This work aimed to assess the ability of plant growth-promoting Bacilli isolated from wheat rhizosphere and rock phosphate mine soils to convert inorganic phosphate (Pi) from Moroccan natural phosphate (NP) to soluble forms. The effect of these bacteria on wheat plants in order to increase their phosphorus (P) uptake in vitro was also investigated. Bacteria were isolated from wheat rhizosphere and natural rock phosphate soils and screened for their ability to solubilize Tri-Calcium Phosphate (TCP) and Natural Rock Phosphate (NP), to produce indole-3-acetic acid (IAA), siderophores and 1-aminocyclopropane-1-carboxylate (ACC) deaminase. Isolates were identified by 16S rRNA sequencing and tested for their capacity to increase wheat plants growth and their phosphorus uptake.Twenty-four strains belonging to Bacillus genus isolated from both biotopes were screened for their ability to solubilize Pi. The highest NP solubilization was showed by strains isolated from wheat rhizosphere. Solubilization of Pi was accompanied by organic acid production. Strains produce IAA, siderophore and ACC deaminase. Inoculation assays using efficient NP-solubilizing bacilli strains from both sources showed the ability of these isolates to increase wheat growth and the phosphorus uptake under in vitro conditions. Bacilli strains isolated from rhizosphere soil and natural rock phosphorus soil showed effective solubilization of Pi from rock phosphate. Phosphate solubilizing Bacilli were evaluated for their plant growth promotion under in vitro conditions. Results revealed the positive effect of all strains on biometric parameters and P content of wheat seedlings.

中文翻译：

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从摩洛哥磷酸盐岩矿和根际土壤中分离的无机磷酸盐增溶菌在小麦（Triticum aestivum L）磷吸收中的作用

这项工作旨在评估从小麦根际和磷矿岩土壤中分离的植物促生长杆菌将无机磷酸盐 (Pi) 从摩洛哥天然磷酸盐 (NP) 转化为可溶形式的能力。还研究了这些细菌对小麦植物的影响，以增加其体外磷 (P) 吸收。从小麦根际和天然磷酸盐岩土壤中分离出细菌，并筛选它们溶解磷酸三钙 (TCP) 和天然岩磷酸盐 (NP) 的能力，以产生吲哚-3-乙酸 (IAA)、铁载体和 1-氨基环丙烷-1-羧酸（ACC）脱氨酶。通过 16S rRNA 测序鉴定分离株，并测试其促进小麦植株生长和磷吸收的能力。对从两种生境中分离的属于芽孢杆菌属的 24 株菌株进行了筛选，以确定它们溶解 Pi 的能力。从小麦根际分离的菌株表现出最高的 NP 溶解度。Pi的溶解伴随着有机酸的产生。菌株产生 IAA、铁载体和 ACC 脱氨酶。使用来自两种来源的高效 NP 溶解杆菌菌株进行的接种试验表明，这些分离株在体外条件下能够增加小麦生长和磷吸收。从根际土壤和天然岩磷土壤中分离出的杆菌菌株显示出对磷岩中磷的有效溶解。在体外条件下评估了增溶磷酸盐的杆菌的植物生长促进作用。