This study aims to assess the effect of five endophytic bacteria on the growth promotion of tomato plants under salt stress conditions. Twenty-five endophytic bacteria were isolated from roots of the native halophyte Stipa tenacissima L. collected from Djelfa (Algeria) and were evaluated for their halotolerant potential. Seven strong halotolerant isolates were selected and characterized for in vitro Plant Growth Promotion (PGP) including the ACC-deaminase activity, inorganic phosphate solubilization and the production of indole-3-acetic acid and siderophores. Five strains showing high PGP traits were investigated for the mitigation of salt stress and PGP of tomato (Solanum esculentum L. cv. Aïcha). Screening of the salt-tolerant isolates for PGP traits in saline condition (75 mM NaCl) under Petri-dishes experiment of tomato revealed that three isolates ST09, ST18 and ST19 improved the growth of tomato seedlings by highlighting germination rate, shoot and root lengths and biomass. Under greenhouse conditions at 0 and 75 mM NaCl, inoculation of strains ST09, ST18 and ST19 in tomato seedlings produced an increase in germination (69.23%, 73.07% and 73.07%). The isolate ST19 showed an increase of more than 90% in root elongation and 17.4% increase in biomass when compared to uninoculated tomato seedlings at 75 mM NaCl stress. Phylogenetic analysis based on the 16S rRNA gene showed that the strain ST19 belongs to the genus Kocuria, and is closely related to Kocuria arsenatis |CM1E1|KM874399^T (99.29% similarity). Thus, we conclude that the inoculation of tomato plants with the strain ST19 showed its efficiency to mitigate salt stress conditions.

这项研究旨在评估五种内生细菌对盐胁迫条件下番茄植株生长的促进作用。从收集自Djelfa（阿尔及利亚）的天然盐生植物针茅Stipa tenacissima L.的根中分离出25种内生细菌，并对其潜在的耐盐性进行了评估。选择了七种强卤代戊酸酯分离物并进行了体外植物生长促进（PGP）表征，包括ACC脱氨酶活性，无机磷酸盐增溶以及吲哚-3-乙酸和铁载体的生产。研究了5个具有高PGP特性的菌株对番茄（Solanum esculentum L. cv 。Aïcha）。番茄Petri-dishes试验筛选了耐盐盐分离株的盐分条件下的PGP性状（75 mM NaCl），结果表明，三种分离株ST09，ST18和ST19通过突出发芽率，芽和根长以及生物质。在0和75 mM NaCl的温室条件下，接种番茄幼苗中的菌株ST09，ST18和ST19导致发芽增加（69.23％，73.07％和73.07％）。与未接种番茄幼苗在75 mM NaCl胁迫下相比，分离株ST19的根伸长增加了90％以上，生物量增加了17.4％。基于16S rRNA基因的系统发育分析表明，ST19菌株属于Kocuria属，与Arrsenatis紧密相关。| CM1E1 | KM874399 ^T（相似性为99.29％）。因此，我们得出结论，用ST19菌株接种番茄植株显示出缓解盐胁迫条件的效率。