TABLE 1.
Salt-tolerant plant growth promoting rhizobacteria and their possible roles in enhancing yield and growth of diverse plants/crops.
| Crops | ST-PGPR | Mechanism | References |
| Sunflower | P. fluorescens | IAA production, siderophore production and K+/Na+ ratio | Shilev et al., 2012 |
| Pseudomonas aeruginosa | EPS production | Tewari and Arora, 2014b | |
| Pseudomonas sp. | IAA production, phosphate solubilization, siderophore, nitrogen fixation, HCN, chitinase and β-1-3 glucanase activity | Tewari and Arora, 2016 | |
| Soybean | P. putida H-2-3 | ABA, salicylic acid and JA and gibberellins | Kang et al., 2014 |
| Bradyrhizobium japonicum USDA 110 and P. putida TSAU1 | Root system physiology, nitrogen and phosphorus acquisition and nodule formation | Egamberdieva et al., 2017a | |
| Bacillus firmus SW5 | Antioxidant enzyme and alternation in root system architecture | El-Esawi et al., 2018a | |
| Bradyrhizobium japonicum, Bacillus subtilis SU-12 and Serratia proteamaculans | Antioxidant enzyme and Proline content | Han and Lee, 2005 | |
| Pseudomonas simiae | IAA production, phosphate solubilization and siderophore production | Vaishnav et al., 2016 | |
| B. japonicum and B. subtilis | EPS production, antioxidant activity and concentration of proline | Han and Lee, 2005 | |
| P. fluorescens | CK production | Bhattacharyya and Jha, 2012 | |
| Groundnut | P. aeruginosa AMAAS57 and P. aeruginosa BM6 | IAA production, HCN, ammonia, phosphate solubilization, production of phenol and free amino acids | Ghorai et al., 2015 |
| B. saurashtrense, B. casei, Haererohalobacter | Osmotic stress and proline | Shukla et al., 2012 | |
| P. fluorescens | ACC deaminase | Saravanakumar and Samiyappan, 2007 | |
| Klebsiella, Pseudomonas, Agrobacterium, and Ochrobactrum | IAA production, phosphate solubilization, ACC deaminase | Sharma et al., 2016 | |
| Rape seed | Rhizobium sp. | ACC deaminase, IAA production and phosphate solubilization | Saghafi et al., 2018 |
| P. fluorescens and P. putida | ACC deaminase, IAA and hydrogen cyanide | Jalili et al., 2009 | |
| P. putida UW4 | Photosynthesis, antioxidant enzyme, membrane transportation and pathogenesis-related responses | Cheng et al., 2012 | |
| Cotton seed | P. putida R4 and Pseudomonas chlororaphis R5 | IA production | Egamberdieva et al., 2015 |
| P. putida | Germination rate and biomass | Yao et al., 2010 | |
| Bacillus amyloliquefaciens, Curtobacterium oceanosedimentum and Pseudomonas oryzihabitans | Seed germination | Irizarry and White, 2017 | |
| Klebsiella oxytoca Rs-5, Bacillus sp. SL-13, Bacillus sp. SL-14 and Bacillus sp. SL-44 | Antioxidant enzymes and photosynthetic pigment content | Wu et al., 2012 | |
| Rice | Alcaligens sp., Bacillus sp. and Ochrobactrum sp. | ACC deaminase | Bal et al., 2013 |
| Serratia sp. and Pseudomonas sp. | IAA production, nitrogen fixation, and phosphate solubilization | Nakbanpote et al., 2014 | |
| P. pseudoalcaligenes and B. pumilus | Reduced the toxicity of ROS by reducing plant cell membrane index, cell caspase-like protease activity, and programmed cell death | Jha and Subramanian, 2013 | |
| Bacillus aryabhattai MS3 | Nitrogen fixation, IAA production, phosphorus solubilization and siderophore production | Sultana et al., 2018 | |
| Enterobacter sp. P23 | Phosphate solubilization, IAA production, siderophore production, HCN production | Sarkar et al., 2018 | |
| Halobacillus dabanensis strain SB-26, Halobacillus sp. GSP 34 | Nitrogen fixation and IAA production | Rima et al., 2018 | |
| Pseudomonas strains PF1 and TDK1 | Antioxidant enzyme | Sen and Chandrasekhar, 2015 | |
| B. stratosphericus (NBRI 5Q and NBRI 7A) | Phosphate solubilization, ACC deaminase activity IAA production | Misra et al., 2017 | |
| B. amyloliquefaciens NBRISN13 (SN13) | Betaine, sucrose and trehalose | Nautiyal et al., 2013 | |
| Bacillus and Citrobacter | Nitrogen fixation, phosphate solubilization and IAA production | Habib et al., 2016b | |
| B. pumilus | Antioxidative enzymes | Khan et al., 2016 | |
| Chick pea | P. pseudoalcaligens | Phosphate solubilization, siderophore and IAA production | Patel et al., 2012 |
| Mezorhizobium ciceri | Nodulation and Nitrogen fixation | Egamberdieva et al., 2014 | |
| H. variabilis (HT1) and P. rifietoensis (RT4) | Biofilm formation and EPS | Qurashi and Sabri, 2012a | |
| Mesorhizobium strains | ACC deaminase activity improved nodulation and reduced level of ethylene | Chaudhary and Sindhu, 2015 | |
| Mung bean | Rhizobium and pseudomonas | Photosynthetic rate, chlorophyll content and water use efficiency | Ahmad et al., 2013 |
| Rhizobium sp. | ACC deaminase | Aamir et al., 2013 | |
| P. fluorescens (Mk20) and Rhizobium phaseoli | ACC deaminase | Ahmad et al., 2011 | |
| Lentil | Rhizobium leguminosarum bv.viciae | IAA production and phosphate solubilization | Jida and Assefa, 2011 |
| Pseudomonas jessenii and R. leguminosarum (P10Z22) | ACC deaminase | Zahir et al., 2011 | |
| Rhizobium sp. BCKV MU5 and BCKV MU2 | Nodulation efficiency | Halder et al., 2016 | |
| Pea | Arthrobacter protophormiae with R. leguminosarum and Glomus mosseae | Reduction of ethylene stress through ACC deaminase | Barnawal et al., 2014 |
| Pigeon pea | Bradyrhizobium (RA-5) and Burkholderia cepacia (RRE-5) | Enhancement of root nodulation and N2 fixation | Bano et al., 2015 |
| P. putida, P. fluorescens, Bacillus cereus with Rhizobium strain | Nodulation and N2 fixation | Tilak et al., 2006 | |
| Black gram | P. fluorescens SA8 with kinetin (10 μM) | Improvement in water relation, gas exchange, and photosynthetic content | Yasin et al., 2018 |
| Faba bean | P. putida, P. fluorescens and B. subtilis | Increase in growth traits of plant | Metwali et al., 2015 |
| Pseudomonas anguilliseptica SAW 24 | Biofilm production and EPS production | Mohammed, 2018 | |
| Maize | Pseudomonas syringae, Enterobacter aerogenes and P. fluorescens | ACC deaminase | Nadeem et al., 2007 |
| Azospirillum brasilense | Ion toxicity, NOR and nitrogenase activity | Hamdia et al., 2004 | |
| Pseudomonas and Enterobacter spp. | ACC deaminase | Nadeem et al., 2009 | |
| Azotobacter chroococcum | Improved K+/Na+ratio, polyphenol content and proline concentration | Rojas-Tapias et al., 2012 | |
| Proteus penneri, P. aeruginosa, and A. faecalis | EPS | Naseem and Bano, 2014 | |
| B. amyloliquefaciens | Soluble sugar content and antioxidant enzymes | Chen et al., 2016 | |
| Pantoea agglomerans | Up-regulation of aquaporin genes | Gond et al., 2015 | |
| Rhizobium and Pseudomonas | Osmotic regulation | Bano and Fatima, 2009 | |
| Staphylococcus sciuri | Antioxidant enzymes | Akram et al., 2016 | |
| Bacillus spp. and Arthrobacter pascens | phosphate solubilization, osmotic regulation and antioxidant enzymes | Ullah and Bano, 2015 | |
| Bacillus aquimaris DY-3 | Chlorophyll content, osmotic regulation and antioxidant enzymes | Li and Jiang, 2017 | |
| P. syringae and P. fluorescens | ACC deaminase | Zafar-ul-Hye et al., 2014 | |
| A. brasilense strains Ab-V5 and Ab-V6 and Rhizobium tropici strain CIAT 899 | Antioxidant enzymes and proline contents | Fukami et al., 2018 | |
| Gracilibacillus, Staphylococcus, Virgibacillus, Salinicoccus, Bacillus, Zhihengliuella, Brevibacterium, Oceanobacillus, Exiguobacterium, Pseudomonas, Arthrobacter, and Halomonas spp. | IAA production, ACC deaminase, phosphate solubilization and biofilm formation | Aslam and Ali, 2018 | |
| Serratia liquefaciens KM4 | Facilitated gas exchange, osmoregulation, antioxidant enzymes, nutrient uptake and downregulation of ABA biosynthesis | El-Esawi et al., 2018b | |