Table 1.
Potential application of PGPRs, with multiple plant growth promoting (PGP) traits, associated to halophytes to promote growth and enhance salinity tolerance of non-halophyte and halophyte plants.
| Halotolerant bacteria | Host halophyte | PGP activity | Inoculated plant | Plant response | References |
|---|---|---|---|---|---|
| Bacillus alcalophilus, B. thuringiensis, and Gracilibacillus saliphilus | Arthrocnemum macrostachyum | IAA production, siderophore production, and phosphate solubilization | A. macrostachyum | Mitigated the effects of high salinity on plant growth and physiological performance. | Navarro-Torre et al., 2017 |
| Micrococcus yunnanensis, Planococcus rifietoensis, and Variovorax paradoxus | Seven species of halophytes | N2 fixation, IAA production, siderophore production, phosphate solubilization, and ACC deaminase activity | Sugar beet (Beta vulgaris L.) | An increase in salt stress tolerance, seed germination (%), and plant biomass, and photosynthetic capacity, and a decrease in stress-induced ethylene production at different NaCl concentrations (50–125 mM). | Zhou et al., 2017 |
| Dietzia natronolimnaea STR1 | Not reported | – | Wheat (Triticum aestivum L.) | Increased wheat tolerance to salt stress by improved wheat growth in terms of plant dry weight and plant height (higher biomass, shoot, and root elongation), increased photosynthetic pigments, enhanced content of enzymes catalase and ascorbate peroxidase, and increased the gene expression of the antioxidants compared to un-inoculated plants. | Bharti et al., 2016 |
| Bacillus, Pantoea, Marinobacterium, Acinetobacter, Enterobacter, Pseudomonas, Rhizobium, and Sinorhizobium | Psoralea corylifolia L. | IAA production and siderophore production | Wheat (Triticum aestivum L.) | Enhanced seed germination and root length of wheat | Sorty et al., 2016 |
| Klebsiella, Pseudomonas, Agrobacterium, and Ochrobactrum | Arthrocnemum indicum | IAA production, N2 fixation, phosphate solubilization, ACC deaminase activity, and HCN production | Peanut | A significant increase in total N content (up to 76%), maintained ion homeostasis, accumulated less ROS, and enhanced plant growth compared to non-inoculated seedlings. | Sharma et al., 2016 |
| Serratia marcescens and B. cereus | Aster tripolium L. | IAA production, N2 fixation, siderophore production, and ACC deaminase activity | – | – | Szymańska, et al., 2016 |
| Pseudomonas sp. | Suaeda salsa | – | Cucumber and rice | Increase in plant growth and salt tolerance of plant. | Yuan et al., 2016 |
| Bacillus endophyticus, B. tequilensis, Planococcus rifietoensis, Variovorax paradoxus, and Arthrobacter agilis | Salicornia europaea | IAA production, phosphate solubilization, and ACC deaminase activity | S. europaea | Increase in germination percentage by 7–11%, in shoot length by 13–22%, in plant root length by 44–57%, and in fresh weight by 21–54%. | Zhao et al., 2016 |
| Arthrobacter pascens | Atriplex leucoclada | Phosphate solubilization and siderophore production | Maize | Increase in shoot and root length, in shoot and root fresh and dry weight, in osmolytes (e.g., sugar and proline), and in antioxidant enzymes activity (e.g., superoxide dismutase, peroxidase, catalase and ascorbate peroxidase) of maize plant. | Ullah and Bano, 2015 |
| Suaeda fruticosa | |||||
| Bacillus, Pseudomonas, Klebsiella, Serratia, Arthrobacter, Streptomyces, Isoptericola, and Microbacterium | Limonium sinense | N2 fixation, IAA production, phosphate solubilization, and ACC deaminase activity | L. sinense | Significant increase in plant root length, shoot length, leaf number, and leaf area as compared to the non-inoculated control. | Qin et al., 2014 |
| Chromohalobacter, Marinococcus, Halobacillus, Nesterenkonia, Halomonas, Oceanobacillus, and Virgibacillus | Salicornia strobilacea | IAA, N2 fixation, phosphate solubilization, and ACC deaminase activity | – | – | Mapelli et al., 2013 |
| Rhodococcus fascians | Salicornia sp. | N2 fixation | – | – | Jafari et al., 2012 |
| Brachybacterium saurashtrense sp., Zhihengliuella sp., Brevibacterium casei, Haererehalobacter sp., Halomonas sp., Vibrio sp., Cronobacter sakazakii, Pseudomonas spp., Rhizobium radiobacter, Mesorhizobium sp., and Bacillus sp. | Salicornia brachiata | N2 fixation, IAA production, phosphate solubilization, and ACC deaminase activity | S. brachiata | Increase in percent germination at 0–0.5 mol l−1 NaCl concentrations and significant increases in root length, shoot length, vigor index and the fresh weight of S. brachiate. | Jha et al., 2012 |
| Agrobacterium tumefaciens, Zhinguelliuella, Brachybacterium saurashtrense, Brevibacterium casei, Haererohalobacter, and Vibrio | Salicornia brachiata | IAA production, N2 fixation, phosphate solubilization, siderophore production, and ACC deaminase activity | Arachis hypogaea | Increase in plant length, shoot length, root length, shoot dry weight, root dry weight, and total biomass compared to un-inoculated plants, increase in the percentage of water content in the shoots and roots in inoculated plants compared to un-inoculated plants, and increase in amino acids, K+/Na+ ratio, and content of Ca2+, P, N, and IAA of the inoculated plants. | Shukla et al., 2012 |
| Brachybacterium saurashtrense sp. | Salicornia brachiata | N2 fixation, IAA production, siderophore production, and ACC deaminase activity | – | – | Gontia et al., 2011 |
| Rhizobium spp. and Bacillus spp. | Salicornia bigelovii | N2 fixation | – | – | Rueda-Puente et al., 2010 |
| Brevibacterium epidermidis, B. iodinum, Arthrobacter nicotianae, Zhihengliuella alba, Micrococcus yunnanensis, Oceanimonas smirnovii, Bacillus licheniformis, B. stratosphericus, B. aryabhattai, and Corynebacterium variabile | Not reported | N2 fixation, IAA production, and ACC deaminase activity | Canola | Increase in root length between 5.2 and 47.8%, and in root dry weight between 16.2 and 43%, in comparison with the un-inoculated canola plant. | Siddikee et al., 2010 |
| Pseudomonas oryzihabitans, Pseudomonas sp., Pantoea agglomerans and Pseudomonas putida | Suaeda salsa | IAA production, gibberellic acid production, abscisic acid production, phosphate solubilization, ACC deaminase activity, siderophore production, and antifungal activity | – | – | Teng et al., 2010 |
| Lysinibacillus fusiformis, B. subtilis, Brevibacterium halotolerans, B. licheniformis, B. pumilus, Achromobacter xylosoxidans, and P. putida | Prosopis strombulifera | N2 fixation, IAA production, siderophore production, ACC deaminase activity, gibberellin production, antifungal activity, and protease activity | – | – | Sgroy et al., 2009 |
| Pseudomonas pseudoalcaligenes | Salicornia europea | N2 fixation | S. europea | Increase in the chlorophyll content and N content of S. europea. | Ozawa et al., 2007 |
| Halomonas maura | Salicornia sp. | N2 fixation | – | – | Argandona et al., 2005 |
| Klebsiella pneumoniae | Salicornia bigelovii | N2 fixation | S. bigelovii | Increase in germination, early seedling growth, fresh and dry weights and the length of roots of S. bigelovii. | Rueda-Puente et al., 2003 |
| Azospirillum halopraeferens sp. Nov. | Kallar grass | N2 fixation | – | – | Reinhold et al., 1987 |