Viebahn Mareike, Doornbos Rogier, Wernars Karel, van Loon Leendert C, Smit Eric, Bakker Peter A H M
Section of Phytopathology, Faculty of Biology, Utrecht University, PO Box 80084, 3508 TB Utrecht, the Netherlands.
Environ Microbiol. 2005 Nov;7(11):1775-85. doi: 10.1111/j.1462-2920.2005.00783.x.
A long-term field experiment (1999-2002) was conducted to monitor effects on the indigenous microflora of Pseudomonas putida WCS358r and two transgenic derivatives constitutively producing phenazine-1-carboxylic acid (PCA) or 2,4-diacetylphloroglucinol (DAPG). The strains were introduced as seed coating on wheat into the same field plots each year. Rhizosphere populations of ascomycetes were analysed using denaturing gradient gel electrophoresis (DGGE). To evaluate the significance of changes caused by the genetically modified microorganisms (GMMs), they were compared with effects caused by a crop rotation from wheat to potato. In the first year, only the combination of both GMMs caused a significant shift in the ascomycete community. After the repeated introductions this effect was no longer evident. However, cropping potato significantly affected the ascomycete community. This effect persisted into the next year when wheat was grown. Clone libraries were constructed from samples taken in 1999 and 2000, and sequence analysis indicated ascomycetes of common genera to be present. Most species occurred in low frequencies, distributed almost evenly in all treatments. However, in 1999 Microdochium occurred in relatively high frequencies, whereas in the following year no Microdochium species were detected. On the other hand, Fusarium-like organisms were low in 1999, and increased in 2000. Both the DGGE and the sequence analysis revealed that repeated introduction of P. putida WCS358r had no major effects on the ascomycete community in the wheat rhizosphere, but demonstrated a persistent difference between the rhizospheres of potato and wheat.
开展了一项长期田间试验（1999 - 2002年），以监测恶臭假单胞菌WCS358r及其两个组成型产生吩嗪 - 1 - 羧酸（PCA）或2,4 - 二乙酰基间苯三酚（DAPG）的转基因衍生物对本地微生物区系的影响。每年将这些菌株作为种子包衣施用于小麦，播种到相同的田间地块。使用变性梯度凝胶电泳（DGGE）分析子囊菌的根际种群。为了评估转基因微生物（GMM）引起的变化的显著性，将它们与从小麦到马铃薯的轮作所产生的影响进行比较。在第一年，只有两种GMM的组合导致子囊菌群落发生显著变化。在重复引入后，这种影响不再明显。然而，种植马铃薯显著影响了子囊菌群落。这种影响持续到次年种植小麦时。从1999年和2000年采集的样本构建了克隆文库，序列分析表明存在常见属的子囊菌。大多数物种出现的频率较低，在所有处理中分布几乎均匀。然而，在1999年，小丛壳菌出现的频率相对较高，而在次年未检测到小丛壳菌属的物种。另一方面，镰刀菌属样生物在1999年数量较少，而在2000年有所增加。DGGE和序列分析均表明，恶臭假单胞菌WCS358r的重复引入对小麦根际的子囊菌群落没有重大影响，但表明马铃薯和小麦根际之间存在持续差异。
