de Almeida Lopes K B, Carpentieri-Pipolo V, Oro T H, Stefani Pagliosa E, Degrassi G
Agronomy Department, Post Graduation Program in Agronomy, Londrina State University, Londrina, PR, Brazil.
Embrapa Trigo, Passo Fundo, RS, Brazil.
J Appl Microbiol. 2016 Mar;120(3):740-55. doi: 10.1111/jam.13046.
Assess the diversity of the culturable endophytic bacterial population associated with transgenic and nontransgenic soybean grown in field trial sites in Brazil and characterize them phenotypically and genotypically focusing on characteristics related to plant growth promotion.
Endophytic bacteria were isolated from roots, stems and leaves of soybean cultivars (nontransgenic (C) and glyphosate-resistant (GR) transgenic soybean), including the isogenic BRS133 and BRS245RR. Significant differences were observed in bacterial densities in relation to genotype and tissue from which the isolates were obtained. The highest number of bacteria was observed in roots and in GR soybean. Based on characteristics related to plant growth promotion, 54 strains were identified by partial 16S rRNA sequence analysis, with most of the isolates belonging to the species Enterobacter ludwigii and Variovorax paradoxus. Among the isolates, 44·4% were able to either produce indoleacetic acid (IAA) or solubilize phosphates, and 9·2% (all from GR soybean) presented both plant growth-promoting activities.
The results from this study indicate that the abundance of endophytic bacterial communities of soybean differs between cultivars and in general it was higher in the transgenic cultivars than in nontransgenic cultivars. BRS 245 RR exhibited no significant difference in abundance compared to nontransgenic BRS133. This suggests that the impact of the management used in the GR soybean fields was comparable with the impacts of some enviromental factors. However, the bacterial endophytes associated to GR and nontransgenic soybean were different. The soybean-associated bacteria showing characteristics related to plant growth promotion were identified as belonging to the species Pantoea agglomerans and Variovorax paradoxus.
Our study demonstrated differences concerning compostion of culturable endophytic bacterial population in nontransgenic and transgenic soybean.
评估巴西田间试验点种植的转基因和非转基因大豆中可培养内生细菌群体的多样性，并从表型和基因型方面对其进行特征分析，重点关注与植物生长促进相关的特征。
从大豆品种（非转基因（C）和抗草甘膦（GR）转基因大豆）的根、茎和叶中分离内生细菌，包括同基因的BRS133和BRS245RR。观察到细菌密度在基因型和分离菌株的组织方面存在显著差异。在根和GR大豆中观察到的细菌数量最多。基于与植物生长促进相关的特征，通过部分16S rRNA序列分析鉴定出54株菌株，其中大多数分离株属于路德维希肠杆菌和奇异贪噬菌。在分离株中，44.4%能够产生吲哚乙酸（IAA）或溶解磷酸盐，9.2%（均来自GR大豆）同时具有两种植物生长促进活性。
本研究结果表明，大豆内生细菌群落的丰度在不同品种间存在差异，总体上转基因品种中的丰度高于非转基因品种。与非转基因的BRS133相比，BRS 245 RR的丰度没有显著差异。这表明GR大豆田使用的管理措施的影响与一些环境因素的影响相当。然而，与GR和非转基因大豆相关的内生细菌不同。表现出与植物生长促进相关特征的大豆相关细菌被鉴定为属于成团泛菌和奇异贪噬菌。
我们的研究证明了非转基因和转基因大豆中可培养内生细菌群体组成的差异。
