Department of Botanical and Environmental Sciences, Guru Nanak Dev University, Amritsar 143005, India.
Department of Zoology, Guru Nanak Dev University, Amritsar 143005, India.
Biomolecules. 2019 Oct 7;9(10):581. doi: 10.3390/biom9100581.
Environmental stress including heavy metal pollution is increasing at high speed and is polluting the cultivable land. Consequently, it results in affecting human population through entering into food chain. The current study aims that Cd stress (0.4 mM) led to toxicity and deleterious effects on 45-day-old plants. The use of rhizobacterial strains underlines the main hypothesis of the present research that have been exploited in order to alleviate the Cd induced stress in plants and promoting their growth sidewise. The morphological parameters, plant pigments, and gaseous exchange parameters were estimated and found to be reduced in plants due to Cd toxicity. Along with this, the levels of phenolic compounds and osmoprotectants were stimulated in plants raised in Cd spiked soils. In addition, free amino acid content was reduced in plants under Cd treatment. It was revealed that these bacterial strains (M1) and (M2) when inoculated to tomato plants improved the morphological characteristics and enhanced photosynthetic attributes. Moreover, the level of phenolic compounds and osmoprotectants were further enhanced by both the inoculating agents independently. However, in situ localization studies of phenol accumulation in root sections was found to be enhanced in Cd treated plants as revealed through higher intensity of yellowish-brown colour. The supplementation of bacterial strains further accumulated the phenols in Cd stressed root sections as evidenced through increased colour intensity. Therefore, the present study suggested that bacterial strains mitigates Cd stress from tomato plants through improving morphological, physiological and metabolite profiles. Consequently, the present research advocates the best utilization of rhizobacteria as stress alleviators for sustainable agriculture.
环境压力包括重金属污染正在高速增加，并污染着可耕地。因此，它通过进入食物链影响人类种群。本研究旨在研究 Cd 胁迫（0.4mM）对 45 天大的植物的毒性和有害影响。根际细菌菌株的使用强调了本研究的主要假设，即已经利用这些菌株来减轻植物中的 Cd 诱导应激，并促进它们的生长。估计了形态参数、植物色素和气体交换参数，发现由于 Cd 毒性，这些参数在植物中降低。此外，在添加 Cd 的土壤中生长的植物中刺激了酚类化合物和渗透保护剂的水平。此外，在 Cd 处理下，植物中的游离氨基酸含量减少。结果表明，这些细菌菌株（M1）和（M2）接种到番茄植物中可以改善形态特征并增强光合作用特性。此外，两种接种剂都可以独立地进一步提高酚类化合物和渗透保护剂的水平。然而，通过原位定位研究发现，在 Cd 处理的植物中，根段中酚类化合物的积累增加，表现为黄色-棕色的颜色强度增加。细菌菌株的补充进一步增加了 Cd 胁迫根段中的酚类物质，表现为颜色强度增加。因此，本研究表明，细菌菌株通过改善形态、生理和代谢特征来减轻番茄植物中的 Cd 胁迫。因此，本研究提倡最好利用根际细菌作为可持续农业的应激缓解剂。
