Abstract：
Microplastics (MPs), widely presented in cultivated soil, have caused serious stresses on crop growth. However, the mechanism by which MPs affect legumes and rhizobia symbiosis is still unclear. Here, peanut seedlings were inoculated with Bradyrhizobium zhanjiangense CCBAU 51778 and were grown in vermiculite with 3 %/5 % (w/w) addition of PVC (polyvinyl chloride)-MPs/PBAT (polybutylene adipate)-MPs. PVC-MPs and PBAT-MPs separately decreased nodule number by 33-100 % and 2.62-80.91 %. Transcriptome analysis showed that PVC-MPs affected more DEGs (differentially expressed genes) than PBAT-MPs, indicating PVC-MPs were more devastating for the symbiosis than PBAT-MPs. Functional annotation revealed that PVC-MPs and PBAT-MPs enriched DEGs related to biosynthesis pathways such as flavonoid, isoflavonoid, and phenylpropanoid, in peanut. And when the dose increased from 3 % to 5 %, PVC-MPs mainly enriched the pathways of starch and sucrose metabolism, alanine, aspartate and glutamate metabolism, diterpenoid biosynthesis, etc.; PBAT-MPs enriched cysteine and methionine metabolism, photosynthesis, MAPK signaling, and other pathways. These significantly enriched pathways functioned in reducing nodule number and promoting peanut tolerance to MPs stresses. This study reveals the effect of PVC-MPs and PBAT-MPs on peanut and rhizobium symbiosis, and provides new perspectives for legume production and environmental safety.
摘要：
微塑料（MPs），广泛存在于耕种土壤中，对作物生长造成了严重的压力。然而,MP影响豆科植物和根瘤菌共生的机制尚不清楚。这里,用缓生根瘤菌zhanjiangenseCCBAU51778接种花生幼苗，并在蛭石中生长，添加3％/5％（w/w）的PVC（聚氯乙烯）-MPs/PBAT（聚己二酸丁二醇酯）-MPs。PVC-MPs和PBAT-MPs分别降低结节数33-100％和2.62-80.91%。转录组分析表明，PVC-MPs比PBAT-MPs影响更多的DEG（差异表达基因），表明PVC-MPs比PBAT-MPs对共生更具破坏性。功能注释显示PVC-MPs和PBAT-MPs富集了与类黄酮等生物合成途径相关的DEGs,异黄酮，和类苯丙烷,花生。当剂量从3%增加到5%时，PVC-MPs主要丰富了淀粉和蔗糖的代谢途径,丙氨酸,天冬氨酸和谷氨酸代谢，二萜生物合成，等。；PBAT-MPs富含半胱氨酸和蛋氨酸代谢，光合作用,MAPK信号，和其他途径。这些显着富集的途径在减少结节数量和促进花生对MPs胁迫的耐受性方面起作用。这项研究揭示了PVC-MPs和PBAT-MPs对花生和根瘤菌共生的影响。为豆类生产和环境安全提供了新的视角。
