solation, screening and phylogenetic analysis of plant growth-promoting rhizobacteria (PGPR) containing ACC deaminase from Jatropha curcas L.

Abstract:

[Objective] In order to obtain plant growth promoting strains of production 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase, nitrogen fixation, phosphate solubilization, and production of indoleacetic acid and siderophore. [Methods] 98 rhizobacteria from Jatropha curcas L. were isolated by the method of grinding separation and 28 isolates were selected for the detection of plant growth promoting index of production ACC deaminase, nitrogen fixation, phosphate solubilization, and production of indoleacetic acid and siderophore. [Results] The results showed that 46% of the isolates produced ACC with the maximum ACC deaminase was 128.308 μmol α-KA/(mg·h), 68% of the isolates produced IAA, 54% had nitrogen fixation ability and 32% of them had phosphate solubilization ability. Some of the representative isolates were seleceted for the 16S rRNA gene sequencing and analyzing. The representative strains belonged to 8 different genera including Bacillus, Arthrobacter, Pseudomonas and Alcaligenes, with Bacillus as the predominant genus (50%). Phylogenetic analysis demonstrated that strain KLBMP 4817、KLBMP 4821 and KLBMP 4824 could be potential novel species of the genera Stenotrophomonas and Paenibacillus. [Conclusion] The rhizobacteria of Jatropha curcas L. in Panzhihua City contain a variety of bacteria as well as source of new taxa. Some of them had the ability of plant growth promoting. Among them, strain KLBMP 4804 (Bacillus) had the strongest ACC deaminase activity. Strain KLBMP 4820 (Bacillus) had the strongest ability of IAA production respectively.

Key words:ACC deaminase, Jatropha curcas L., PGPR, Growth promoting, Phylogenetic analysis