The maize SUMO conjugating enzyme ZmSCE1b protects plants from paraquat toxicity

• Published in: Ecotoxicology and environmental safety Vol. 211; p. 111909
• Main Authors: Wang, Huanyan, Xu, Dongliang, Zhu, Xianfeng, Wang, Meiping, Xia, Zongliang
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Inc 15.03.2021; Elsevier
• Subjects: Antioxidant enzyme; Antioxidants - metabolism; Arabidopsis - metabolism; Herbicides - metabolism; Herbicides - toxicity; Lipid Peroxidation; Maize; Paraquat - toxicity; Paraquat resistance; Plant Proteins - metabolism; Plants, Genetically Modified - metabolism; Protective Agents - metabolism; Reactive Oxygen Species - metabolism; SUMOylation; Sumoylation - physiology; Up-Regulation; Zea mays - enzymology; Zea mays - metabolism; Maize; Paraquat resistance; SUMOylation; Antioxidant enzyme
• ISSN: 0147-6513; 1090-2414
• DOI: 10.1016/j.ecoenv.2021.111909

Paraquat (PQ) herbicide causes damage to green plant tissues by inducing the production of toxic reactive oxygen species (ROS). SUMOylation is an important post-translational modification that enables plants to defend against multiple stresses. However, it is still unknown whether the SUMOylation is involved in PQ resistance response in crops. Herein, we showed that a maize SUMO conjugating enzyme gene (ZmSCE1b) functioned in PQ resistance. The quantitative real-time PCR (qRT-PCR) analysis revealed that this gene was significantly up-regulated upon PQ exposure. The overexpression of ZmSCE1b increased the levels of SUMO conjugates and improved PQ resistance in transgenic Arabidopsis. The ZmSCE1b-transgenic plants showed lower levels of ROS and lipid peroxidation, as well as higher antioxidant enzyme activities, upon PQ exposure. Furthermore, Western blotting showed that levels of SUMOylation in these transgenic plants were significantly elevated. In addition, the abundance of transcripts of several defense-related genes was apparently up-regulated in the over-expressing lines using qRT-PCR. Collectively, our results manifested the effect of overexpression of ZmSCE1b in improving resistance to PQ, possibly by regulating the levels of SUMO conjugates, antioxidant machinery, and expression of defense genes. Findings of this study can facilitate the understanding of the regulatory mechanisms underlying the involvement of SCE-mediated SUMOylation in PQ resistance response in crop plants. Meanwhile, ZmSCE1b could be utilized for engineering PQ-resistant crops in phytoremediation. •ZmSCE1b was significantly up-regulated upon paraquat (PQ) exposure.•Over-expression of ZmSCE1b in Arabidopsis increased levels of SUMO conjugates and enhanced PQ resistance.•ZmSCE1b-transgenic plants had higher antioxidant capability, showing lower ROS and MDA accumulations upon PQ exposure.•Expression of several defense genes was significantly elevated in these transgenic lines upon PQ exposure.•ZmSCE1b could be utilized for engineering PQ-resistant crops in phytoremediation.