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Humanity in the modern world is confronted with diverse problems at several levels. The environmental concern is probably the most important as it threatens different ecosystems, food, and farming as well as humans, animals, and plants. More specifically, salinization of agricultural soils is a global concern because of on one side, the permanent increase of the areas affected, and on the other side, the disastrous damage caused to various plants affecting hugely crop productivity and yields. Currently, great attention is directed towards the use of Plant Growth Promoting Bacteria (PGPB). This alternative method, which is healthy, safe, and ecological, seems to be very promising in terms of simultaneous salinity alleviation and improving crop productivity. This review attempts to deal with different aspects of the current advances concerning the use of PGPBs for saline stress alleviation. The objective is to explain, discuss, and present the current progress in this area of research. We firstly discuss the implication of PGPB on soil desalinization. We present the impacts of salinity on crops. We look for the different salinity origin and its impacts on plants. We discuss the impacts of salinity on soil. Then, we review various recent progress of hemophilic PGPB for sustainable agriculture. We categorize the mechanisms of PGPB toward salinity tolerance. We discuss the use of PGPB inoculants under salinity that can reduce chemical fertilization. Finally, we present some possible directions for future investigation. It seems that PGPBs use for saline stress alleviation gain more importance, investigations, and applications. Regarding the complexity of the mechanisms implicated in this domain, various aspects remain to be elucidated.

A new bacterial isolate (NH) from salt‐affected soil was identified as Azospirillum brasilense using phenotypic analyses and 16S rDNA‐based phylogeny. This isolate showed resistance towards 3,4‐dehydroproline and optimal growth at 200 mmol/L NaCl, tolerating salt stress of 300 mmol/L NaCl in the absence of osmoprotectants and up to 600 mmol/L NaCl in the presence of glycine betaine and Ulva lactuca extracts. This effect was enhanced with extracts of the marine algae Ulva lactuca. A. brasilense strain NH can produce auxin indole acetic acid under saline conditions. The hypothesis was tested that the inoculation of this osmotolerant rhizosphere strain could improve the growth of wheat under saline stress conditions. Normal wheat growth was restored in the presence of both 150 mmol/L and 200 mmol/L NaCl after inoculation with A. brasilense NH. Under saline conditions, its effect of promoting plant growth of wheat was significantly superior to that of A. brasilense Sp7, the non‐halotolerant type strain. A. brasilense NH restored wheat growth at elevated salt concentrations in pot and field experiments even better in the presence of osmoprotective Ulva lactuca extracts.

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Abstract. Mokrani S, Bejaoui B, Belabid L, Nabti E, Mokrani S. 2020. Potential of Pseudomonas stutzeri strains isolated from rhizospheric soil endowed with antifungal activities against phytopathogenic fungus Stemphylium botryosum. Biodiversitas 21: 47-54. In this present study, two Pseudomonas strains P4 and P5 isolated from rhizospheric soil were characterized for PGP (Plant Growth Promoting) traits production like HCN (Hydrogen Cyanid), siderophores and IAA (Indole Acetic Acid). Phylogenic tree based on 16S DNAr identification-related the two strains P4 and P5 to Pseudomonas stutzeri NR 116489 and NR 113652.1. One phytopathogenic fungus St-bt (Stemphylium botryosum) was isolated from Phaseolus vulgaris L. Macroscopic and microscopic identification attributed it to the genus Stemphylium. Antifungal activities of the two Pseudomonas strains P4 and P5 against fungus isolate St-bt had revealed very highly significant inhibition percentages of 38.46± 3.85% and 56.56± 2.22% for each strain, respectively.

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