Abstract

The present study was intended to assess the potential of iron oxide nanoparticles (IONPs) and Bacillus subtilis S4 in mitigation of arsenic (As) stress in Cucurbita moschata. Cucurbita moschata seedlings were subjected to As stress for 60 days. Reduced level of growth parameters including photosynthetic pigments, rate of photosynthesis and gas exchange characteristics was observed in seedlings subjected to As stress. However, IONPs and B. subtilis S4 improved growth attributes and proline contents in supplemented C. moschata seedlings. Bacillus subtilis S4 inoculated seedlings showed higher activity of peroxidase (POD) and superoxide dismutase (SOD) under As toxicity. Similarly, the co-application of IONPs and B. subtilis S4 further increased the activity of these antioxidative enzymes. The As stress alleviation in inoculated C. moschata seedlings is credited to reduced levels of hydrogen peroxide (H₂O₂), malondialdehyde (MDA) and electrolyte leakage (EL) in IONPs and B. subtilis S4-treated plants. Furthermore, synergism between plant growth promoting bacteria (PGPB) and IONPs enhanced the biosynthesis of stress mitigating polyamines including spermidine and putrescine in As-stressed seedlings. Current research reveals that synergistic application of IONPs and B. subtilis S4 is an effective sustainable and ecofriendly approach for alleviation of As stress in C. moschata seedlings.

摘要

本研究的目的是评估氧化铁纳米粒子（IONPs）和潜在的枯草芽孢杆菌S4在砷（As）应力缓解南瓜。将南瓜子幼苗置于As胁迫下60天。在砷胁迫下，幼苗的生长参数水平下降，包括光合色素，光合作用速率和气体交换特性。然而，IONPs和枯草芽孢杆菌S4改善了补充的C. moschata幼苗的生长特性和脯氨酸含量。枯草芽孢杆菌接种S4的幼苗在As毒性下表现出较高的过氧化物酶（POD）和超氧化物歧化酶（SOD）活性。类似地，IONPs和枯草芽孢杆菌S4的共同应用进一步提高了这些抗氧化酶的活性。在接种作为应力缓和C.南瓜幼苗贷记过氧化氢（H水平降低₂ ö ₂在IONPs和），丙二醛（MDA）和电解质渗漏（EL）的枯草芽孢杆菌经S4处理的植物。此外，植物生长促进细菌（PGPB）与IONP之间的协同作用增强了胁迫胁迫幼苗中缓解胁迫的多胺（包括亚精胺和腐胺）的生物合成。目前的研究表明IONPs的是协同应用和枯草芽孢杆菌S4是在作为压力减轻的有效的可持续和环保的方法C.南瓜苗。