Prof. SUMERA ANWAR
Government College Women University, Pakistan
Title: ZnO/Nanobiochar Photocatalysis Degrades Polyethylene Microplastics and Ameliorates Growth, Physiological, and Antioxidant Responses in Cucumber (Cucumis sativus L.)
Abstract:
The accumulation of polyethylene microplastics (MP) in agroecosystem poses serious threat to plant health. This study evaluated the ameliorative potential of zinc oxide modified nanobiochar (ZnO/NB) through photocatalysis to degrade polyethylene MP and mitigate their phytotoxic effects on cucumber (Cucumis sativus L.) seedlings grown under Petri plate conditions. A completely randomized design was used five treatments: control (C), microplastic alone (MP), ZnO/NB alone as photocatalyst (PC), microplastics with ZnO/NB applied at sowing (MP+PC), and microplastics applied at sowing followed by ZnO/NB application after 3-5 days (MP→PC). Seedlings were monitored for 18 days, and germination indices, biomass, photosynthetic pigments, primary and secondary metabolites, and antioxidant enzyme activities were measured. UV-Vis spectrophotometry showed enhanced light absorption capacity of ZnO/NB, while fluorescence microscopy detected MPs residues in plant tissues. MP exposure reduced germination by 73%, impaired biomass accumulation, and increased oxidative damage. In contrast, PC treatment enhanced root length (3-fold), chlorophyll content (2-fold%), carotenoids (2-fold), soluble proteins (70%), and SOD activity (72%) compared with control. Both MP+PC and MP→PC alleviated MP-induced stress, improved the physiological parameters compared to MP alone, with MP→PC showed time-dependent detoxification with intermediate recovery. These preliminary findings showed that ZnO/NB- based photocatalysis can degrade microplastic and partially reverse their adverse effects. Future studies should investigate the photocatalytic potential of ZnO/NB under soil conditions as an eco-compatible strategy to mitigate microplastic toxicity through degradation.
Keywords: Polyethylene microplastics; Zinc oxide modified nanobiochar; Photocatalysis; Phytotoxicity; Cucumber (Cucumis sativus L.); Oxidative stress amelioration
Biography:
Dr. Sumera Anwar is an Associate Professor in the Department of Botany at Government College Women University, Faisalabad, Pakistan. She earned her PhD in Botany from the University of Agriculture, Faisalabad, and completed postdoctoral research at Durham University in the UK and Huazhong Agricultural University in China. Her research focuses on plant stress physiology, water and nutrient use efficiency, soil-plant interactions, and phytoremediation. She has published over 160 peer-reviewed SCI papers with a cumulative impact factor of 436. Dr. Anwar has received multiple international fellowships, including the Talented Young Scientist Program from China's Ministry of Science and Technology. She serves as a Review Editor for Frontiers in Plant Nutrition and Frontiers in Agronomy, and regularly peer-reviews for several leading journals. Her work bridges fundamental plant science with real-world sustainable agricultural applications.