Abstract
Contamination of soil and water with metals and metalloids is one of the most serious problems worldwide due to a lack of a healthy diet and food scarcity. Moreover, the cultivation of oilseed crops such as rapeseed (Brassica napus L.) with tannery wastewater could contain a large amount of toxic heavy metals [e.g., chromium (Cr)], which ultimately reduce its yield and directly influence oilseed quality. To overcome Cr toxicity in B. napus, a pot experiment was conducted to enhance plant growth and biomass by using newly introduced role of micronutrient-amino chelates [Zinc-lysine (Zn-lys)], which was irrigated with different levels [0% (control), 33%, 66%, and 100%] of tannery wastewater. According to the results of present findings, very high content of Cr in the wastewater directly affected plant growth and composition as well as gas exchange parameters, while boosting up the production of reactive oxygen species (ROS) and induced oxidative damage in the roots and leaves of B. napus. However, activities of antioxidants initially increased (33% of wastewater), but further addition of tannery wastewater in the soil caused a decrease in antioxidant enzymes, which also manifested by Zn content, while the conscious addition of wastewater significantly increased Cr content in the roots and shoots of B. napus. To reduce Cr toxicity in B. napus plants, exogenous supplementation of Zn-lys (10 mg/L) plays an effective role in increasing morpho-physiological attributes of B. napus and also reduces the oxidative stress in the roots and leaves of the oilseed crop (B. napus). Enhancement in different growth attributes was directly linked with increased in antioxidative enzymes while decreased uptake and accumulation of Cr content in B. napus when cultivated in wastewater with the application of Zn-lys. Zn-lys, therefore, plays a protective role in reducing the Cr toxicity of B. napus through an increase in plant growth and lowering of Cr uptake in various plant organs. However, further studies at field levels are required to explore the mechanisms of Zn–lys mediated reduction of Cr and possibly other heavy metal toxicity in plants.
Highlights
The rapid industrial and urbanization caused by the population’s overly growing threat posed a threat to humanity by air, water, and land contamination with different heavy metals [1]
Maximum decreased in plant height, the number of leaves, leaf area, root length, fresh root weight, root dry weight, fresh leaf weight, dry leaf weight by 68.6%, 54.5%, 84.5%, 38.4%, 89.7%, 89.5%, 78.6%, and 82.3%, respectively, in T6 plants
The data regarding (T7) were statistically non-significant with (T6), which was showing that the application of Zn-lys at 100% wastewater level did not significantly affect the plant growth and biomass in B. napus
Summary
The rapid industrial and urbanization caused by the population’s overly growing threat posed a threat to humanity by air, water, and land contamination with different heavy metals [1]. Due to the scarcity of fresh water, wastewater cultivation became a common practice in arid and semi-arid areas, which has serious impacts on plants and human health [3]. The two major cities with a large number of tanneries in Pakistan are Sialkot and Kasur In these areas, different factories emit large amounts of untreated wastewater and contaminate the region’s freshwater resources [4]. Pakistan is facing a severe shortage of fresh water due to a large number of factories and manufacturers, and farmers often use industrial wastewater to cultivate fields [2]. Excess Cr has been caused by the generation of extreme amounts of reactive oxygen species (ROS)
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call