Table 1.

Examples of plant growth-promoting microorganisms. The effect of PGPM on plants and, if known, the mode of action of microorganisms is also included.

PGPM	Plant	Remarks	References
Bacteria
Acinetobacter sp. RG30, Pseudomonas putida GN04	Zea mays	Plant: - increased tolerance to Cu - enhanced chlorophyll content - increased Cu concentration in tissues Bacteria: - IAA synthesis - production of siderophores - solubilization of Cu and P	[17]
Acinetobacter sp. RSC9	Saccharum sp.	Plant: - under salt stress enhanced number of leaves, fresh, dry weight, and germination ratio Bacteria: - IAA production - P, K, and Zn solubilization - N2 assimilation	[18]
Agrobacterium sp. 10C2	Phaseolus vulgaris	- increased nodule formation - higher plant biomass - enhanced content of P, polyphenols, and flavonoids in grains - changes in the structure of the microbial community	[19]
Arthrobacter globiformis	Zea mays, Triticum aestivum	Plant: - enhanced biomass, uptake of Fe and P, and higher chlorophyll content under iron-stress Bacteria: - siderophores production	[20]
Arthrobacter sp., Bacillus megaterium	Lycopersicon esculentum	- enhanced seed germination ratio, seedling length, and dry and fresh weight under salt stress	[21]
Azospirillum brasilense	Cicer arietinum	- increased resistance to Ascochyta rabiei via induction of plant defense-related genes (Snakin2 and DEF0422)	[22]
Azospirillum lipoferum	Triticum aestivum	- improved germination, plant growth, higher chlorophyll content, and improved membrane stability under salt stress - increased production of SOD and osmolytes, i.e., proline, soluble protein, and sugars under salt stress	[23]
Azotobacter spp.	Zea mays	Plant: - increased shoot dry weight, chlorophyll content, and N, P, Fe concentration under drought stress Bacteria: - production of siderophores	[24]
Bacillus amyloliquefaciens	Zea mays	- increased tolerance to salt stress, enhanced content of chlorophyll, soluble sugars, and glutathione, higher peroxidase/catalase activity	[25]
Bradyrhizobium sp., Rhizobium leguminosarum, Azotobacter sp.	Gossypium hirsutum	Plant: - increased rate of seedling emergence, biomass, and N uptake Bacteria: - IAA production	[26]
Burkholderia phytofirmans PsJN	Triticum aestivum	- improved water content and CO2 assimilation rate, water use efficiency, chlorophyll content, and higher yield under drought stress - improved ionic balance, antioxidant levels, higher N, P, K, and protein content in grains	[27]
Burkholderia tropica	Lycopersicum esculentum	Plant: - increased yield Bacteria: - N-fixation and P solubilization	[28]
Enterobacter cloacae	Spinacia oleracea	- protection against Fusarium wilt (Fusarium oxysporum)	[29]
Frankia spp.	Casuarina glauca, Casuarina equisetifolia	- salt stress alleviation, higher dry biomass, chlorophyll, and proline content	[30]
Methylobacterium sp. 2A	Arabidopsis thaliana, Solanum tuberosum	Plant: - the alleviation of salt stress of A. thaliana, with higher lateral roots density, number of leaves, and larger rosette diameter - reduced necrotic lesions and chlorosis in S. tuberosum infected with P. infestans Bacteria: - production of IAA, P solubilization, biocontrol activity against Phytophtora infestans, Botrytis cinerea, and Fuasrium gramiearum	[31]
Pseudomonas putida	Lycopersicum esculentum	Plant: - increased plant height, stem diameter, radical volume, dry biomass, and fruit yield Bacteria: - production of IAA	[32]
Pseudomonas sp. DW1	Solanum melongena	- salt stress ameliorating effect, with increased dry weight, and seed germination - higher SOD activity in leaves	[33]
Pseudomonas stutzeri ISE12	Brassica napus	- enhanced growth under salt stress, with a decrease in non-enzymatic antioxidants accumulation - improved seed germination ratio, number of leaves, chlorophyll content, and dry weight	[34]
Rhizobium leguminosarum, Rhizobium sp., Bradyrhizobium sp.	Oryza sativa	Plant: - increased yield and uptake of N, P, K, and Fe - improved seed vigor, dry biomass, and leaf area with faster seedling emergence Bacteria: - production of IAA	[35,36]
Serratia marcescens	Solanum melongena	- salt stress alleviation, decreased Na+/Cl- content in leaves, lower lipid peroxidation level, and higher activity of antioxidant enzymes - enhanced biomass, longer stems, and bigger leaf area	[37]
Serratia proteamaculans, Pseudomonas putida, Pseudomonas aeruginosa	Triticum aestivum	Plant: - salt stress alleviation with enhanced plant height, root length, and yield, and higher chlorophyll content Bacteria: - ACC deaminase production	[23]
Streptomyces sp.	Arabidopsis thaliana, Lycopersicon esculentum	Plant: - salt stress alleviation with increased biomass, chlorophyll content, and decreased proline content Bacteria: - production of IAA, ACC deaminase, P, and NaCl solubilization	[38]
Streptomyces sp.	Medicago sativa	- protection against root-lesion nematode (Pratylenchus penetrans)	[39]
Fungi
Alternaria solani IA300	Capsicum annum	- enhanced number of leaves, flowers, dry, and fresh weight	[40]
Apergillus niger 9-p	Phasoleus vulgaris	Plant: - increased biomass Fungus: - production of IAA, ACC deaminase, siderophores, protease, amylase, pectinase, xylanase, and P solubilization	[41]
Aspergillus fumigatus	Glycine max	Plant: - salt stress alleviation with enhanced biomass, leaf area, chlorophyll content, and photosynthetic rate - increased isoflavones, proline, SA, and JA content and lower ABA content Fungus: - GAs production (GA4, GA9, GA12)	[42]
Collybia tuberosa, Clitocybe sp., Laccaria laccata, Hebeloma mesophaeum, Cyathus olla	Brassica napus	Plant: - enhanced root and shoot growth, number of leaves, and biomass Fungi: - production of IAA	[43]
Funneliformis mosseae, Ensifer meliloti	Vitis vinifera	- enhanced plant height and dry weight - higher VOCs content in roots	[44]
Fusarium equiseti, Glomus mosseae	Cucumis sativus	- protection against anthracnose (Colletotrichum orbiculare) and damping off (Rhizoctonia solani) - enhanced shoot dry weight	[45]
Fusarium verticillioides, Humicola sp.	Glycine max	- salt stress alleviation with increased shoot length, protein content, carotenoid, salicylic acid (SA), and enhanced SOD activity - decreased ABA level and lipid peroxidation level	[46]
Glomus intraradices, Glomus mosseae	Olea europaea	- enhanced yield, dry weight, height, stem diameter, and root length	[47]
Lecanicillium psalliotae	Elettaria cardamomum	Plant: - enhanced shoot and root length, biomass, and number of leaves - higher chlorophyll content Fungus: - production of IAA, ammonia, siderophores, and cell-wall degrading enzymes - P and Zn solubilization	[48]
Mortierella antarctica, Mortierella. Verticillata	Triticum aestivum	Plant: - enhanced fresh weight Fungi: - production of IAA, GA, and ACC deaminase	[49]
Mucor sp.	Arabidopsis arenosa	- heavy metal (Zn, Cd, Fe, Pb) stress alleviation with enhanced biomass, root hair growth, improved water, and P content - upregulation of genes involved in nutrient acquisition (HRS1, SPX1, MGD2), and metal homeostasis (MTPA2, ZIP7, IREG2, IRT2)	[50]
Penicillium bilaii	Pisum sativum	- increased root dry weight, length, and P content in the shoot	[51]
Penicillium sp., Penicillium radicum, Penicillium bilaiae	Medicago lupulina, Lens culinaris, Triticum aestivum	- enhanced shoot growth and dry weight, and increased P uptake	[52]
Phoma sp.	Cucumis sativus, Arabidopsis thaliana	- protection against cucumber mosaic virus (CMV) via ISR - higher number of leaves, increased fresh/dry weight, and the yield of cucumber	[53]
Phoma spp., Trichoderma asperellum, Fusarium equiseti, Penicillium simplicissmum	Allium cepa	- protection against white rot disease (Sclerotium cepivorum) with enhanced plant height, dry weight, and bulb perimeter - enhanced levels of peroxidase and polyphenol oxidase - upregulation of plant defense genes (PR1, PR2)	[54]
Purpureocillium lilacinum, Purpureocillium. lavendulum, Metarhizium marquandii	Zea mays, Phaseolus vulgaris, Glycine max	Plant: - enhanced plant height and biomass and N content in roots (Z. mays) and P in shoots (P. vulgaris) Fungi: - P solubilization and IAA production	[55]
Trichoderma hamatum, Trichoderma harzianum, Trichoderma viride	Freesia refracta	- accelerated flowering and enhanced development of lateral inflorescence shoots - increased K, Fe, Mn, and Zn uptake	[56]
Trichoderma harzianum	Curcuma longa	Plant: - enhanced plant height and yield Fungi: - biocontrol activity against rhizome rot and leaf blight (Pythium aphanidermatum, Rhizoctonia solani) - production of IAA, HCN, cellulase, and P solubilization	[57]
Trichoderma phayaoense	Cucumis melo	Plant: - enhanced plant development, biomass, and fruit yield Fungus: - biocontrol activity against gummy stem blight pathogens (Stagonosporopsis cucurbitacearum, Fusarium equiseti)	[58]
Trichoderma viride	Brassica napus	- enhanced biomass, lateral roots development, and germination ratio - changes in microbial composition	[59]
Algae
Anabaena oryzae, Anabaena doliolum, Phormidium fragile, Calothrix geitonos, Hapalosiphon intricatus, Aulosira ferilissima, Tolypothrix tenuis, Oscillatoria acuta, Plectonema boryanum	Oryza sativa	- enhanced shoot and root length and biomass - improved protein, phenolics, flavonoids, and chlorophyll content - a higher activity of enzymes (peroxidase, phenylalanine, and ammonia lyase) - elevated levels of IAA, and IBA	[60]
Anabaena variabilis, Anabaena laxa	Lycopersicon esculentum	- protection against Fusarium wilt (F. oxysporum) with significant enhancement of growth, yield, and fruit quality - increased N, P, and Zn concentration - increased activity of defense enzymes (phenylalanine ammonia-lyase, polyphenol oxidase), increased activity of chitosanase, and β-1,3-glucanase	[61]
Calothrix elenkinii	Oryza sativa	- enhanced root/shoot length and fresh weight - improved chlorophyll and IAA content - higher nitrogenase and CMCase activity - 10-fold increase in microbiome population abundance	[62]
Calothrix sp., A. laxa, Anabaena torulosa, Anabaena azollae, Anabaena oscillarioides	Triticum aestivum	- enhanced biomass - nitrogen-fixing potential - higher endoglucanase activity	[63]
Chlorella fusca	Cucumis sativus	- protection against anthracnose (Colletotrichum orbiculare) via the induction of SAR	[64]
Chlorella oocystoides, Chlorella minutissima	Zea mays	- enhanced chlorophyll, P, and K content - improved biomass	[65]
Chlorella vulgaris	Telfairia occidentalis	- enhanced germination ratio - higher number of leaves and yield - improved chlorophyll, carbohydrates, proteins, and lipid content	[66]
Microcystis aeruginsa	Oryza sativa	- heavy metal (Cd) stress alleviation with decreased Cd accumulation, increased translocation of Cd from root to shoot, and enhanced dry weight	[67]
Nostoc sp.	Triticum aestivum, Oryza sativa	Plant: - enhanced biomass and shoot/root length Algae: - production of IAA and zeatin	[68]
Nostoc sp.	Zea mays	- enhanced dry mass - higher N content - production of exopolysaccharide	[69]
Scenedesmus quadricauda, Chlorella vulgaris	Lycopersicon esculentum	- enhanced biomass and root length	[70]
Spirulina platensis	Zea mays	- cadmium stress alleviation with improved photosynthetic electron flows and increased non-photochemical quenching - enhanced seed germination, shoot length, root fresh weight, and bigger leaf area - decreased Cd accumulation in shoot	[71]
Mixed inoculants
Anabaena ssp., Calothrix sp., Providencia sp.	Triticum aestivum	- enhanced yield and Fe, Cu, Zn, Mn, and protein content of grains	[72]
Glomus fasciculatum, Bacillus subtilis	Tagetes erecta	- enhanced flowering, with improved fresh weight and color of flowers	[73]
Klebsiella variicola, Glomus multisubtensum, Rhizophagus intraradices	Helianthus tuberosus	Plant: - enhanced biomass, yield, plant height, and leaf area - increased content of inulin in tubers Microbes: - P solubilization and IAA production	[74]
Mesorhizobium mediterraneum, Rhizophagus irregulari	Cicer arietinum	- enhanced yield and protein content of grain under water deficit conditions	[75]
Rhizophagus intraradices, Glomus aggregatum, Glomus viscosum, Claroideoglomus etunicatum, Claroideoglomus claroideum, Pseudomonas fluorescens, Linum usitatissimum	Solanum lycopersicum	- enhanced flower and fruit production, with increased lycopene, vitamins, sugars, and citric acid content of the fruits	[76]
Rhizophagus intraradices, Pseudomonas sp., Bacillus sp.	Sulla carnosa	Plant: - enhanced biomass, stomatal conductance, photosynthetic pigment content, and photosynthesis rate under salt stress - increased proline content and higher activity of antioxidative enzymes Microbes: - production of IAA	[77]
Septoglomus constrictum, Diversispora aunantia, Archaeospora trappei, Glomus versiforme, Paraglomus ocultum, Bacillus thuringiensis	Lavandula dentata	Plant: - increased biomass under drought stress conditions, enhanced activity of the enzymatic antioxidant system, and enhanced nutrient uptake Microbes: - P solubilization, production of IAA, and ACC deaminase	[78]
Trichoderma harzianum, Glomus spp., Pseudomonas fluorescens	Capsicum annuum	- enhanced yield, higher activity of antioxidative, and defense enzymes	[79]