title: Proteomics provides insights into biological pathways altered by plant growth promoting bacteria and arbuscular mycorrhiza in sorghum grown in marginal soil.
abstract: Sorghum is an economically important crop, a model system for gene discovery and a biofuel source. Sorghum seedlings were subjected to three microbial treatments, plant growth promoting bacteria (B), arbuscular mycorrhizal (AM) fungi mix with two Glomus species (G. aggregatum and G. etunicatum), Funelliformis mosseae and Rhizophagus irregularis (My), and B and My combined (My+B). Proteomic analysis was conducted followed by integration with metabolite, plant biomass and nutrient data. Out of 366 differentially expressed proteins in sorghum roots, 44 upregulated proteins overlapping among three treatment groups showed positive correlation with sorghum biomass or element uptake or both. Proteins upregulated only in B group include asparagine synthetase which showed negative correlation with biomass and uptake of elements. Phosphoribosyl amino imidazole succinocarboxamide protein with more than 50-fold change in My and My+B groups correlated positively with Ca, Cu, S and sucrose levels in roots. The B group showed the highest number of upregulated proteins among the three groups with negative correlation with sorghum biomass and element uptake. KEGG pathway analysis identified carbon fixation as the unique pathway associated with common upregulated proteins while biosynthesis of amino acids and fatty acid degradation were associated with common downregulated proteins. Protein-protein interaction analysis using STRING identified a major network with thirteen downregulated proteins. These findings suggest that plant-growth-promoting-bacteria alone or in combination with mycorrhiza enhanced radical scavenging system and increased levels of specific proteins thereby shifting the metabolism towards synthesis of carbohydrates resulting in sorghum biomass increase and uptake of nutrients.
authors.affiliation: Department of Biological Sciences, Michigan Technological University, Houghton, MI, USA; Biotechnology Department, King Faisal University, Saudi Arabia.
authors.forename: Faten
authors.initials: F
authors.lastname: Dhawi
authors.affiliation: Department of Biological Sciences, Michigan Technological University, Houghton, MI, USA. Electronic address: rupdatta@mtu.edu.
authors.forename: Rupali
authors.initials: R
authors.lastname: Datta
authors.affiliation: Department of Biological Sciences, Michigan Technological University, Houghton, MI, USA; Centre for Biochemistry and Microbial Sciences, Central University of Punjab, Bathinda, India. Electronic address: wusirika@gmail.com.
authors.forename: Wusirika
authors.initials: W
authors.lastname: Ramakrishna
mesh_terms: D001419:Bacteria / Q000378:metabolism*; D018533:Biomass; D055137:Glomeromycota / Q000378:metabolism; D038821:Mycorrhizae / Q000378:metabolism*; D063245:Plant Development / Q000502:physiology*; D018517:Plant Roots / Q000378:metabolism / Q000382:microbiology; D018520:Plant Shoots / Q000254:growth & development / Q000378:metabolism / Q000382:microbiology; D040901:Proteomics / Q000379:methods; D036226:Seedlings / Q000254:growth & development / Q000378:metabolism / Q000382:microbiology; D012987:Soil; D045868:Sorghum / Q000254:growth & development / Q000378:metabolism* / Q000382:microbiology*; D013559:Symbiosis / Q000502:physiology
chemical_list: D012987:Soil
keywords: Metabolites; Mycorrhiza; Pathways; Plant growth promoting bacteria; Proteomics