Danish Mohammad, Shahid Mohammad, Shafi Zaryab, Farah Mohammad Abul, Al-Anazi Khalid Mashay
Botany Section, School of Sciences, Maulana Azad National Urdu University, Hyderabad, India.
Department of Agricultural Microbiology, Faculty of Agriculture Sciences, Aligarh Muslim University, Aligarh, U.P, 202002, India.
World J Microbiol Biotechnol. 2025 Jan 11;41(2):34. doi: 10.1007/s11274-024-04239-w.
Utilizing metal/nanoparticle (NP)- tolerant plant growth-promoting rhizobacteria (PGPR) is a sustainable and eco-friendly approach for remediation of NP-induced phytotoxicity. Here, Pisum sativum (L.) plants co-cultivated with different CuO-NP concentrations exhibited reduced growth, leaf pigments, yield attributes, and increased oxidative stress levels. Cu-tolerant (800 µM) Klebsiella variicola strain SRB-4 (Accession no. OR715781.1) recovered from metal-contaminated soils produced various PGP traits, including IAA, EPS, siderophore, HCN, ammonia, and solubilized insoluble P. The PGP substances were marginally increased with increasing CuO-NP concentrations. When applied, Cu-tolerant SRB-4 strain increased root length (18%), root biomass (15.3%), total chlorophyll (29%), carotenoids (30%), root N (21%), root P (23%), total soluble protein (20%) nodule number (32%), nodule biomass (39%) and leghaemoglobin content (18%) in 50 µM CuO-NP-exposed peas. Furthermore, proline, malondialdehyde (MDA), superoxide radical, hydrogen peroxide (HO) content, and membrane injury in K. variicola-inoculated and 50 µM CuO-NP-treated plants were maximally and significantly (p ≤ 0.05) reduced by 70.6, 26.8, 60.8, and 71.6%, respectively, over uninoculated but treated with similar NP doses. Moreover, K. variicola inoculation caused a significant (p ≤ 0.05) decline in Cu uptake in roots (71%), shoots (65.5%), and grains (76.4%) of peas grown in soil contaminated with 50 µM CuO-NP. The multivariate i.e. heat map and pearson correlation analyses between the NP-treated and PGPR inoculated parameters revealed a significant and strong positive corelation. The NP-tolerant indigenous beneficial K. variicola could be applied as an alternative to enhance the production of P. sativum cultivated in nano-polluted soil systems. Additionally, more investigation is required to ascertain the seed/soil inoculation effect of K. variicola SRB-4 on soil biological activities and different crops under various experimental setups.
利用耐金属/纳米颗粒（NP）的植物促生根际细菌（PGPR）是修复NP诱导的植物毒性的一种可持续且环保的方法。在此，与不同浓度CuO-NP共同培养的豌豆（Pisum sativum (L.)）植株生长减缓、叶片色素含量降低、产量属性下降，且氧化应激水平升高。从金属污染土壤中分离出的耐铜（800 µM）肺炎克雷伯氏菌菌株SRB-4（登录号OR715781.1）表现出多种植物促生特性，包括吲哚乙酸（IAA）、胞外多糖（EPS）、铁载体、HCN、氨以及溶解不溶性磷。随着CuO-NP浓度增加，这些植物促生物质略有增加。在50 µM CuO-NP处理的豌豆中，接种耐铜SRB-4菌株后，根长增加了18%，根生物量增加了15.3%，总叶绿素增加了29%，类胡萝卜素增加了30%，根氮增加了21%，根磷增加了23%，总可溶性蛋白增加了20%，根瘤数增加了32%，根瘤生物量增加了39%，豆血红蛋白含量增加了18%。此外，接种肺炎克雷伯氏菌且经50 µM CuO-NP处理的植株中，脯氨酸、丙二醛（MDA）、超氧自由基、过氧化氢（H₂O₂）含量以及膜损伤分别比未接种但接受相似NP剂量处理的植株最大且显著（p≤0.05）降低了70.6%、26.8%、60.8%和71.6%。此外，接种肺炎克雷伯氏菌使生长在受50 µM CuO-NP污染土壤中的豌豆根、茎和籽粒中的铜吸收量分别显著（p≤0.05）下降了71%、65.5%和76.4%。NP处理参数与PGPR接种参数之间的多变量分析，即热图分析和皮尔逊相关性分析显示存在显著且强烈的正相关。耐NP的本土有益菌肺炎克雷伯氏菌可作为一种替代方法，用于提高在纳米污染土壤系统中种植的豌豆的产量。此外，还需要更多研究来确定肺炎克雷伯氏菌SRB-4的种子/土壤接种对不同实验设置下土壤生物活性和不同作物的影响。
