C. G. Bhakta Institute of Biotechnology, Uka Tarsadia University, Maliba Campus, Bardoli, Surat, Gujarat, 394350, India.
Pandit Deendayal Upadhyay College of Horticulture & Forestry, Dr. Rajendra Prasad Central Agricultural University, Tirhut College Campus, Muzaffarpur, Bihar, 843121, India.
Environ Sci Pollut Res Int. 2021 Feb;28(6):6540-6548. doi: 10.1007/s11356-020-10998-4. Epub 2020 Sep 30.
Soil contamination by heavy metals is one of the major abiotic stresses that cause retarded plant growth and low productivity. Among the heavy metals, excessive accumulations of zinc (Zn) cause toxicity to plants. The toxicity caused by Zn could be managed by application of Zn-tolerant plant growth-promoting (PGP) bacteria. In this study, five Zn-tolerant bacteria (100-400 mg Zn resistant) were selected and identified as Lysinibacillus spp. based on 16S rRNA gene sequencing. The PGP properties of the Lysinibacillus spp. showed the production of indole acetic acid (60.0-84.0 μg/ml) and siderophore, as well as solubilization of potassium. Furthermore, the isolates were evaluated under greenhouse condition with 2 g kg Zn stress and without Zn stress along with control on Zea mays. The results showed that Lysinibacillus spp. coated seeds enhanced plant growth attributes and biomass yield in both conditions compared with control plants. The enhancement of root growth ranged from 49.2 to 148.6% and shoot length from 83.3 to 111.7% under Zn-stressed soils. Also, the inoculated seedlings substantially enhanced chlorophyll a and b, proline, total phenol, and ascorbic acid. The uptake of Zn by maize root ranged from 31.5 to 210.0% compared with control plants. Therefore, this study suggested that the tested Zn-tolerant Lysinibacillus spp. may be used for cultivation of Z. mays in Zn-contaminated agricultural lands.
土壤重金属污染是导致植物生长缓慢和生产力低下的主要非生物胁迫因素之一。在重金属中，过量积累的锌（Zn）会对植物产生毒性。锌的毒性可以通过应用耐锌植物促生（PGP）细菌来控制。在这项研究中，根据 16S rRNA 基因测序，选择并鉴定了 5 株耐锌细菌（100-400mg Zn 抗性）为Lysinibacillus spp。Lysinibacillus spp 的 PGP 特性表现为吲哚乙酸（60.0-84.0μg/ml）和铁载体的产生，以及钾的溶解。此外，在温室条件下，用 2gkg Zn 胁迫和无 Zn 胁迫以及对照处理玉米（Zea mays）对分离株进行了评价。结果表明，与对照植物相比，Lysinibacillus spp. 包被种子在两种条件下都能增强植物的生长特性和生物量产量。在 Zn 胁迫土壤中，根生长的增强幅度为 49.2%至 148.6%，茎长的增强幅度为 83.3%至 111.7%。此外，接种幼苗显著提高了叶绿素 a 和 b、脯氨酸、总酚和抗坏血酸的含量。与对照植物相比，玉米根对 Zn 的吸收量增加了 31.5%至 210.0%。因此，本研究表明，所测试的耐锌Lysinibacillus spp. 可用于在 Zn 污染的农田中种植玉米。
