By: Bangshidhar Goswami
Ex-Assistant Professor, Department of Metallurgical Engineering,
Ran Vijay Singh College of Engineering and Technology,
Jamshedpur, East-Singhbhum, Jharkhand, India
This study investigates heavy metal uptake, tolerance, and sequestration mechanisms in various plants, focusing on crops such as tea, vegetables, and fruit trees that are susceptible to heavy metal contamination. Trace elements in plants, if overabundant, pose toxicity risks by disrupting metabolic and physiological functions. Plants counteract heavy metal complexes by immobilizing them within cell walls or vacuoles or by binding them to organic compounds produced in situ. Elevated levels of reactive oxygen species (ROS) are often a byproduct, triggering oxidative stress that impacts plant homeostasis and cellular integrity. This stress response involves pro-oxidant and antioxidant imbalance, along with changes in enzymatic functions that affect oxygen activation, hydrogen peroxide production, and the release of defensive compounds like methylglyoxal. Seasonal and incidental contaminations vary by location and soil type, influencing the distribution of heavy metals between roots, stems, and leaves. Techniques such as chelation, compartmentalization, and symbiotic interactions with mycorrhizal fungi are highlighted for their roles in reducing metal uptake. Analytical studies reveal that plant-derived substances like metallothioneins, phytochelatins, polysaccharides, and organic acids significantly mediate heavy metal immobilization. Given the long biological half-life of heavy metals in human tissues, the cumulative effects of consuming contaminated plant products require monitoring, particularly in consumer staples like tea. Findings underscore the need for stringent quality control measures and adaptive agricultural practices to mitigate heavy metal accumulation in edible plants, thus protecting human health and preserving soil quality.
Citation:
Refrences:
- Xi-bai ZENG, Lian-fang LI & Xu-rong ME (2008). Heavy Metal Content in Chinese Vegetable Plantation Land Soils and Related Source Analysi. Agricultural Sciences in China, 7(9), 1115.
- Zhongchen Hu, Jianwu Li, Hailong Wang, Zhengqian Ye, Xudong Wang, Yongfu Li, Dan Liu & Zhaoliang Song (2019). Soil Contamination with Heavy Metals and Its Impact on Food Security in China, Journal of Geoscience and Environment Protection, 7(5), 168-183, Available at https://www.scirp.org/journal/paperinformation.aspx?paperid=92760.
- Wan Noni Afida Ab Manan, Fazrul Razman Sulaiman, Rubaiyah Alias & Rusdin Laiman (2018). Determination of Selected Heavy Metal Concentrations in an Oil Palm Plantation Soil. Journal of Physical Science, 29(3), 63–70, Available at https://www.researchgate.net/publication/328454645_Determination_of_Selected_Heavy_Metal_Concentrations_in_an_Oil_Palm_Plantation_Soil.
- Fonge, B. A., Nkoleka, E. N., Asong, F. Z., Ajonina, S. A. & Che, V. B. (2017). Heavy metal contamination in soils from a municipal landfill, surrounded by banana plantation in the eastern flank of Mount Cameroon. African Journal of Biotechnology, 16(25), 1391-1399, Available at https://academicjournals.org/journal/AJB/article-abstract/0FAA49864868.
- Harunur Rashid, Zeenath Fardous, M. Alamgir, Zaman Chowdhury, Khorshed Alam, Latiful Bari, Mohammed Moniruzzaman & Siew Hua Gan (2016). Determination of heavy metals in the soils of tea plantations and in fresh and processed tea leaves: an evaluation of six digestion methods. Chemistry Central Journal, 10(7), Available at https://pubmed.ncbi.nlm.nih.gov/26900397.
- Mingkui Zhang & Liping Fang (2007). Tea Plantation–Induced Activation of Soil Heavy Metals. Communications in Soil Science and Plant Analysis, 38(11-12), 1467-1478,
- Marius Praspaliauskas, Nerijus Pedisius & Audrius Gradeckas (2018). Accumulation of heavy metals in stemwood of forest tree plantations fertilized with different sewage sludge doses. Journal of Forestry Research, 29(2), 347–361.
- Khairiah Jusoh, Y. Ding-Woei, Habibah Jamil, R. Ahmad-Mahir, A. Aminah & B.S. Ismail (2009). Concentration of heavy metals in guava plants and soil in the Sungai Wangi plantation, Perak, Malaysia. International Journal of Agricultural Research, 4(10), 310-316, Available at https://www.researchgate.net/publication/250302960_Concentration_of_Heavy_Metals_in_Guava_Plant_Parts_and_Soil_in_the_Sungai_Wangi_Plantation_Perak_Malaysia.
- Zul Arham, La Ode Asmin, Rosmini & Muhammad Nurdin (2017). Heavy Metal Content of Cocoa Plantation Soil in East Kolaka, Indonesia. Oriental Journal of Chemistry, 33(3), 1164-1170, Available at http://www.orientjchem.org/vol33no3/heavy-metal-content-of-cocoa-plantation-soil-in-east-kolaka-indonesia/.
- Abolghassem Emamverdian, Yulong Ding, Farzad Mokhberdoran & Yinfeng Xie, (2015). Heavy Metal Stress and Some Mechanisms of Plant Defense Response. The Scientific World Journal, Available at https://www.hindawi.com/journals/tswj/2015/756120/.
- Katrin Viehweger (2014). How plants cope with heavy metals. Botanical Studies, 55(35), pp. 1-12, Available at: https://as-botanicalstudies.springeropen.com/articles/10.1186/1999-3110-55-35.
