Effects of Volatiles from Pseudomonas chlororaphis O6 on the Plasticity of Growth inArabidopsis thalina

다국어 초록 (Multilingual Abstract)

Plant health can be affected positively and negatively by microbial volatiles. In this study, we examined the effect of the growth medium for Pseudomonas chlororaphis 06, a probiotic root coonizer, on the production of volatiles that affect the growth of Arabidopsis thaliana. In an I-plate bioassay, volatiles from the wild-type P. chlororaphis cells grown on nutrient agar significantly inhibited the shoot and root growth of A. thaliana. Volatiles from the wild-type P. chlororaphis cells grown on Methyl Red Vogues Proskauer medium (MR-VP) agar increased root branching with a minor reduction in root elogation. These responses were absent with exposure to volatile hydrogen cyanide(HCN). HCN synthesis was terminated in one mutant via delection of HCN-biosynthetic gene, wheareas the second mutant lacked expression of the global regulator GacS. The volatiles of the wild-type P. chlororaphis of the gaS mutant grown on MR-VP agar increased the shoot mass. However, the responses differed for mutants of A. thaliana—one lacked the ethylene receptor, another lacked sensitivity to jasmonic acid, and the third was unable to accumulate salicyli acid. These results indicate that the production of volatiles is significantly affected by the growth media utilized for P. chlororapjos 06 and that their effects on plant growth are infulenced by plant defense signaling pathways.