Scholarlink

Background and aims <p>Flavonoids produced by legumes play a crucial role in initiating and regulating nodulation, serving as key signaling molecules in the legume-<i>rhizobium</i> symbiosis. However, the specific roles of individual flavonoids in the symbiotic process of <i>Medicago truncatula</i> remain poorly understood.</p> Methods <p>Here, we performed transcriptomic and flavonoid metabolomic analyses of <i>Sinorhizobium meliloti</i> 1021 (<i>Sm</i>1021)-inoculated and mock-inoculated <i>M. truncatula</i> roots at 8&#xa0;hours post-inoculation (hpi) to investigate the early responses to rhizobial infection.</p> Results <p>Our results revealed that flavonoid biosynthesis pathways were significantly enriched in <i>Sm</i>1021-inoculated roots compared to mock-inoculated roots at 8&#xa0;hpi. Flavonoid metabolome profiling identified 98 differentially accumulated flavonoids between <i>Sm</i>1021-inoculated and mock-inoculated roots at 8&#xa0;hpi. Three key flavonoids (2,4,2′,4′-tetrahydroxy-3′-prenylchalcone, methylnissolin, and kaempferol) were identified based on high variable importance in projection (VIP) scores and network analysis. Notably, the isoflavone methylnissolin strongly induced the expression of key nodulation genes of <i>Sm</i>1021. Molecular docking analysis indicated that methylnissolin potentially bound to three NodD proteins of <i>Sm</i>1021. Co-inoculation of <i>Sm</i>1021 with methylnissolin promoted nodulation of <i>M. truncatula</i> under nitrogen-limited conditions.</p> Conclusion <p>This study provides the first evidence that methylnissolin acts as a crucial inducer of rhizobial nodulation genes, enhancing nitrogen fixation efficiency in <i>M. truncatula</i>. Our findings highlight the pivotal role of flavonoids, particularly isoflavones, in the regulation of the legume-<i>rhizobium</i> symbiotic process.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

An isoflavone from Medicago truncatula, methylnissolin, induces expression of Sinorhizobium meliloti nodulation genes

  • 期刊论文

  • 发表日期：

    2025年7月9日

查看全文
  • Yongrui Shen,
  • Qianqian Huang,
  • Ting Yin,
  • Hongyu Zhang,
  • Zijian Wu,
  • Gehong Wei,
  • Minxia Chou

摘要

Background and aims

Flavonoids produced by legumes play a crucial role in initiating and regulating nodulation, serving as key signaling molecules in the legume-rhizobium symbiosis. However, the specific roles of individual flavonoids in the symbiotic process of Medicago truncatula remain poorly understood.

Methods

Here, we performed transcriptomic and flavonoid metabolomic analyses of Sinorhizobium meliloti 1021 (Sm1021)-inoculated and mock-inoculated M. truncatula roots at 8 hours post-inoculation (hpi) to investigate the early responses to rhizobial infection.

Results

Our results revealed that flavonoid biosynthesis pathways were significantly enriched in Sm1021-inoculated roots compared to mock-inoculated roots at 8 hpi. Flavonoid metabolome profiling identified 98 differentially accumulated flavonoids between Sm1021-inoculated and mock-inoculated roots at 8 hpi. Three key flavonoids (2,4,2′,4′-tetrahydroxy-3′-prenylchalcone, methylnissolin, and kaempferol) were identified based on high variable importance in projection (VIP) scores and network analysis. Notably, the isoflavone methylnissolin strongly induced the expression of key nodulation genes of Sm1021. Molecular docking analysis indicated that methylnissolin potentially bound to three NodD proteins of Sm1021. Co-inoculation of Sm1021 with methylnissolin promoted nodulation of M. truncatula under nitrogen-limited conditions.

Conclusion

This study provides the first evidence that methylnissolin acts as a crucial inducer of rhizobial nodulation genes, enhancing nitrogen fixation efficiency in M. truncatula. Our findings highlight the pivotal role of flavonoids, particularly isoflavones, in the regulation of the legume-rhizobium symbiotic process.