College of Eco-environment Engineering, Guizhou Minzu University, The Karst Environmental Geological Hazard Prevention of Key Laboratory of State Ethnic Affairs Commission, Guiyang 550025, China.
College of Eco-environment Engineering, Guizhou Minzu University, The Karst Environmental Geological Hazard Prevention of Key Laboratory of State Ethnic Affairs Commission, Guiyang 550025, China.
Sci Total Environ. 2024 Nov 1;949:175015. doi: 10.1016/j.scitotenv.2024.175015. Epub 2024 Jul 26.
Plants exert a profound influence on their rhizosphere microbiome through the secretion of root exudates, thereby imparting critical effects on their growth and overall health. The results unveil that japonica rice showcases a remarkable augmentation in its antioxidative stress mechanisms under Cd stress. This augmentation is characterized by the sequestration of heavy metal ions within the root system and the prodigious secretion of a spectrum of flavonoids, including Quercetin, Luteolin, Apigenin, Kaempferide, and Sakuranetin. These flavonoids operate as formidable guardians, shielding the plant from oxidative damage instigated by Cd-induced stress. Furthermore, the metagenomic analyses divulge the transformative potential of flavonoids, as they induce profound alterations in the composition and structural dynamics of plant rhizosphere microbial communities. These alterations manifest through the recruitment of plant growth-promoting bacteria, effectively engineering a conducive milieu for japonica rice. In addition, our symbiotic network analysis discerns that flavonoid compounds significantly improved the positive correlations among dominant species within the rhizosphere of japonica rice. This, in turn, bolsters the stability and intricacy of the microenvironmental ecological network. KEGG functional analyses reveal a notable upregulation in the expression of flavonoid functional genes, specifically cadA, cznA, nccC, and czrB, alongside an array of transporters, encompassing RND, ABC, MIT, and P-ATPase. These molecular orchestrations distinctly demarcated the rhizosphere microbiome of japonica rice, markedly enhancing its tolerance to Cd-induced stress. These findings not only shed light on the establishment of Cd-resistant bacterial consortia in rice but also herald a promising avenue for the precise modulation of plant rhizosphere microbiomes, thereby fortifying the safety and efficiency of crop production.
植物通过分泌根分泌物对根际微生物组产生深远影响，从而对其生长和整体健康产生关键影响。结果表明，在 Cd 胁迫下，粳稻显著增强了其抗氧化应激机制。这种增强表现为重金属离子在根系内的螯合和大量黄酮类化合物的分泌，包括槲皮素、木犀草素、芹菜素、山奈酚和樱花素。这些类黄酮作为强大的保护者，保护植物免受 Cd 诱导的应激引起的氧化损伤。此外，宏基因组分析揭示了类黄酮的转化潜力，因为它们引起了植物根际微生物群落组成和结构动态的深刻变化。这些变化表现为植物促生菌的招募，有效地为粳稻营造了有利的环境。此外，我们的共生网络分析发现，类黄酮化合物显著改善了粳稻根际中优势种之间的正相关关系。这反过来又增强了微环境生态网络的稳定性和复杂性。KEGG 功能分析显示，类黄酮功能基因 cadA、cznA、nccC 和 czrB 的表达以及一系列转运蛋白（包括 RND、ABC、MIT 和 P-ATPase）显著上调。这些分子调控明显区分了粳稻的根际微生物组，显著提高了其对 Cd 诱导应激的耐受性。这些发现不仅揭示了在水稻中建立 Cd 抗性细菌联合体的方法，而且为精确调节植物根际微生物组提供了有希望的途径，从而增强了作物生产的安全性和效率。
