A total of ten 1-aminocyclopropane-1-carboxylate (ACC) deaminase producing PGPR isolates were selected and evaluated for the induction of drought stress tolerance in tomato. Among the selected PGPR, maximum seed (laboratory) and plant growth promotion (greenhouse) was observed in tomato seeds bacterized with Bacillus subtilis Rhizo SF 48. The genomic study confirmed the presence of ACC deaminase gene in Rhizo SF 48 and the obtained sequence was deposited to the NCBI database with the Accession No. MK652706. The tomato plants grown upon treatment with Rhizo SF 48 significantly enhanced plant growth even after exposing to different levels of drought stress as compared to stress induced control plants. About 7.5% and 38% increase in RWC were observed in Rhizo SF 48 treated tomato plants grown under well-watered and stress conditions (S4) compared to their control plants, respectively. An increase of 0.76, 0.23 and 0.78 fold in proline, SOD and APX activity and a decrease of 0.3 fold in MDA and H₂O₂ contents were observed in Rhizo SF 48 treated plants compared to control plants grown under S4 conditions. The histo-chemical studies showed lower accumulations of H₂O₂ and superoxide anion in the leaves of Rhizo SF 48 treated plants under drought stress, which was in confirmation with the quantification results of H₂O₂ and SOD. The qRT-PCR studies on drought (Le25) and ethylene responsive factor (SlERF84) marker genes showed that a significant decrease of 0.75 and 0.81 folds, respectively in Le25 and SlERF84 accumulation was observed in Rhizo SF 48 treated plants compared to untreated plants grown under S4 conditions. From the results, it can be attributed that ACC deaminase producing Rhizo SF 48 was able to protect tomato plants against oxidative damage caused due to drought stress and enhanced plant growth promotion. It can be concluded that ACC deaminase producing Rhizo SF 48 can serve as a useful bio-inoculant for sustainable tomato production in arid and semi-arid regions with water deficit.

选择总共十个产生 PGPR 分离株的 1-氨基环丙烷-1-甲酸酯 (ACC) 脱氨酶并评估其对番茄干旱胁迫耐受性的诱导。在选定的 PGPR 中，在用枯草芽孢杆菌Rhizo SF 48 接种的番茄种子中观察到了最大的种子（实验室）和植物生长促进（温室）。基因组研究证实了 Rhizo SF 48 中存在 ACC 脱氨酶基因，并将获得的序列保藏到 NCBI 数据库，登录号为 MK652706。与胁迫诱导的对照植物相比，即使在暴露于不同水平的干旱胁迫后，经 Rhizo SF 48 处理后生长的番茄植物也显着增强了植物生长。与对照植物相比，在浇水良好和胁迫条件（S4）下生长的 Rhizo SF 48 处理的番茄植物中观察到 RWC 分别增加了约 7.5% 和 38%。与在S4条件下生长的对照植物相比，在Rhizo SF 48处理的植物中观察到脯氨酸、SOD和APX活性增加了0.76、0.23和0.78倍，并且MDA和H ₂ O ₂含量降低了0.3倍。组织化学研究表明，在干旱胁迫下，Rhizo SF 48 处理的植物叶片中 H ₂ O ₂和超氧阴离子的积累量较低，这与 H ₂ O ₂和 SOD 的定量结果得到了证实。对干旱（ Le25 ）和乙烯反应因子（ SlERF84 ）标记基因的qRT-PCR研究表明，显着降低了0.75和0.与在S4条件下生长的未处理植物相比，在Rhizo SF 48处理的植物中观察到Le25和SlERF84积累分别是81倍。从结果来看，可以归因于产生 ACC 脱氨酶的 Rhizo SF 48 能够保护番茄植物免受干旱胁迫引起的氧化损伤，并增强植物生长促进作用。可以得出结论，产生 ACC 脱氨酶的 Rhizo SF 48 可作为一种有用的生物接种剂，用于缺水的干旱和半干旱地区的可持续番茄生产。