IAA极性运输的自动抑制及其在组织中的代谢

Autoinhibition of Polar IAA Transport and Its Metabolism in Explant of Pea Plant

用IAA处理豌豆植株“Y”形外植体主茎残端，抑制了3H-IAA在侧枝茎段中的极性运输，并导致该组织中游离3H-IAA与3H-IAA总量比值的减小和乙烯释放量的明显增加。用乙烯作用抑制剂Ag＋处理侧枝可显著提高侧枝茎段组织中游离3H-IAA的比值，但并未消除主茎切口施用的IAA对3H-IAA极性运输的抑制作用。试验结果表明，主茎切口上施用的IAA是通过直接抑制作用完成对3H－IAA极性运输的抑制的。

Y' form explant consisting of part of second internode (10 mm), part of lateral shoot (10 mm) and part of first internode(5 mm) was cut off from pea plant. Preapplication of IAA to the cut surface of the second internode inhibited the polar 3H-IAA transport in another side of the explant, resulted in decrease in percentage of free 3H-IAA to total 3H-IAA and increase in ethylene production in the tissues. Pretreatment with AgNO3 solution (1 mmol·L-1) on the lateral shoot could prevent from the decrease in the percentage of free 3H-IAA to total 3H-IAA in the tissue, but the inhibited 3H-IAA transport caused by application of IAA was not restored.