A PLANT FLAVONE, LUTEOLIN, INDUCES EXPRESSION OF RHIZOBIUM-MELILOTI NODULATION GENES
A PLANT FLAVONE, LUTEOLIN, INDUCES EXPRESSION OF RHIZOBIUM-MELILOTI NODULATION GENES
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DOI：
10.1126/science.3738520
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发表时间：
1986-08-29
期刊：
影响因子：
56.9
通讯作者：
LONG, SR
中科院分区：
文献类型：
--
作者：
PETERS, NK;FROST, JW;LONG, SR
苜蓿根瘤菌与紫花苜蓿的共生关系导致了固氮根瘤的形成。苜蓿根瘤菌nodABC基因是皮层细胞分裂和根毛卷曲等早期宿主反应所必需的。苜蓿分泌物对根瘤ABC表达的诱导表明，在根瘤发育的早期阶段，宿主-共生体信号传导。从植物分泌物中分离出一种能诱导拟南芥ABC表达的分子，通过构建拟南芥ABC与lacZ的融合体来监测其诱导活性。通过紫外-可见吸收光谱、核磁共振氢谱和质谱分析，确定诱导物为3“，4，5，7-四羟基黄酮（毛地黄黄酮）。木犀草素是一种常见的植物次生代谢产物，在植物界中广泛存在，可能在根瘤发育过程中起着控制NAPABC表达的作用。黄酮的这种调节作用与某些黄酮作为防御化合物的功能形成对比。
The symbiotic interaction of Rhizobium meliloti and alfalfa results in the formation of nitrogen-fixing root nodules. Rhizobium meliloti nodABC genes are required for the early host responses of cortical cell divisions and root hair curling. The induction of nodABC expression by alfalfa exudates demonstrates host-symbiont signaling at an early stage in nodule development. The inducer molecule for nodABC expression was isolated from plant exudate by constructing a nodABC-lacZ fusion to monitor the inducing activity. From ultraviolet-visible absorption spectra, proton nuclear magnetic resonance, and mass spectrometry, the inducer was determined to be 3'',4,5,7-tetrahydroxyflavone (luteolin). Luteolin is a normal secondary plant metabolite found throughout the plant kingdom that may serve to control nodABC expression during nodule development. This regulatory role for a flavone contrasts with the function of some flavonoids as defense compounds.