Jiangsu Key Laboratory of Crop Genetics and Physiology/Co-Innovation Center of Modern Production Technology of Grain Crops, College of Horticulture and Plant Protection, Yangzhou University, Yangzhou, 225009, China.
Appl Microbiol Biotechnol. 2022 Jun;106(12):4737-4748. doi: 10.1007/s00253-022-11986-z. Epub 2022 Jun 7.
Plastic film mulching can increase crop yield and is widely used in agricultural production, but long-term mulching could adversely affect plant growth. To investigate the related mechanism, we studied the bacterial communities in different root-associated compartments of Paeonia ostii, a perennial oil crop, under polyethylene film mulching for three years by full-length 16S rDNA sequencing technology, and measured the soil physicochemical properties and enzyme activities. We found that enzyme activities and available nutrients in the soil tended to decrease after long-term mulching. Analysis of bacterial community composition revealed that the endosphere may be another potential source of the root-associated microbiome of P. ostii, and the rhizoplane plays a selective gating role in the enrichment processes for P. ostii microbiome assembly. Long-term mulching affected the abundance of dominant bacterial communities in different root-associated compartments and reduced the bacterial richness in the endosphere, but increased bacterial interactions in each compartment, as well as between different compartments. We speculate that this is mainly related to the decrease of litter content and the serious degradation of polyethylene film after long-term mulching, which resulted in microplastics and other harmful substances entering the soil. Our study further explained the reasons for the harm of long-term film mulching on plants to guide the rational use of plastic film. KEY POINTS: •Soil enzyme activities and available nutrients decreased after long-term mulching. •Mulching affected the dominant bacterial abundance in different root-associated compartments. •Mulching increased bacterial interactions among compartments.
塑料薄膜覆盖可以提高作物产量，在农业生产中广泛应用，但长期覆盖可能会对植物生长产生不利影响。为了研究相关机制，我们通过全长 16S rDNA 测序技术，研究了三年聚乙烯薄膜覆盖下的多年生油料作物牡丹根相关区室中的细菌群落，并测量了土壤理化性质和酶活性。我们发现，长期覆盖后，土壤酶活性和有效养分趋于下降。细菌群落组成分析表明，根内生菌可能是牡丹根相关微生物组的另一个潜在来源，而根际在牡丹内生菌组装的富集过程中起着选择性的门户作用。长期覆盖影响了不同根相关区室中优势细菌群落的丰度，降低了根内生菌的丰富度，但增加了每个区室以及不同区室之间的细菌相互作用。我们推测，这主要与长期覆盖后枯枝落叶含量的减少和聚乙烯薄膜的严重降解有关，导致微塑料和其他有害物质进入土壤。我们的研究进一步解释了长期覆膜对植物危害的原因，以指导合理使用塑料薄膜。
·长期覆盖后土壤酶活性和有效养分下降。
·覆盖影响不同根相关区室中优势细菌的丰度。
·覆盖增加了区室之间的细菌相互作用。
