Characterization of 1-Aminocyclopropane-1-Carboxylate(ACC) Deaminase-Containing Pseudomonas spp.in the Rhizosphere of Salt-Stressed Canola  

作　　者：A.R.AKHGAR M.ARZANLOU P.A.H.M.BAKKER M.HAMIDPOUR 

机构地区：[1]Department of Soil Science,Vali-e-Asr University of Rafsanjan,Rafsanjan(Iran) [2]Department of Soil Science,University of Tabriz,Tabriz(Iran) [3]Department of Biology,Plant-Microbe Interactions,Utrecht University,Utrecht(Netherlands)

出　　处：《Pedosphere》2014年第4期461-468,共8页土壤圈（英文版）

摘　　要：When exposed to biotic or abiotic stress conditions, plants produce ethylene from its immediate precursor 1-aminocyclopropane-1- carboxylate （ACC）, leading to retarded root growth and senescence. Many plant growth-promoting rhizobacteria contain the enzyme ACC deaminase and this enzyme can cleave ACC to form a-ketobutyrate and ammonium, thereby lowering levels of ethylene. The aim of this study was to isolate and characterize ACC deaminase-producing bacteria from the rhizosphere of salt-stressed canola （Brassica napus L.）. Out of 105 random bacterial isolates, 15 were able to utilize ACC as the sole source of nitrogen. These 15 isolates were also positive for indole acetic acid （IAA） production. Phylogenetic analysis based on partial 16S rDNA sequences showed that all isolates belonged to fluorescent Pseudomonas spp. In the canola rhizosphere investigated in this study, Pseudomonas fluorescens was the dominant ACC deaminase-producing species. Cluster analysis based on BOX-AIR-based repetitive extragenic palindromic-polymerase chain reaction （BOX-PCR） patterns suggested a high degree of genetic variability in ACC deaminase-producing P. fluorescens strains. The presence of indigenous ACC-degrading bacteria in the rhizosphere of canola grown in saline soils indicates that these bacteria may contribute to salinity tolerance.When exposed to biotic or abiotic stress conditions,plants produce ethylene from its immediate precursor 1-aminocyclopropane-1-carboxylate(ACC),leading to retarded root growth and senescence.Many plant growth-promoting rhizobacteria contain the enzyme ACC deaminase and this enzyme can cleave ACC to form α-ketobutyrate and ammonium,thereby lowering levels of ethylene.The aim of this study was to isolate and characterize ACC deaminase-producing bacteria from the rhizosphere of salt-stressed canola(Brassica napus L.).Out of 105 random bacterial isolates,15 were able to utilize ACC as the sole source of nitrogen.These 15 isolates were also positive for indole acetic acid(IAA) production.Phylogenetic analysis based on partial 16 S rDNA sequences showed that all isolates belonged to fluorescent Pseudomonas spp.In the canola rhizosphere investigated in this study,Pseudomonas fluorescens was the dominant ACC deaminase-producing species.Cluster analysis based on BOX-A1R-based repetitive extragenic palindromic-polymerase chain reaction(BOX-PCR) patterns suggested a high degree of genetic variability in ACC deaminase-producing P.fluorescens strains.The presence of indigenous ACC-degrading bacteria in the rhizosphere of canola grown in saline soils indicates that these bacteria may contribute to salinity tolerance.

关 键 词：BOX-AiR-based repetitive extragenic palindromie-polymerase chain reaction （BOX-PCR） ethylene indole acetic acid phylogenetic analysis plant growth-promoting rhizobacteria （PGPR） Pseudomonas fluorescens 

分 类 号：S565.4[农业科学—作物学]