Andreote Fernando D, Mendes Rodrigo, Dini-Andreote Francisco, Rossetto Priscilla B, Labate Carlos A, Pizzirani-Kleiner Aline A, van Elsas Jan Dirck, Azevedo João L, Araújo Welington L
Departamento de Genética, Escola Superior de Agricultura Luiz de Queiroz, Universidade de São Paulo, Piracicaba, São Paulo, Brazil.
Antonie Van Leeuwenhoek. 2008 May;93(4):415-24. doi: 10.1007/s10482-007-9219-6. Epub 2008 Jan 8.
The rhizosphere constitutes a complex niche that may be exploited by a wide variety of bacteria. Bacterium-plant interactions in this niche can be influenced by factors such as the expression of heterologous genes in the plant. The objective of this work was to describe the bacterial communities associated with the rhizosphere and rhizoplane regions of tobacco plants, and to compare communities from transgenic tobacco lines (CAB1, CAB2 and TRP) with those found in wild-type (WT) plants. Samples were collected at two stages of plant development, the vegetative and flowering stages (1 and 3 months after germination). The diversity of the culturable microbial community was assessed by isolation and further characterization of isolates by amplified ribosomal RNA gene restriction analysis (ARDRA) and 16S rRNA sequencing. These analyses revealed the presence of fairly common rhizosphere organisms with the main groups Alphaproteobacteria, Betaproteobacteria, Actinobacteria and Bacilli. Analysis of the total bacterial communities using PCR-DGGE (denaturing gradient gel electrophoresis) revealed that shifts in bacterial communities occurred during early plant development, but the reestablishment of original community structure was observed over time. The effects were smaller in rhizosphere than in rhizoplane samples, where selection of specific bacterial groups by the different plant lines was demonstrated. Clustering patterns and principal components analysis (PCA) were used to distinguish the plant lines according to the fingerprint of their associated bacterial communities. Bands differentially detected in plant lines were found to be affiliated with the genera Pantoea, Bacillus and Burkholderia in WT, CAB and TRP plants, respectively. The data revealed that, although rhizosphere/rhizoplane microbial communities can be affected by the cultivation of transgenic plants, soil resilience may be able to restore the original bacterial diversity after one cycle of plant cultivation.
根际构成了一个复杂的生态位，各种各样的细菌都可能利用这个生态位。在这个生态位中，细菌与植物的相互作用可能会受到诸如植物中异源基因表达等因素的影响。这项工作的目的是描述与烟草植物根际和根表区域相关的细菌群落，并将转基因烟草品系（CAB1、CAB2和TRP）的群落与野生型（WT）植物中的群落进行比较。在植物发育的两个阶段，即营养期和开花期（发芽后1个月和3个月）采集样本。通过分离以及利用核糖体RNA基因限制性分析（ARDRA）和16S rRNA测序对分离株进行进一步表征，评估了可培养微生物群落的多样性。这些分析揭示了根际中相当常见的微生物的存在，主要类群包括α-变形菌纲、β-变形菌纲、放线菌和芽孢杆菌。使用PCR-DGGE（变性梯度凝胶电泳）对总细菌群落进行分析表明，在植物发育早期细菌群落发生了变化，但随着时间的推移观察到原始群落结构得以重建。根际中的影响比根表样本中的小，在根表样本中不同植物品系对特定细菌类群有选择作用。聚类模式和主成分分析（PCA）用于根据其相关细菌群落的指纹图谱区分植物品系。发现在野生型、CAB和TRP植物中，在植物品系中差异检测到的条带分别与泛菌属、芽孢杆菌属和伯克霍尔德菌属相关。数据表明，虽然转基因植物的种植可能会影响根际/根表微生物群落，但经过一个植物种植周期后，土壤恢复力可能能够恢复原始细菌多样性。
