A RAPID REGULATORY RESPONSE GOVERNING NODULATION IN SOYBEAN
A RAPID REGULATORY RESPONSE GOVERNING NODULATION IN SOYBEAN
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DOI：
10.1104/pp.73.2.286
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发表时间：
1983-01-01
期刊：
影响因子：
7.4
通讯作者：
BAUER, WD
中科院分区：
文献类型：
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作者：
PIERCE, M;BAUER, WD
大豆幼苗接种根瘤菌后，在比接种时最易结瘤的区域年轻10 - 15小时的根部区域，其初生根上生长的根瘤数显著减少。用根瘤菌在2个不同的时间（间隔15 h）接种大豆幼苗，研究了这种快速抑制根瘤菌的作用。利弗河日本根瘤菌细胞，而不是异源根瘤菌或同源细菌的UV杀死的细胞，能够引起快速的抑制反应。不同接种物浓度的结瘤反应表明，细菌剂量可能是超优的，导致减少结瘤和减少抑制结瘤。当R.在根的发育较年轻的区域中，根瘤形成的抑制程度与在根的较老的和最初最敏感的区域中形成的根瘤的数量相关。然而，如果第一次接种仅限于与最初最容易结瘤的区域的根细胞接触，则根的发育较年轻区域的结瘤受到的影响很小。快速的调节反应可能是一个重要的因素，有助于集群的根瘤在冠区域的大豆根在田间生长的植物和稀疏的根瘤通常观察到的年轻地区的根。
The number of nodules which develop on the primary root of soybean seedlings after inoculation with Rhizobium japonicum is substantially diminished in the region of the root developmentally 10-15 h younger than the region maximally susceptible to nodulation at the time of inoculation. This rapid inhibition of nodulation was investigated by inoculating soybean seedlings with rhizobia at 2 different times, 15 h apart. Living R. japonicum cells, but not heterologous rhizobia or UV-killed cells of the homologous bacterium, were capable of eliciting the rapid inhibitory response. Nodulation responses to varying inoculum concentrations showed that bacterial dosages could be superoptimal, resulting in reduced nodulation and reduced inhibition of nodulation. When suspensions of R. japonicum were dripped uniformly onto the root surfaces, the degree of inhibition of nodulation in developmentally younger regions of the root was correlated with the number of nodules formed in the older and initially most susceptible region of the root. Nodulation in the developmentally younger region of the root, however, was affected very little if the 1st inoculum was restricted to contact with root cells in the region initially most susceptible to nodulation. The rapid regulatory response may be an important factor contributing to the clustering of nodules in the crown region of soybean roots in field-grown plants and the sparse nodulation commonly observed in younger regions of the root.