Plant growth-promoting bacteria (PGPB)-assisted phytoremediation, is a promising technique for the removal of copper (Cu) from contaminated soils. Moreover, soil salinity is considered to be one of the major threats to plant growth, and may therefore affect the progress and impact of the plant-driven phytoremediation. In this regard, the multiple interactions among Cu-salinity-plant-microbe, remain largely unknown. This study aimed to investigate the potential of PGPB on phytostabilization of Cu contaminated soils using Helianthus annuus growing under salinity stress. A pot experiment was carried out to determine the effects of Cu and salinity tolerant PGPB inoculation in the phytoremediation of Cu-spiked soils by H. annuus under salt-stressed and non-stressed conditions. Cu- and salinity-tolerant bacterial strains were isolated from Cu contaminated soils. Out of the eight bacterial isolates, SLP6 was selected and identified as Pseudomonas citronellolis by 16S rRNA and characterized in terms of its Cu resistance (up to 400 mg L−1), salinity tolerance (up to 8% NaCl, w/v) and plant growth promoting (PGP) traits. Strain SLP6 displayed 1-aminocyclopropane-1-carboxylic acid deaminase activity, indole-3-acetic acid production, siderophores production, and phosphate solubilization under normal, Cu (100–400 mg L−1) and NaCl (2–8%, w/v) stressed conditions. The inoculation of H. annuus seeds with SLP6 strain significantly enhanced the plant growth, chlorophyll content, anti-oxidant enzymes production and Cu accumulation potential under Cu contamination with and without salt stress, whereas they reduced lipid peroxidation. Pseudomonas citronellolis strain SLP6 could be used as a bio-inoculant for improving the phytostabilization of Cu-contaminated saline soils.

中文翻译：

---

香茅假单胞菌 SLP6 提高盐分胁迫下铜污染土壤中向日葵的植物修复效率

植物生长促进细菌 (PGPB) 辅助的植物修复是一种很有前途的技术，可从受污染的土壤中去除铜 (Cu)。此外，土壤盐分被认为是植物生长的主要威胁之一，因此可能会影响植物驱动的植物修复的进展和影响。在这方面，Cu-盐度-植物-微生物之间的多重相互作用在很大程度上仍然未知。本研究旨在利用盐度胁迫下生长的向日葵研究 PGPB 对铜污染土壤的植物稳定作用。进行了盆栽试验，以确定在盐胁迫和非胁迫条件下，黄花菜对含铜土壤的植物修复中铜和耐盐 PGPB 接种的影响。从铜污染的土壤中分离出耐铜和耐盐的细菌菌株。在 8 个细菌分离株中，SLP6 被 16S rRNA 选择并鉴定为香茅假单胞菌，并以其抗铜（高达 400 mg L-1）、耐盐性（高达 8% NaCl，w/v）和植物生长促进 (PGP) 性状。菌株 SLP6 在正常、Cu (100–400 mg L−1) 和 NaCl (2–8%, w /v) 压力条件。在有和无盐胁迫的情况下，用 SLP6 菌株接种 H. annuus 种子显着提高了植物生长、叶绿素含量、抗氧化酶的产生和铜的积累潜力，但它们减少了脂质过氧化。