ACC deaminase from Pseudomonas fluorescens mediated saline resistance in groundnut (Arachis hypogea) plants.
OBJECTIVE
To study the effect of 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase from Pseudomonas fluorescens against saline stress under in vitro and field conditions in groundnut (Arachis hypogea) plants.


RESULTS
Four plant growth-promoting rhizobacteria (PGPR) strains were used in this study to evaluate their efficacy in groundnut plants against saline stress under in vitro. Among the four PGPR strains used, Ps. fluorescens strain TDK1 showed greater performance in improving the plant growth parameters of groundnut seedlings in vitro. PCR amplification using Pseudomonas-specific 16S-23S rRNA internal transcribed spacers (ITS) primers revealed that all the four strains belonged to the group of fluorescent pseudomonads. ITS region of Ps. fluorescens strain TDK1 was cloned and sequenced. ACC deaminase activity using biochemical and molecular (PCR) analysis revealed that among all the four strains, Ps. fluorescens strain TDK1 showed greater amount of ACC deaminase activity and positive reaction to PCR amplification. ACC deaminase gene from Ps. fluorescens strain TDK1 was isolated, cloned and sequenced. Pseudomonas bioformulations were developed and they were tested in groundnut plants under saline-affected soils. The results indicated the superior performance by Ps. fluorescens strain TDK1 possessing ACC deaminase activity in improving yield parameters in groundnut plants despite salinity.


CONCLUSIONS
Pseudomonas fluorescens strain TDK1 possessing ACC deaminase activity enhanced the saline resistance in groundnut plants, which in turn resulted in increased yield when compared with the groundnuts treated with Pseudomonas strains not having ACC deaminase activity.


CONCLUSIONS
The promising role of ACC deaminase from Ps. fluorescens strain TDK1 in alleviating saline stress has been concluded in groundnut plants. This study will be useful for exploiting the activity of ACC deaminase from microbial strains against various biotic and abiotic stresses wherever ACC accumulated as precursor for ethylene biosynthesis.
Saravanakumar
D
D
Department of Plant Pathology, Centre for Plant Protection Studies, Tamil Nadu Agricultural University, Coimbatore 641003, Tamil Nadu, India. agrisara@rediffmail.com
Samiyappan
R
R
D010367:Arachis / Q000254:growth & development / Q000382:microbiology*; D019755:Carbon-Carbon Lyases; D010937:Plant Growth Regulators / Q000096:biosynthesis / Q000502:physiology*; D011551:Pseudomonas fluorescens / Q000302:isolation & purification / Q000502:physiology*; D012965:Sodium Chloride / Q000494:pharmacology*; D012988:Soil Microbiology
D010937:Plant Growth Regulators; D012965:Sodium Chloride; C033634:1-aminocyclopropane-1-carboxylate deaminase; D019755:Carbon-Carbon Lyases