Journal of Pure and Applied MicrobiologyVol. 8 No. 6

Effect of Plant Growth Regulator GA3 and PIX on Cell Growth and Structure of Rhizobium fredii and Bradyrhizobium japonicum

Wenhao Chen1 , Dianfeng Zheng1*, Naijie Feng1, Tao Liu1, Weidong Wang2, Hui Wang3 and Yang Lin4

1Agronomy College of Heilongjiang Bayi Agricultural University, Daqing, Heilonjiang 163319, China. 2Life Science and Technology of Heilongjiang Bayi Agricultural University, Daqing, Heilonjiang 163319, China. 3College of Agronomy and Biotechnology/Center of Biomass Engineering, China Agricultural University, Beijing 100193, China. 4Dalian Sanyi Bioengineering Research Institutes, Dalian Sanyi Animal Medicine Co., Ltd, Dalian, Liaoning, 116036,?China.

Received on 11 November 2013 and accepted on 15 January 2014

 

ABSTRACT

A comparative study was conducted on the effects of different concentrations (10-1-10-6) of the plant growth regulator GA3 and PIX on the bacterial population, growth rate, pH, and microstructure of Rhizobium fredii (GIM 1.227) and Bradyrhizobium japonicum (GIM 1.94). The results showed that the bacterial population, growth rate, pH value and relative expression of nodA and nodD of R. fredii and B. japonicum were increased, accelerated, reduced and up-regulated respectively, when the GA3 concentration in the medium was 10-3; however, the bacterial population, growth rate, pH value and relative expression of nodA and nodD of R. fredii and B. japonicum were decreased, decelerated, increased and down-regulated respectively, when the PIX concentration in the medium was 10-2. The microstructure of Rhizobium was altered by the plant growth regulator.

Keywords : Rhizobium fredii, Bradyrhizobium japonicum, Plant growth regulators, character of Rhizobium, nod gene.