Plant growth-promoting rhizobacteria (PGPR) boost crop yields and reduce environmental pressures through biofilm formation in natural climates. Recently, biofilm-based root colonization by these microorganisms has emerged as a promising strategy for agricultural enhancement. The current work aims to characterize biofilm-forming rhizobacteria for wheat growth and yield enhancement. For this, native rhizobacteria were isolated from the wheat rhizosphere and ten isolates were characterized for plant growth promoting traits and biofilm production under axenic conditions. Among these ten isolates, five were identified as potential biofilm-producing PGPR based on in vitro assays for plant growth-promoting traits. These were further evaluated under controlled and field conditions for their impact on wheat growth and yield attributes. Surface-enhanced Raman spectroscopy analysis further indicated that the biochemical composition of the biofilm produced by the selected bacterial strains includes proteins, carbohydrates, lipids, amino acids, and nucleic acids (DNA/RNA). Inoculated plants in growth chamber resulted in larger roots, shoots, and increase in fresh biomass than controls. Similarly, significant increases in plant height (13.3, 16.7%), grain yield (29.6, 17.5%), number of tillers (18.7, 34.8%), nitrogen content (58.8, 48.1%), and phosphorus content (63.0, 51.0%) in grains were observed in both pot and field trials, respectively. The two most promising biofilm-producing isolates were identified through 16 s rRNA partial gene sequencing as Brucella sp. (BF10), Lysinibacillus macroides (BF15). Moreover, leaf pigmentation and relative water contents were significantly increased in all treated plants. Taken together, our results revealed that biofilm forming PGPR can boost crop productivity by enhancing growth and physiological responses and thus aid in sustainable agriculture.

Agricultural Biotechnology Research Institute AARI Faisalabad 38000 Pakistan

College of Agronomy Gansu Agricultural University Lanzhou 730070 China Lahore Pakistan

Department of Agrochemistry Soil Science Microbiology and Plant Nutrition Faculty of AgriSciences Mendel University in Brno Zemedelska 1 61300 Brno Czech Republic

Department of Botany and Microbiology College of Science King Saud University Riyadh 11451 Saudi Arabia

Department of Chemistry University of Agriculture Faisalabad 38040 Pakistan

Department of Plant Breeding and Genetics University of Agriculture Faisalabad 38040 Pakistan

Director Programs and Projects Department Islamic Organization for Food Security 019900 Astana Kazakhstan

Institute of Soil and Environmental Sciences University of Agriculture Faisalabad 38040 Pakistan

Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems South China Botanical Garden Chinese Academy of Sciences Guangzhou 510650 China

Soil Bacteriology Section Agricultural Biotechnology Research Institute AARI Faisalabad 38000 Pakistan

Wheat Breeding Group Plant Breeding and Genetics Division Nuclear Institute for Agriculture and Biology Faisalabad 38000 Pakistan

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