Transcriptomic and metabolomic responses of maize under conventional and biodegradable microplastic stress

• Published in: iMetaOmics (Print) 2025-03, Vol.2 (1), p.n/a
• Main Authors: Sun, Yuanze, Zang, Jingxi, Xie, Siyuan, Wu, Mochen, Tao, Jianguo, Adyel, Tanveer M., Du, Xinyu, Li, Si, Wang, Jie
• Format: Article
• Language: English
• Subjects: biodegradable microplastics; chemical defense; conventional microplastics; DOM; maize; multi‐omics; rhizosphere microorganisms
• ISSN: 2996-9506; 2996-9514
• DOI: 10.1002/imo2.48

The increasing accumulation of microplastics in agricultural soils potentially threatens crop safety and quality. However, studies regarding the molecular mechanisms underlying the effects of conventional and biodegradable microplastics on plant growth remain limited. Herein, we estimated the effects of biodegradable polybutylene adipate terephthalate, poly (butylene succinate), polylactic acid, and conventional non‐biodegradable polyethylene and polystyrene microplastics (at a concentration of 1% [w/w]) on the growth and physiological performance of maize (Zea mays L.). In addition, we studied the molecular mechanisms underlying the effects of these microplastics on maize. Exposure to microplastics induced the production of antioxidant enzymes and antioxidants at varying levels in the maize. While the maize antioxidant systems were induced against biodegradable microplastic exposure, maize photosynthesis was relatively more important for conventional microplastic treatments. Additionally, metabolomics and transcriptomic analyses revealed that the pathways of secondary metabolite biosynthesis, photosynthesis, energy metabolism, and carbohydrate metabolism were regulated by biodegradable and conventional microplastics. Specifically, microplastics induced the plant hormone signal transduction and mitogen‐activated protein kinase signaling pathways. Our results further indicated that microplastics could impact the plant through changing the soil environmental variables or altering the soil microbial communities. This study provides a molecular‐scale perspective on the responses of crops to microplastic contamination, and these findings will contribute to the ecological risk assessment of biodegradable and conventional microplastics. This study revealed that microplastics activated the antioxidant defense system and enhanced maize photosynthesis. Metabolomic and transcriptomic analyses showed that biodegradable and conventional microplastics regulated pathways related to secondary metabolite biosynthesis and carbohydrate metabolism. Belowground changes played a key role in mediating maize responses to microplastic stress. Highlights Microplastics triggered antioxidant defense system, especially under biodegradable microplastic exposure. Microplastic exposure induced the plant hormone signal transduction and mitogen‐activated protein kinase signaling pathways. Effects of microplastics on plants resulted from changing the soil environmental variables or altering