Combined Role of ACC Deaminase Producing Bacteria and Biochar on Cereals Productivity under Drought

Most of the cereal crops are widely cultivated to fulfil the humans food requirements.Under changing climate scenario,the intensity of drought stress is continuously increasing that is adversely affecting the growth and yield of cereal crops.Although the cereals can tolerate moderate drought to some extent,but mostly they are susceptible to severe drought stress.Higher biosynthesis of ethylene under drought stress has been reported.Many scientists observed that inoculation of 1-aminocyclopropane-1-carboxylate(ACC)deaminase producing plant growth promoting rhizobacteria(PGPR)is an efficacious tool to overcome this problem.These PGPR secrete ACC deaminase which cleavage the ACC into the compounds,other than ethylene.Furthermore,secretion of growth hormones also play imperative role in enhancing the growth of the cereals under limited availability of water.In addition,the use of biochar has also been recognized as another effective amendment to grant resistance against drought.Biochar application improves the soil physiochemical attributes i.e.,porosity,nutrients retention and water holding capacity which decrease the loss of water and increase its bioavailability.In recent era,the idea of coapplication of ACC deaminase producing PGPR and biochar is becoming popular which might be more efficient to use water under drought stress.The aim of current review is to combine the facts and understanding of this novel idea to grant maximum resistance to crops against drought stress.Some scientists have observed significant improvement in yield of cereal crops by combined use of ACC deaminase producing PGPR and biochar.However,more research is suggested for deep understanding of complex synergistic mechanism of ACC deaminase activity in combination with biochar.

Effect of Inoculation with Three Phytohormone Producers Phytobacteria with ACC Deaminase Activity on Root Length of Lens esculenta Seedlings

Plant-associated bacteria that inhabit the rhizosphere may influence the plant growth by their contribution to the endogenous pool of phytohormones and by the activity of ACC deaminase to decrease the ethylene concentration. The aim of this study was to analyse the root length growth by the promoting effect of indole acetic acid producers phytobacteria with ACC deaminase activity, on inoculated seeds of Lens esculenta as synergistic effect on root elongation. In this study, although the roots of L. esculenta seedlings do not show a significant promotion, these phytobacteria could be recommended to treat plants analyzing their added inoculum to increase plant biomass and retard the effect of ethylene on cultures supplied with Tryptophan and ACC.

Seed priming with Pseudomonas putida isolated from rhizosphere triggers innate resistance against Fusarium wilt in tomato through pathogenesis-related protein activation and phenylpropanoid pathway

Pathogenesis-related(PR)proteins are one of the major and preliminary proteins accumulated as a defense against biotic stress.This defense response can be induced by using beneficial rhizobacteria,which has been studied in various host-pathogen interactions.In the present study,eleven Pseudomonas isolates were assessed for their potential to ferment sorbitol,reduce nitrate,and produce mycolytic enzymes,1-aminocyclopropane-l-carboxylic acid(ACC)deaminase,phenazine antibiotics,and N-acyl homoserine lactones(AHLs).All isolates were tested against the host-specific pathogen Fusarium oxysporum MTCC1755 in tomato under greenhouse conditions,and shortlisted isolates were tested for their rhizosphere competence.In-vitro test results showed that the isolates were able to produce mycolytic enzymes,including protease,lipase,chitinase,cellulase,and amylase,and the antibiotic phenazine and were negative for pyoluteorin.All the isolates except two were positive for ACC deaminase production.Greenhouse results showed that the isolates M80,M96,and T109 significantly reduced symptoms of Fusarium wilt.Extended greenhouse tests under autoclaved and unautoclaved soil conditions showed that M80,M96,and T109 were excellent rhizosphere competitors and were identified as Pseudomonas putida.In brief,the defense-specific biochemical variations in the host could describe the improved defense against Fusarium wilt occurring in the primed plants.These three Pseudomonas strains could be used as potential biocontrol agents,along with their rhizosphere competence.