Maize Endophytic Microbial-communities And Their Synthetic Applications

Agricultural losses due to pests and diseases are estimated one third each year globally and soil-borne-pathogens alone cause 90% diseases in economically important crops.To attain food security,it is vital to increase the nutritional value of food and crop yield to feed the ever-growing population.Crop damage due to soil-borne-pathogens is the key concern while obtaining sustainable agriculture.Bio-control is the possible strategy to control pathogen invasion in crops by using inoculants that comprise of plant growth promoting bacteria(PGPB)without further environmental destruction and reliability on industrial products.Precisely,in this study endophytic microbial-community showed eminent beneficial functions as well,are the main players for plant health associated with their host and soil physical properties regulated the dynamic shift of microbial community.During the greenhouse experiment,it was found that different soil types contain variations in microbial-community associated with roots and leaves of the maize plant.In current study,Removing PCR(R-PCR)and 16 S r DNA gene amplification methods were used for the identification of the endophytes microbial-community from maize plant grown in different soil types.The R-PCR is one of the simple and cost-effective methods for generating differentially expressed genomic DNA fragments distinguishing the samples under comparison,established by our research group.Data analysis,identified 167 bacterial operational taxonomy units(OTUs)and unexpected 8 fungal OTUs by R-PCR,whereas,95 bacterial OTUs via 16 S r DNA sequencing from maize roots and leaves.The 95 OTUs presented as the endophytic bacterial strains,and these bacterial-strains were screened for antagonism potential against Rhizoctonia solani WH1.Out of them,17 strains inhibited the mycelium growth,further these strains were screened for in vitro compatibly test.Also,out of them,five strains were recognized as 1.Bacillus atrophaeus strain MR3,2.Bacillus licheniformis strain MR10,3.Bacillus altitudinis strain RR11,4.Bacillus pumilus strain RR28,and 5.Bacillus velezensis strain RL3,which displayed compatibility and strong inhibition of the growth of R.solani WH1.These five selected strains,plus one of our previously isolated strain Bacillus subtilis strain 330-2,were targeted for further studies in estimating their potential in plant growth promotion and management of the maize banded leaf and sheath blight(BLSB).All these six strains were comprehensively characterized via in vitro compatibly and antagonism assay against the pathogen(R.solani WH1),and have high potential to produce ammonia,indole-acetic acid(IAA),siderophore,and biological nitrogen fixation,hydrolytic enzyme and solubilized different sources of organic and inorganic zinc and phosphate.After that,the synthetic-communities(Syn Com)were constructed by mixing different bacterial-strains such as Syn Com A(comprising six bacterial-strains designated as 330-2,MR3,MR10,RR11,RR28 and RL3)and Syn Com B(comprising five bacterialstrains designated as MR3,MR10,RR11,RR28 and RL3)and use as the inoculant to suppress pathogen in maize grown under greenhouse experiments.Overall,Sycom A and Sycom B treatments suppressed the higher level of disease and promote growth attributes more significantly as compared to the single bacterial-strain treatments and control(CK).In short,this study establishes an efficient approach to isolate,identify and characterize diverse endophytic microbial-community assembly in maize roots and leaves,to successfully apply selective microbes to improve crop growth in soils affected by soilborne-pathogens.