Hami Asma, El Attar Imane, Mghazli Najoua, Ennajeh Salah, Ait-Ouakrim El Houcine, Bennis Meryeme, Oulghazi Said, Badaoui Bouabid, Aurag Jamal, Sbabou Laila, Taha Kaoutar
Microbiology and Molecular Biology Team, of Plant and Microbial Biotechnology, Biodiversity and Environment, Faculty of Sciences, Mohammed V University, Rabat, Morocco.
AgroBioscience Program, University Mohammed VI Polytechnic (UM6P), Benguerir, Morocco.
Front Plant Sci. 2025 Feb 26;16:1528923. doi: 10.3389/fpls.2025.1528923. eCollection 2025.
Harnessing plant growth-promoting rhizobia presents a sustainable and cost-effective method to enhance crop performance, particularly under drought stress. This study evaluates the variability of plant growth-promoting (PGP) traits among three strains of LMR575, LMR571, and LMR655, and two native PGP strains LMR698 and LMR696. The primary objective was to assess the host range specificity of these strains and their effectiveness in improving drought tolerance in three legume species: , , and .
experiments were conducted to assess the PGP traits of the selected strains, including phosphate solubilization, indole-3-acetic acid (IAA) production, and siderophore production. Greenhouse trials were also performed using a mixed inoculum of performing strains to evaluate their effects on plant physiological and biochemical traits under drought conditions.
Significant variability in PGP traits was observed among the strains. LMR655 exhibited the highest phosphate solubilization (113.85 mg mL PO ), while LMR571 produced the highest IAA concentration (25.37 mg mL). LMR696 demonstrated 82% siderophore production. Symbiotic interactions varied, with LMR571 and LMR655 forming associations with and , but none establishing compatibility with . Greenhouse experiments showed that a mixed inoculum of LMR571, LMR655, and LMR696 significantly improved proline, total soluble sugars, proteins, and chlorophyll content under drought stress, with showing the strongest response.
These findings highlight the importance of strain selection based on host specificity and PGP potential. The enhanced drought tolerance observed suggests that tailored microbial inoculants can improve legume resilience in water-limited environments. This study provides valuable insights for optimizing bioinoculant formulations to enhance crop performance under drought stress.
利用促进植物生长的根瘤菌是一种可持续且经济高效的方法，可提高作物性能，特别是在干旱胁迫条件下。本研究评估了三株LMR575、LMR571和LMR655以及两株本地促植物生长菌株LMR698和LMR696之间促植物生长（PGP）特性的变异性。主要目的是评估这些菌株的宿主范围特异性及其在提高三种豆科植物（此处原文缺失三种豆科植物具体名称）耐旱性方面的有效性。
进行实验以评估所选菌株的PGP特性，包括磷溶解、吲哚 - 3 - 乙酸（IAA）产生和铁载体产生。还使用性能菌株的混合接种物进行温室试验，以评估它们在干旱条件下对植物生理和生化特性的影响。
在菌株之间观察到PGP特性存在显著变异性。LMR655表现出最高的磷溶解能力（113.85毫克/毫升PO ，此处原文PO后信息缺失），而LMR571产生的IAA浓度最高（25.37毫克/毫升）。LMR696表现出82%的铁载体产生率。共生相互作用各不相同，LMR571和LMR655与（此处原文缺失相关植物名称）形成关联，但与（此处原文缺失相关植物名称）均未建立兼容性。温室实验表明，LMR571、LMR655和LMR696的混合接种物在干旱胁迫下显著提高了脯氨酸、总可溶性糖、蛋白质和叶绿素含量，（此处原文缺失相关植物名称）表现出最强的反应。
这些发现突出了基于宿主特异性和PGP潜力进行菌株选择的重要性。观察到的增强的耐旱性表明，定制的微生物接种剂可以提高豆科植物在水分受限环境中的恢复力。本研究为优化生物接种剂配方以提高干旱胁迫下的作物性能提供了有价值的见解。
