Law D M, Davies P J
Section of Plant Biology, Plant Science Building, Cornell University, Ithaca, New York 14853.
Plant Physiol. 1990 Aug;93(4):1539-43. doi: 10.1104/pp.93.4.1539.
Free indole-3-acetic acid levels were measured by gas chromatography-mass spectrometry in three ultra-tall ;slender' Pisum sativum L. lines differing in gibberellin content. Measurements were made for apices and stem elongation zones of light-grown plants and values were compared with wild-type, dwarf, and nana phenotypes in which internode length is genetically regulated, purportedly via the gibberellin level. Indole-3-acetic acid levels of growing stems paralleled growth rates in all lines, and were high in all three slender genotypes. Growth was inhibited by p-chlorophenoxyisobutyric acid, demonstrating the requirement of auxin activity for stem elongation, and also by the ethylene precursor 1-aminocyclopropane-1-carboxylic acid. It is concluded that the slender phenotype may arise from constant activation of a gibberellin receptor or transduction chain event leading directly or indirectly to elevated levels of indole-3-acetic acid, and that increased indole-3-acetic acid levels are a significant factor in the promotion of stem elongation.
采用气相色谱-质谱联用技术测定了三种赤霉素含量不同的超高大“细长型”豌豆（Pisum sativum L.）品系中的游离吲哚-3-乙酸水平。对光照生长植物的顶端和茎伸长区进行了测量，并将测量值与野生型、矮化和矮生表型进行了比较，在这些表型中，节间长度据推测是通过赤霉素水平进行遗传调控的。所有品系中，生长茎的吲哚-3-乙酸水平与生长速率平行，并且在所有三种细长基因型中都很高。对氯苯氧异丁酸抑制了生长，这表明生长素活性是茎伸长所必需的，乙烯前体1-氨基环丙烷-1-羧酸也有此作用。得出的结论是，细长型表型可能源于赤霉素受体或转导链事件的持续激活，这直接或间接导致吲哚-3-乙酸水平升高，并且吲哚-3-乙酸水平升高是促进茎伸长的一个重要因素。
