Table 2.

EPS-producing microbial strains in drought tolerance.

Microorganisms	Crops	Functions	References
Rhizobium sp. strain YAS34	Sunflower	Increase RAS/RT ratio, dry biomass, and nitrogen uptake	[24]
Pseudomonas mendocina	Lactuca sativa L	Increase in aggregate stability, water soluble, and total carbohydrates	[50]
Proteus penneri Pseudomonas aeruginosa Alcaligenes faccalis	Maize	Improve soil moisture content, leaf area, root length, shoot length, and plant biomass	[56]
Bacillus sp. (B. amyloliquefaciens, B. licheniformis, B. thuringiensis, B. subtilis, Paenibacillus favisporus)	Maize	Increase plant biomass, relative water content, water potential of leaf, RAS/RT ratio, and aggregate stability	[11]
Rhizobium leguminosarum Mesorhizobium ciceri Rizobium phaseoli	Wheat	Improve growth, biomass, and drought tolerance index	[58]
Rhizobium strain KYGT207	Wheat	Improve soil aggregation	[48]
Bacillus sp. (B. licheniformis, B. megaterium, B. pumilus)	Soybean	Plant growth promotion	[70]
Klebsiella sp. IG3	Wheat	Improve soil aggregation, root adhering soil, and water potential around the roots	[75]
P. aeruginosa PM389 P. aeruginosa ZNP1 B.endophyticus J13 B. tequilensis J12		Increase phytohormones/EPS Enhance fresh weight, dry weight, and plant water content	[68]
Pseudomonas chlororaphis O6	Arabidopsi s thaliana	Reduce stomatal opening and wilting	[72]
B. amyloliquefaciens 54	Tomato	Increase survival rate, relative water content, and root vigor Decrease concentration of malondialdehyde Increase antioxidant enzyme activities Increase levels of stress-responsive genes (lea, tdi65, and ltpg2)	[96]
B. amyloliquefaciens FZB42	A. thaliana	Increase survival rate, fresh and dry shoot weights, and primary root length Increase expression levels of drought defense-related marker genes, such as RD29A, RD17, ERD1, and LEA14 Increase proline production and activities of superoxide dismutase and peroxidase	[66]
Pseudomonas fluorescens DR7 P. fluorescens DR11 Pseudomonas migulae DR35 Enterobacter hormaechei DR16	Foxtail millet	Increase the RAS/RT Improve seed germination	[71]
P. fluorescens FAP2 B. licheniformis B642	Wheat	Enhance vegetative growth Enhance photosynthesis, chlorophyll content, transpiration rate (E), internal CO2 concentration (Ci), stomatal conductance (gs), net photosynthetic rate (PN), and leaf water potential (LWP) as compared to uninoculated control	[62]