Microbial Safety Division, National Academy of Agricultural Science, Rural Development Administration (RDA), Suwon 441-707, Republic of Korea.
J Microbiol Biotechnol. 2011 Aug;21(8):777-90. doi: 10.4014/jmb.1101.01031.
To elucidate the biodiversity of plant growth-promoting rhizobacteria (PGPR) in Korea, 7,638 bacteria isolated from the rhizosphere of plant species growing in many different regions were screened. A large number of PGPR were identified by testing the ability of each isolate to promote the growth of cucumber seedlings. After redundant rhizobacteria were removed via amplified rDNA restriction analysis, 90 strains were finally selected as PGPR. On the basis of 16S ribosomal RNA sequences, 68 Gram-positive (76%) and 22 Gram-negative (24%) isolates were assigned to 21 genera and 47 species. Of these genera, Bacillus (32 species) made up the largest complement, followed by Paenibacillus (19) and Pseudomonas (11). Phylogenetic analysis showed that most of the Grampositive PGPR fell into two categories: low- and high- G+C (Actinobacteria) strains. The Gram-negative PGPR were distributed in three categories: alpha-proteobacteria, beta- proteobacteria, and gamma-proteobacteria. To our knowledge, this is the largest screening study designed to isolate diverse PGPR. The enlarged understanding of PGPR genetic diversity provided herein will expand the knowledge base regarding beneficial plant-microbe interactions. The outcome of this research may have a practical effect on crop production methodologies.
为了阐明韩国植物促生根际细菌（PGPR）的生物多样性，从生长在许多不同地区的植物物种的根际中筛选了 7638 株细菌。通过测试每个分离株促进黄瓜幼苗生长的能力，鉴定了大量的 PGPR。通过扩增 rDNA 限制性分析去除冗余根际细菌后，最终选择了 90 株作为 PGPR。基于 16S 核糖体 RNA 序列，将 68 株革兰氏阳性（76%）和 22 株革兰氏阴性（24%）分离株分配到 21 个属和 47 个种。在这些属中，芽孢杆菌（32 种）构成最大的组成部分，其次是类芽孢杆菌（19 种）和假单胞菌（11 种）。系统发育分析表明，大多数革兰氏阳性 PGPR 分为两类：低和高 G+C（放线菌）菌株。革兰氏阴性 PGPR 分布在三个类别：α-变形菌、β-变形菌和γ-变形菌。据我们所知，这是最大规模的分离多样化 PGPR 的筛选研究。本文提供的对 PGPR 遗传多样性的深入了解将扩展关于有益植物-微生物相互作用的知识库。这项研究的结果可能对作物生产方法产生实际影响。
