Inoculation with Acetobacter diazotrophicus increases glucose and fructose content in shoots of Sorghum bicolor (L.) Moench

BASTIÁN F; RAPPARINI F; BARALDI R; BOTTINI R ; PICCOLI P

SYMBIOSIS

SPRINGER

Año: 1999 vol. 27 p. 147 - 156

0334-5114

This work analyzes the effect of inoculation with Acetobacter diazotrophicus and of applications of GA3 and IAA on total carbohydrates, sucrose, glucose and fructose in shoots of Sorghum bicolor. Sorghum seedlings grown in plastic pots with sand-vermiculite were inoculated with pure cultures of A. diazotrophicus strain PAL 5 or sterile water. Two days later, GA3, IAA and a combination of the two hormones were applied to the first leaf of no inoculated seedlings. After 30 days, shoot samples were extracted with 1% TCA, carbohydrates assessed by phenol reaction, and individual sugars (sucrose, glucose and fructose) measured by capillary gas chromatography-flame ionization detection (GC-FID). A. diazotrophicus showed effective in promoting total carbohydrate accumulation as well as GA3 and IAA, being the most effective treatment GA3 at 30 pmol.plant-1 dose. However, neither the inoculation with the bacterium nor the different concentration of hormones produced sucrose increase as assessed by GC-FID. Notwithstanding fructose and glucose levels were significantly augmented by A. diazotrophicus as compared to control and GA3 and IAA treatments, suggesting that the effect of the bacterium might be exerted throughout invertase stimulation