A Dihydroflavonol-4-Reductase-Like Protein Interacts with NFR5 and Regulates Rhizobial Infection in Lotus japonicus
A Dihydroflavonol-4-Reductase-Like Protein Interacts with NFR5 and Regulates Rhizobial Infection in Lotus japonicus
复制标题
二氢黄酮醇 4 还原酶样蛋白与 NFR5 相互作用并调节百脉根根瘤菌感染
DOI：
10.1094/mpmi-04-18-0104-r
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发表时间：
2019-04-01
影响因子：
3.5
通讯作者：
Zhang, Zhongming
中科院分区：
文献类型：
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作者：
Duan, Liujian;Pei, Junqing;Zhang, Zhongming
在根瘤菌和豆科植物之间的几乎所有共生相互作用中，宿主类黄酮诱导的根瘤菌中Nod因子的合成是启动植物共生反应所必需的。在这项研究中，我们发现百脉根Nod因子受体5（LjNFR5）可能在与根瘤菌共生相互作用过程中直接调节类黄酮生物合成。酵母双杂交分析表明二氢黄酮醇 4 还原酶样蛋白 (LjDFL1) 与 LjNFR5 相互作用。还显示了 MtDFL1 和 MtNFP（分别与 LjDFL1 和 LjNFR5 同源的两种蒺藜苜蓿蛋白）之间的相互作用，表明这两种蛋白之间的相互作用可能在不同的豆类中保守。 LjDFL1在根毛和根尖表皮细胞中高表达。在根瘤菌处理后，莲花 ljdfl1 突变体和苜蓿 mtdfl1 突变体产生的感染丝 (IT) 明显少于野生型对照植物。此外，在暴露于根瘤菌后，过度表达LjDFL1的稳定转基因日本参植物的根比对照根形成更多的IT。这些数据表明 LjDFL1 是共生信号传导的正调节因子。然而，LjDFL1 的表达受到根瘤菌处理的抑制，表明负反馈环可能参与了日本乳杆菌共生反应的调节。
In almost all symbiotic interactions between rhizobia and leguminous plants, host flavonoid-induced synthesis of Nod factors in rhizobia is required to initiate symbiotic response in plants. In this study, we found that Lotus japonicus Nod factor receptor 5 (LjNFR5) might directly regulate flavonoid biosynthesis during symbiotic interaction with rhizobia. A yeast two-hybrid analysis revealed that a dihydroflavonol-4-reductase-like protein (LjDFL1) interacts with LjNFR5. The interaction between MtDFL1 and MtNFP, two Medicago truncatula proteins with homology to LjDFL1 and LjNFR5, respectively, was also shown, suggesting that interaction between these two proteins might be conserved in different legumes. LjDFL1 was highly expressed in root hairs and epidermal cells of root tips. Lotus ljdfl1 mutants and Medicago mtdfl1 mutants produced significantly fewer infection threads (ITs) than the wild-type control plants following rhizobial treatment. Furthermore, the roots of stable transgenic L. japonicus plants overexpressing LjDFL1 formed more ITs than control roots after exposure to rhizobia. These data indicated that LjDFL1 is a positive regulator of symbiotic signaling. However, the expression of LjDFL1 was suppressed by rhizobial treatment, suggesting that a negative feedback loop might be involved in regulation of the symbiotic response in L. japonicus.