Abstract Plant growth-promoting bacteria (PGPB) are claimed to not only improve plant fitness but also alleviate plant stress. In this study, we evaluated the effect of five PGPB strains on plantlet growth and nutrient and aluminum (Al) uptake under acid soil conditions characterized by low P and K nutrient availability and high metal and aluminum (Al) bioavailability, which may represent a stress condition for crop plants. The PGPB strains were inoculated in sugarcane plantlets produced by meristem tissue culture (MCPs) or one-bud stalks (O-BSPs) and cultivated in soil at 37% Al saturation and pH 4.0. Biomass accumulation and Al and nutrient content in roots and shoots were determined after 30 days of growth. Bacterial inoculation increased root and shoot biomass. However, the magnitudes of these increases were dependent on bacterial strain and plantlet origin. The inoculated plantlets exhibited increased Al content and shifts in Al allocation and calcium (Ca) and boron (B) content among different plant parts (root or shoot), and these changes also depended on plantlet origin and the inoculated strain. The higher Ca uptake of inoculated MCPs and higher B uptake of inoculated O-BSPs may have contributed to reducing the damage caused by excessive Al content. The beneficial microbes also caused changes in plant uptake of micronutrients and slightly reduced macronutrient content. Pseudomonas fluorescens (IAC/BECa 141), Kosakonia radicincitans (IAC/BECa 95), Paraburkholderia tropica (IAC/BECa 135) and Herbaspirillum frisingense (IAC/BECa 152) showed potential for alleviating Al stress in sugarcane plantlets.

中文翻译：

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铝胁迫下甘蔗生长和营养状况的调节取决于有益的内生细菌和植株来源

摘要 植物生长促进菌 (PGPB) 不仅能提高植物的健康状况，还能减轻植物的胁迫。在这项研究中，我们评估了五种 PGPB 菌株在酸性土壤条件下对植株生长以及养分和铝 (Al) 吸收的影响，其特征是磷和钾养分利用率低，金属和铝 (Al) 生物利用率高，这可能代表一种胁迫作物的条件。PGPB 菌株接种在通过分生组织培养 (MCP) 或单芽茎 (O-BSP) 产生的甘蔗幼苗中，并在 37% 铝饱和度和 pH 4.0 的土壤中培养。在生长 30 天后测定根和芽中的生物量积累以及铝和养分含量。细菌接种增加了根和芽的生物量。然而，这些增加的幅度取决于细菌菌株和植株来源。接种的小植株表现出增加的铝含量以及不同植物部分（根或芽）之间的铝分配和钙（Ca）和硼（B）含量的变化，这些变化还取决于小植株来源和接种菌株。接种的 MCP 较高的 Ca 吸收和接种的 O-BSP 较高的 B 吸收可能有助于减少过量 Al 含量造成的损害。有益微生物还导致植物对微量营养素的吸收发生变化，并略微降低宏量营养素含量。Pseudomonas fluorescens (IAC/BECa 141)、Kosakonia radicincitans (IAC/BECa 95)、Paraburkholderia tropica (IAC/BECa 135) 和 Herbaspirillum frisingense (IAC/BECa 152) 显示出减轻甘蔗植株铝胁迫的潜力。