Jambois Anne, Ditengou Franck Anicet, Kawano Tomonori, Delbarre Alain, Lapeyrie Frédéric
Unité Mixte de Recherche INRA-UHP Interactions Arbres/Micro-organismes, Institut National de la Recherche Agronomique, F-54280 Champenoux, France.
Physiol Plant. 2004 Mar;120(3):501-508. doi: 10.1111/j.0031-9317.2004.00268.x.
The indole alkaloids brucine and yohimbine, just like hypaphorine, counteract indole-3-acetic acid (IAA) activity in seedling roots, root hairs and shoots, but do not appear to alter auxin transport in roots or in cultured cells. In roots, the interactions between IAA and these three alkaloids appear competitive and specific since these molecules interact with IAA but with neither 1-naphthaleneacetic acid (NAA) or 2,4-dichlorophenoxyacetic acid (2,4-D), two synthetic auxins. The data reported further support the hypothesis that hypaphorine brucine and yohimbine compete with IAA on some auxin-binding proteins likely to be auxin receptors and that 2,4-D and NAA are not always perceived by the same receptor as IAA or the same component of that receptor. At certain steps of plant development and in certain cells, endogenous indole alkaloids could be involved in IAA activity regulation together with other well-described mechanisms such as conjugation or degradation. Hypaphorine with other active indole alkaloids remaining to be identified, might be regarded as a new class of IAA antagonists.
吲哚生物碱马钱子碱和育亨宾，与下箴刺桐碱一样，会抵消吲哚 - 3 - 乙酸（IAA）在幼苗根、根毛和芽中的活性，但似乎不会改变生长素在根或培养细胞中的运输。在根中，IAA与这三种生物碱之间的相互作用似乎具有竞争性和特异性，因为这些分子与IAA相互作用，但与两种合成生长素1 - 萘乙酸（NAA）或2,4 - 二氯苯氧乙酸（2,4 - D）均无相互作用。所报道的数据进一步支持了以下假设：下箴刺桐碱、马钱子碱和育亨宾在一些可能是生长素受体的生长素结合蛋白上与IAA竞争，并且2,4 - D和NAA并不总是被与IAA相同的受体或该受体的相同组分所识别。在植物发育的某些阶段以及某些细胞中，内源性吲哚生物碱可能与其他已充分描述的机制（如结合或降解）一起参与IAA活性的调节。下箴刺桐碱与其他有待鉴定的活性吲哚生物碱一起，可能被视为一类新的IAA拮抗剂。
