Inoculation Effect of Growth-promoting Rhizobacteria Bacillus cereus CLY07 of Taxus chinensis var. mairei

Plant growth-promoting rhizobacteria strain CLY07 was studied, which was isolated from the rhizosphere soil of Taxus chinensis var. mairei and could produce ACC(1−aminocyclopropane−1−carboxylic acid) deaminase. This strain was identified by morphology, physiology-biochemistry, and 16S rDNA sequence analysis. Some of plant growth promoting characteristics such as 1−Amino Cyclopropan−1−Carboxylate(ACC) deaminase production, phosphate solubilizing capacity, production of auxin(IAA) and siderophore were evaluated. The ACC Deaminase Gene(acds) of strain CLY07 was cloned. A derivative of this strain, labeled with GFP, was also used to study the colonization of its hosts by pouring to the root surface of T. chinensis var. mairei. The effect of inoculation with this strain on the seedlings in pots was carried out. The results showed strain CLY07 was identified as Bacillus cereus, which could produce IAA and siderophore, showed phosphorus-solubilizing ability and salt tolerance. The full-length acds gene of strain CLY07 is 996 bp. This strain can colonize stably in the rhizosphere and root surface for long periods of time. At first, the number of the labelled cells rised, then decreased, and finally tended to be stable; Moreover, strain CLY07 can promote remarkably the seedling growth and nutrient metabolism of T. chinensis var. mairei.