Abstract
Phosphorus (P) availability and salinity stress are two major constraints for agriculture productivity. A combination of salinity and P starvation is known to be more deleterious to plant health. Plant growth promoting rhizobacteria are known to ameliorate abiotic stress in plants by increasing the availability of different nutrients. However, interaction mechanisms of plant grown under salinity and P stress condition and effect of beneficial microbe for stress alleviation is still obscure. Earlier we reported the molecular insight of auxin producing, phosphate solubilising Pseudomonas putida MTCC 5279 (RAR) mediated plant growth promotion in Arabidopsis thaliana. In present study new trait of proline and phosphatase production of RAR and its impact on modulation of physiological phenomenon under phosphate starved-salinity stress condition in A. thaliana has been investigated. Different physiological and molecular determinants under RAR- A. thaliana interaction showed that auxin producing RAR shows tryptophan dependence for growth and proline production in ATP dependant manner under salinity stress. However, under P deprived conditions growth and proline production are independent of tryptophan. RAR mediated lateral root branching and root hair density through modulation of abscisic acid signalling was observed. Acidic phosphatase activity under P starved and salinity stress condition was majorly modulated along with ROS metabolism and expression of stress responsive/phosphate transporter genes. A strong correlation of different morpho-physiological factor with RAR + salt conditions, showed We concluded that enhanced adverse effect of salinity with unavailability of P was dampened in presence of P. putida MTCC 5279 (RAR) in A. thaliana, though more efficiently salinity stress conditions. Therefore, alleviation of combined stress of salinity induced phosphate nutrient deficiency by inoculation of beneficial microbe, P. putida MTCC 5279 offer good opportunities for enhancing the agricultural productivity.
Highlights
Phosphorus (P) availability and salinity stress are two major constraints for agriculture productivity
Plant growth and productivity is continually decreasing due to occurrence of many biotic and abiotic stresses[30]
The present study is based on the characterization of abiotic stress tolerant P-solubilising, auxin producing, and plant growth promoting P. putida MTCC 5279 (RAR)[29,32], for production of proline, phosphatase enzyme and P accumulation (Fig. 1; Supplementary Fig. S2A–C and S4A,B)
Summary
Phosphorus (P) availability and salinity stress are two major constraints for agriculture productivity. It has been reported as most serious factor for limiting the productivity of agricultural crops by 20%3,4 Numerous hostile effects such as osmotic stress, ion toxicity, hormonal imbalance and generation of reactive oxygen species are known to be induced by salinity stress in plants[5]. Salinity stress are known to limit the phosphorus (P) availability, uptake and transport in plants probably due to its precipitation with other cations and hindrance of the acidic phosphatase activity[6,7,8]. Plant growth-promoting bacteria of different traits such as phosphate solubilisation, auxin and proline production are known to improve plant growth via diverse mechanisms They are known to sustain biomass, photosynthesis and homeostasis of toxic ions under saline stress[17,18]. Enhanced uptake of P through AMF colonization by the involvement of different mechanisms such as secretion of acid and alkaline phosphatases, maintenance of polyphosphate concentration and expression of high affinity phosphate transporter genes has been reported earlier[23]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
