Buqori Dwi Mai Abdul Imam, Sugiharto Bambang, Siswoyo Tri Agus, Hariyono Kacung
Department of Agronomy, Faculty of Agriculture, Jember University, Kampus Tegal Boto Jl. Kalimantan 37, Jember, East Java, 68121, Indonesia.
Center for Development of Advanced Sciences and Technology, Jember University, Kampus Tegal Boto Jl. Kalimantan 37, Jember, East Java, 68121, Indonesia.
Sci Rep. 2025 Feb 12;15(1):5259. doi: 10.1038/s41598-025-89457-4.
Plant growth-promoting rhizobacteria (PGPR) are promising candidates that enhance plant growth under stressful conditions. In this study, 10 bacterial isolates were screened for their IAA production, among them JTB1 and MT22 isolates were selected which produced high IAA levels under 10% PEG and 2% NaCl stress. The isolates showed a high capacity for phosphate solubilization and ACC deaminase activity. Phytogenic analysis showed that the isolate belonged to Bacillus megaterium species JTB1 and MT22. Application of JTB1, MT22, and their consortia as PGPR significantly promoted root development and sugarcane growth under moderate and severe drought stress. Sugarcane growth promotion resulted from the retardation of reactive oxygen species (ROS) synthesis, malondialdehyde (MDA), electrolyte leakage, and cell damage by increasing antioxidant scavenging systems, such as catalase (CAT) and ascorbate peroxidase (APX), owing to PGPR inoculation under drought stress. Inoculation with PGPR resulted in increased auxin transporter expression, which modulated the increase in photosynthetic gene expression of RBC-L, PEPC, SPS in sugarcane under drought stress. The application of JTB1, MT22, or their consortia seemed to have similar effects on all observed parameters. Collectively, these results indicated that inoculation with PGPR enhanced root development and increased the antioxidant system and photosynthetic activity, which promoted sugarcane growth under drought stress.
植物促生根际细菌（PGPR）是在胁迫条件下促进植物生长的有前景的候选者。在本研究中，筛选了10株细菌分离株的吲哚-3-乙酸（IAA）产生情况，其中JTB1和MT22分离株在10%聚乙二醇（PEG）和2%氯化钠（NaCl）胁迫下产生高水平的IAA。这些分离株表现出高的解磷能力和1-氨基环丙烷-1-羧酸（ACC）脱氨酶活性。系统发育分析表明，JTB1和MT22分离株属于巨大芽孢杆菌。在中度和重度干旱胁迫下，将JTB1、MT22及其联合体作为PGPR施用显著促进了根系发育和甘蔗生长。在干旱胁迫下接种PGPR，甘蔗生长的促进源于活性氧（ROS）合成、丙二醛（MDA）、电解质渗漏和细胞损伤的延缓，这是通过增加抗氧化清除系统实现的，如过氧化氢酶（CAT）和抗坏血酸过氧化物酶（APX）。接种PGPR导致生长素转运蛋白表达增加，这调节了干旱胁迫下甘蔗中核酮糖-1,5-二磷酸羧化酶大亚基（RBC-L）、磷酸烯醇式丙酮酸羧化酶（PEPC）、蔗糖磷酸合酶（SPS）光合基因表达的增加。施用JTB1、MT22或它们的联合体对所有观察参数似乎都有相似的影响。总体而言，这些结果表明接种PGPR增强了根系发育，增加了抗氧化系统和光合活性，从而促进了干旱胁迫下甘蔗的生长。
