Majhi Basudev, Semwal Pradeep, Mishra Shashank Kumar, Misra Sankalp, Chauhan Puneet Singh
Microbial Technologies Division, Council of Scientific and Industrial Research-National Botanical Research Institute (CSIR-NBRI), Rana Pratap Marg, Lucknow, 226001, India.
Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India.
Int Microbiol. 2025 May;28(Suppl 1):11-25. doi: 10.1007/s10123-023-00447-w. Epub 2023 Nov 18.
Arsenic (As) contamination is a major problem affecting soil and groundwater in India, harming agricultural crops and human health. Plant growth-promoting rhizobacteria (PGPR) have emerged as promising agents for reducing As toxicity in plants. This study aimed to isolate and characterize As-tolerant PGPR from rice field soils with varying As levels in five districts of West Bengal, India. A total of 663 bacterial isolates were obtained from the different soil samples, and 10 bacterial strains were selected based on their arsenite (As-III) and arsenate (As-V) tolerant ability and multiple PGP traits, including phosphate solubilization, production of siderophore, indole acetic acid, biofilm formation, alginate, and exopolysaccharide. These isolates were identified by 16S rRNA gene sequencing analysis as Staphylococcus sp. (4), Niallia sp. (2), Priestia sp. (1), Bacillus sp. (1), Pseudomonas sp. (1), and Citricoccus sp. (1). Among the selected bacterial strains, Priestia flexa NBRI4As1 and Pseudomonas chengduensis NBRI12As1 demonstrated significant improvement in rice growth by alleviating arsenic stress under greenhouse conditions. Both strains were also able to modulate photosynthetic pigments, soluble sugar content, proline concentration, and defense enzyme activity. Reduction in As-V accumulation inoculated with NBRI4As1 was recorded highest by 53.02% and 31.48%, while As-III by NBRI12As1 38.84% and 35.98% in the roots and shoots of rice plants, respectively. Overall, this study can lead to developing efficient As-tolerant bacterial strains-based bioinoculant application packages for arsenic stress management in rice.
砷（As）污染是影响印度土壤和地下水的一个主要问题，对农作物和人类健康造成危害。植物促生根际细菌（PGPR）已成为降低植物中砷毒性的有前景的媒介。本研究旨在从印度西孟加拉邦五个地区不同砷含量的稻田土壤中分离和鉴定耐砷PGPR。从不同土壤样品中总共获得了663株细菌分离物，并根据它们对亚砷酸盐（As-III）和砷酸盐（As-V）的耐受能力以及多种植物促生特性（包括磷酸盐溶解、铁载体产生、吲哚乙酸、生物膜形成[1]、藻酸盐和胞外多糖）选择了10株细菌菌株。通过16S rRNA基因测序分析将这些分离物鉴定为葡萄球菌属（4株）、尼尔利亚菌属（2株）、Priestia菌属（1株）、芽孢杆菌属（1株）、假单胞菌属（1株）和柠檬酸球菌属（1株）。在所选细菌菌株中，Flexibacterium flexa NBRI4As1和成都假单胞菌NBRI12As1在温室条件下通过减轻砷胁迫显著促进了水稻生长。这两种菌株还能够调节光合色素、可溶性糖含量、脯氨酸浓度和防御酶活性。接种NBRI4As1后，水稻植株根和茎中As-V积累的减少分别高达53.02%和31.48%，而接种NBRI12As1后As-III积累的减少分别为38.84%和35.98%。总体而言，本研究可为开发基于高效耐砷细菌菌株的生物接种剂应用包以管理水稻中的砷胁迫奠定基础。
