Department of Environmental Science and Engineering & Medical Faculty, Kunming University of Science and Technology, Kunming, 650500, China.
Department of Stomatology, Yan'an Hospital Affiliated to Kunming Medical University, Kunming, 650031, China.
Microb Ecol. 2024 Oct 28;87(1):133. doi: 10.1007/s00248-024-02445-5.
Heavy metal (HM) contaminants are the emerging driving force for reshaping the microflora of plants by eradicating the non-tolerance and non-resistant microbes via their lethal effects. Seeds served as a prime source of ancestral microbial diversity hereditary transfer from generation to generation. However, the problem arises when they got exposed to metal contamination, does metal pollutant disrupt the delicate balance of microbial communities within seeds and lead to shifts in their microflora across generations. In this study, the endophytic community within Zea mays seeds was compared across three distinct regions in Yunnan province, China: a HM-contaminated site Ayika (AK), less-contaminated site Sanduoduo (SD), and a non-contaminated Site Dali (DL). High-throughput sequencing techniques were employed to analyze the microbial communities. A total of 492,177 high-quality reads for bacterial communities and 1,001,229 optimized sequences for fungal communities were obtained. These sequences were assigned to 502 and 239 operational taxonomic units (OTUs) for bacteria and fungi, respectively. A higher diversity was recorded in AK samples than in SD and DL. Microbial community structure analysis showed higher diversity and significant fluctuation in specific taxa abundance in the metal-polluted samples exhibiting higher response of microbial flora to HM. In AK samples, bacterial genera such as Gordonia and Burkholderia-Caballeronia-Paraburkholderia were dominant, while in SD Pseudomonas and Streptomyces were dominant. Among the fungal taxa, Fusarium, Saccharomycopsis, and Lecanicillium were prevalent in HM-contaminated sites. Our finding revealed the influential effect of HM contaminants on reshaping the seed microbiome of the Zea mays, showing both the resilience of certain important microbial taxa as well the shifts in the diversity in the contaminated and pristine conditions. The knowledge will benefit to develop effective soil remediation, reclamation, and crop management techniques, and eventually assisting in the extenuation of metal pollution's adverse effects on plant health and agricultural productivity.
重金属（HM）污染物是通过其致死作用根除非耐受和非抗性微生物，从而成为重塑植物微生物区系的新兴驱动力。种子是遗传传递祖先微生物多样性的主要来源。然而，当它们暴露于金属污染时，问题就出现了，金属污染物是否会破坏种子内微生物群落的微妙平衡，并导致其微生物群在代际间发生变化。在这项研究中，对来自中国云南省三个不同地区的玉米种子内生群落进行了比较：一个是重金属污染的 Ayika（AK），一个是污染较小的 Sanduoduo（SD），一个是非污染的 Dali（DL）。采用高通量测序技术分析微生物群落。共获得细菌群落 492177 条高质量读数和真菌群落 1001229 条优化序列。这些序列分别被分配给细菌和真菌的 502 和 239 个操作分类单元（OTUs）。AK 样本的多样性高于 SD 和 DL。微生物群落结构分析显示，在受金属污染的样品中，微生物群落的多样性更高，特定类群丰度的波动更大，表明微生物菌群对重金属的反应更高。在 AK 样本中，细菌属 Gordonia 和 Burkholderia-Caballeronia-Paraburkholderia 占优势，而在 SD 样本中，假单胞菌和链霉菌占优势。在真菌类群中，镰刀菌属、酿酒酵母属和毛壳菌属在受污染的地点更为普遍。我们的发现揭示了重金属污染物对玉米种子微生物组重塑的影响，表明某些重要微生物类群具有弹性，同时在污染和原始条件下多样性也发生了变化。这些知识将有助于开发有效的土壤修复、开垦和作物管理技术，最终有助于减轻金属污染对植物健康和农业生产力的不利影响。
