Biological Science Research Laboratories, Kao Corporation, 2606 Ichikai, Haga, Tochigi 321-3497, Japan.
Safety Science Research Laboratories, Kao Corporation, 2606 Ichikai, Haga, Tochigi 321-3497, Japan.
J Agric Food Chem. 2024 Aug 21;72(33):18465-18477. doi: 10.1021/acs.jafc.4c03064. Epub 2024 Aug 7.
Legume plants form symbiotic relationships with rhizobia, which allow plants to utilize atmospheric nitrogen as a nutrient. This symbiosis is initiated by secretion of specific signaling metabolites from the roots, which induce the expression of genes in rhizobia. These metabolites are called gene inducers (NGIs), and various flavonoids have been found to act as NGIs. However, NGIs of chickpea, the second major pulse crop, remain elusive. We conducted untargeted metabolome analysis of chickpea root exudates to explore metabolites with increased secretion under nitrogen deficiency. Principal component (PC) analysis showed a clear difference between nitrogen deficiency and control, with PC1 alone accounting for 37.5% of the variance. The intensity of two features with the highest PC1 loading values significantly increased under nitrogen deficiency; two prominent peaks were identified as -methylated isoflavones, pratensein and biochanin A. RNA-seq analysis showed that they induce gene expression in the symbiont, suggesting that pratensein and biochanin A are chickpea NGIs. Pratensein applied concurrently with at sowing promoted chickpea nodulation. These results demonstrate that pratensein and biochanin A are chickpea NGIs, and pratensein can be useful for increasing nodulation efficiency in chickpea production.
豆科植物与根瘤菌形成共生关系，根瘤菌使植物能够将大气氮作为养分加以利用。这种共生关系是由根系分泌的特定信号代谢物引发的，这些代谢物诱导根瘤菌中基因的表达。这些代谢物被称为基因诱导物（NGIs），已发现多种类黄酮可作为 NGIs。然而，作为第二大主要豆类作物的鹰嘴豆的 NGIs 仍然难以捉摸。我们对鹰嘴豆根渗出物进行了非靶向代谢组学分析，以探索在氮缺乏下分泌增加的代谢物。主成分（PC）分析表明，氮缺乏与对照之间存在明显差异，仅 PC1 就占方差的 37.5%。在氮缺乏下，具有最高 PC1 加载值的两个特征的强度显著增加；两个突出的峰被鉴定为 -甲基化异黄酮，pratensein 和 biochanin A。RNA-seq 分析表明，它们诱导共生体中基因的表达，表明 pratensein 和 biochanin A 是鹰嘴豆的 NGIs。播种时同时施用 pratensein 和 可促进鹰嘴豆结瘤。这些结果表明，pratensein 和 biochanin A 是鹰嘴豆的 NGIs，而 pratensein 可用于提高鹰嘴豆生产中的结瘤效率。
