Davies P J
Section of Genetics Development and Physiology, Division of Biological Sciences, Cornell University, Ithaca, New York 14850.
Plant Physiol. 1976 Feb;57(2):197-202. doi: 10.1104/pp.57.2.197.
The term "bound auxin" is herein used to describe auxin conjugates insoluble in organic solvents which dissolve indoleacetic acid (IAA) and its derivatives, but hydrolyzable by NaOH to release IAA. Bound auxin from pea stems was fractionated into water-soluble, water-insoluble/NaOH-hydrolyzable, and insoluble components. Formation of bound auxin commenced with 15 minutes of applying exogenous labeled IAA, and progressively increased in amount, relative to IAA uptake, over 6 hours. Formation was not restricted to any particular zone of the stem and occurred in both light- and dark-grown stems. A greater quantity of bound auxin was formed in light-grown stems, reaching 4.2 and 7.7%, of the IAA taken up, in the water-soluble and water-insoluble/NaOH-hydrolyzable fractions after 6 hours. The presence of sucrose, during either the IAA treatment or an aging pretreatment had no effect, though 6 hours aging did cause a subsequent increase in the water-insoluble fraction of the bound auxin. Bound auxin formation in light-grown stems was dependent on respiratory metabolism, being reduced by KCN. It was also reduced, compared to total uptake, by inhibitors of RNA, and protein synthesis (6-methylpurine and cycloheximide) but only when the inhibitors preceded auxin addition and were present for a 4-hour period. Addition of inhibitors following auxin had no effect, suggesting an early inductive effect of auxin on bound auxin formation. Inhibitors of cell elongation had no effect. Deoxyglucose, an inhibitor of glucan synthesis, had only a small effect on the water-soluble fraction. Bound auxin is an important auxin product in growing plants. Its function is unknown, but some possibilities are discussed.
术语“结合生长素”在此用于描述不溶于能溶解吲哚乙酸（IAA）及其衍生物的有机溶剂，但可被氢氧化钠水解以释放IAA的生长素共轭物。豌豆茎中的结合生长素被分离为水溶性、水不溶性/氢氧化钠可水解性和不溶性组分。结合生长素的形成在施加外源标记IAA 15分钟后开始，并相对于IAA的吸收量在6小时内逐渐增加。其形成不限于茎的任何特定区域，在光照和黑暗生长的茎中均会发生。在光照生长的茎中形成的结合生长素数量更多，6小时后，水溶性和水不溶性/氢氧化钠可水解组分中形成的结合生长素分别达到吸收的IAA的4.2%和7.7%。在IAA处理或老化预处理期间添加蔗糖没有影响，不过6小时的老化确实导致结合生长素的水不溶性组分随后增加。光照生长的茎中结合生长素的形成依赖于呼吸代谢，会被氰化钾降低。与总吸收量相比，它也会被RNA和蛋白质合成抑制剂（6-甲基嘌呤和环己酰亚胺）降低，但前提是抑制剂在生长素添加之前加入并存在4小时。在生长素添加之后添加抑制剂没有影响，这表明生长素对结合生长素的形成有早期诱导作用。细胞伸长抑制剂没有影响。葡聚糖合成抑制剂脱氧葡萄糖对水溶性组分只有很小的影响。结合生长素是生长中的植物中一种重要的生长素产物。其功能尚不清楚，但讨论了一些可能性。
