Phototropic stimulation induces the conversion of glucosinolate to phototropism-regulating substances of radish hypocotyls
Phototropic stimulation induces the conversion of glucosinolate to phototropism-regulating substances of radish hypocotyls
复制标题
DOI：
10.1016/s0031-9422(00)00080-7
复制
发表时间：
2000-06-01
期刊：
影响因子：
3.8
通讯作者：
Hasegawa, K
中科院分区：
文献类型：
--
作者：
Hasegawa, T;Yamada, K;Hasegawa, K
天然生长抑制剂萝卜素（3-（甲硫基）亚甲基2-吡咯烷硫酮的异构体）及其前体（4-甲硫基-3-丁烯基芥子油苷（MTBG）和4-甲硫基-3-丁烯基异硫氰酸酯（MTBI））在向光性弯曲期间萝卜下胚轴光照和阴影部分之间的分布使用物理化学测定法进行了分析。向光性刺激迅速降低MTBG含量，突然增加MTBI和萝卜素的含量在30分钟内发病后的单侧照明的照射的一半萝卜下胚轴。阴影部分的含量与深色对照相似。当MTBG、MTBI和萝卜素在内源水平上单侧施加到黄化的下胚轴时，MTBI和萝卜素引起下胚轴弯曲，但MTBG没有表现出活性。蓝色照明促进黑芥子酶（硫代葡萄糖苷酶）的活性，释放MTBI从MTBG，在下胚轴后10分钟。虽然在黑暗中的控制酶活性没有变化。这些结果表明，向光性刺激促进黑芥子酶活性在萝卜下胚轴的照明侧，从失活MTBG释放生物活性MTBI，同时产生生物活性萝卜素。(C)2000爱思唯尔科技有限公司版权所有。
The distribution of natural growth inhibitors, the raphanusanins (isomers of 3-(methylthio)methylene 2-pyrrolidinethione) and their precursors (4-methylthio-3-butenyl glucosinolate (MTBG) and 4-methylthio-3-butenyl isothiocyanate (MTBI)), between illuminated and shaded halves of radish hypocotyls during phototropic curvature was analyzed using a physicochemical assay. Phototropic stimulation rapidly decreased MTBG content, and abruptly increased contents of MTBI and raphanusanins in the illuminated halves of radish hypocotyls within 30 min after the onset of unilateral illumination. Content in the shaded halves was similar to that in dark controls. When MTBG, MTBI, and raphanusanins at endogenous levels were applied unilaterally to etiolated hypocotyls, MTBI and raphanusanins caused hypocotyls to bend but MTBG showed no activity. Blue illumination promoted myrosinase (thioglucosidase) activity, which releases MTBI from MTBG, in hypocotyls after 10 min. although enzyme activity in dark controls did not change. These results suggest that phototropic stimulation promotes myrosinase activity in the illuminated side of radish hypocotyls, releasing bioactive MTBI from inactive MTBG and simultaneously producing bioactive raphanusanins. (C) 2000 Elsevier Science Ltd. All rights reserved.