Phosphorus deficiency in red clover promotes exudation of orobanchol, the signal for mycorrhizal symbionts and germination stimulant for root parasites
Phosphorus deficiency in red clover promotes exudation of orobanchol, the signal for mycorrhizal symbionts and germination stimulant for root parasites
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DOI：
10.1007/s00425-006-0410-1
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发表时间：
2007-01
期刊：
影响因子：
4.3
通讯作者：
K. Yoneyama;K. Yoneyama;Y. Takeuchi;H. Sekimoto
中科院分区：
文献类型：
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作者：
K. Yoneyama;K. Yoneyama;Y. Takeuchi;H. Sekimoto
植物来源的倍半萜类植物内酯曾被认为是根寄生植物的萌发刺激剂，最近被确定为诱导菌丝分枝形态发生的分枝因子，这是丛枝菌根(AM)真菌识别寄主的关键步骤。在红三叶植物(Trifolium pratenseL.)中，作为AM真菌和根部寄生植物Orobanche minorSm的寄主，培养基中磷(P)的供应减少，但所检测的其他元素(N，K，Mg，Ca)的供应减少，显著促进了这种植物的根释放马立内酯orobancol。在红三叶植物中，根分泌物的促芽活性与根分泌物的促芽活性有很好的一致性。这表明，在缺磷条件下，植物根系不仅能吸引共生真菌，还能通过释放植物内酯来吸引根部寄生植物。这是第一个表明养分有效性影响根际共生和寄生相互作用的报告。
Plant derived sesquiterpene strigolactones, which have previously been characterized as germination stimulants for root parasitic plants, have recently been identified as the branching factors which induce hyphal branching morphogenesis, a critical step in host recognition by arbuscular mycorrhizal (AM) fungi. We show here that, in red clover plants (Trifolium pratenseL.), which is known as a host for both AM fungi and the root holoparasitic plantOrobanche minorSm., reduced supply of phosphorus (P) but not of other elements examined (N, K, Mg, Ca) in the culture medium significantly promotes the release of a strigolactone, orobanchol, by the roots of this plant. In red clover plants, the level of orobanchol exudation appeared to be regulated by P availability and was in good agreement with germination stimulation activity of the root exudates. This implies that under P deficiency, plant roots attract not only symbiotic fungi but also root parasitic plants through the release of strigolactones. This is the first report demonstrating that nutrient availability influences both symbiotic and parasitic interactions in the rhizosphere.