANG Zhong CHENG Shuiyuan GUYunjie GAN Jie CHEN Peng 

作者机构：College of Life Science/Hubei Key Laboratory of Economic Forest Germplasm Improvement and Resources Comprehensive Utilization/Hubei Collaborative Innovation Center for the Exploitation of Dabie Mountains Featuring ResourcesHuanggang Normal University Key Laboratory of Crop Genetics and Physiology of Jiangsu Province/Postdoctoral Research Station of Biology of Yangzhou UniversityYangzhou University Shanghai Institute for Biological SciencesChinese Academy of Sciences 

出 版 物：《Horticultural Plant Journal》 (园艺学报（英文版）)

年 卷 期：2015年第1卷第1期

页      面：55-60页

学科分类：090706[农学-园林植物与观赏园艺] 0907[农学-林学] 09[农学] 

基　　金：supported by the Postdoctoral Fund of Jiangsu Province(Grant No.1402115C) Open Fund of Hubei Key Laboratory of Economic Forest Germplasm Improvement and Resources Comprehensive Utilization of Huanggang Normal University,China (Grant No.2013000503) Industry University Cooperation Fund of Huanggang Normal University,China (Grant No.2012025703) New Forestry Major Project of Jiangsu Province(Grant No.lysx201305) National Natural Science Foundation of China(Grant No.31270228) 

主　　题：Chlorophytum comosum root hydroponics negative phototropism mechanism 

摘      要：The aerial roots of Chlorophytum comosum were grown hydroponically,allowing us to study the performance and mechanism of negative phototropism. The results of this study were as follows. All the adventitious roots and their branch roots bent away from light with a maximum curvature of approximately 88.5°. Blue-violet light prominently induced negative phototropism while red light had no effect. The root cap was the site of photo perception. Roots with shaded or divested root caps exposed to unilateral light showed no negative phototropism,but resumed their original characteristics when the shade was removed or when new root caps grew. The curvature increased when the light intensity ranged 0–110 μmol·m^(-2)·s^(-1). The negative phototropism curvature could be promoted by exogenous CaCl_2 but was inhibited by exogenous LaCl_3; exogenous CaCl_2 could reduce the inhibitory effect of LaCl_3. Unilateral light induced the horizontal transport of IAA from the irradiated side to the shaded side,resulting in an unequal distribution of IAA in both the sides,leading to negative phototropism. The horizontal transport of IAA was promoted by exogenous Ca^(2+) but inhibited by exogenous La^(3+).