Cadmium (Cd) is a hazardous heavy metal that threaten fruit safety and soil quality. The remediated effects of wheat straw and fruit pruning branch, with or without Bacillus niescheri, on the physiology and transcriptome of Diospyros lotus L., and soil bio-chemical properties in Cd condition were assessed in this study. Wheat straw and persimmon branch residue addition decreased the Cd availability in soil and Cd accumulation in tissues and alleviated oxidative damage caused by Cd as exhibited by the reduced O2 center dot- , H2O2 and malondialdehyde contents in roots of D. lotus, especially following B. niescheri inoculation. Different expressed genes of ion uptake and translocation were mostly downregulated, whereas cell wall formation/modifications, amino acid metabolism, and phytohormone biosynthesis in roots were upregulated by organic matter plus B. niescheri. Furthermore, organic matter plus B. niescheri improved soil pH, electrical conductivity, cation exchange capacity, enzyme activity (urease, dehydrogenase, catalase), nutrients (nitrogen, phosphorus, potassium) and organic carbon contents. Soil Cd availability was negatively correlated with the relative abundance of Bacteroides, Cellvibrio, Bacillus, Sphingomonas, Vicinamibacteraceae, and Faecalibacterium. Therefore, the organic waste such as wheat straw and branch residues are eco-friendly methods of remediating Cd-contaminated soil and mitigating toxicity for D. lotus, especially following B. niescheri inoculation.

Drought is a major challenge for agriculture worldwide, being one of the main causes of losses in plant production. Various studies reported that some soil's bacteria can improve plant tolerance to environmental stresses by the enhancement of water and nutrient uptake by plants. The Atacama Desert in Chile, the driest place on earth, harbors a largely unexplored microbial richness. This study aimed to evaluate the ability of various Bacillus sp. from the hyper arid Atacama Desert in the improvement in tolerance to drought stress in lettuce (Lactuca sativa L. var. capitata, cv. Super Milanesa) plants. Seven strains of Bacillus spp. were isolated from the rhizosphere of the Chilean endemic plants Metharme lanata and Nolana jaffuelii, and then identified using the 16s rRNA gene. Indole acetic acid (IAA) production, phosphate solubilization, nitrogen fixation, and 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase activity were assessed. Lettuce plants were inoculated with Bacillus spp. strains and subjected to two different irrigation conditions (95% and 45% of field capacity) and their biomass, net photosynthesis, relative water content, photosynthetic pigments, nitrogen and phosphorus uptake, oxidative damage, proline production, and phenolic compounds were evaluated. The results indicated that plants inoculated with B. atrophaeus, B. ginsengihumi, and B. tequilensis demonstrated the highest growth under drought conditions compared to non-inoculated plants. Treatments increased biomass production and were strongly associated with enhanced N-uptake, water status, chlorophyll content, and photosynthetic activity. Our results show that specific Bacillus species from the Atacama Desert enhance drought stress tolerance in lettuce plants by promoting several beneficial plant traits that facilitate water absorption and nutrient uptake, which support the use of this unexplored and unexploited natural resource as potent bioinoculants to improve plant production under increasing drought conditions.