Abstract
Cucumis sativus L. seedlings were pretreated 1 h with 10 μM paraquat (PQ) and then were subjected to normal (25/18 °C) or elevated (42/38 °C) temperature to investigate whether PQ can protect plants against heat stress. Heat stress inhibited fresh and dry masses of the second leaf, root dry mass and shoot fresh mass. In leaves, the stress disintegrated membranes of 84.97 % chloroplasts and elevated contents of malondialdehyde, superoxide radical and hydrogen peroxide. In contrast, PQ pretreatment altered antioxidant activities in leaves, even after PQ was rinsed off before seedlings were exposed to different temperatures. Under heat stress, PQ pretreatment improved plant growth, decreased percentage of abnormal chloroplasts (53.03 %) and reduced contents of malonaldehyde, superoxide radical and hydrogen peroxide due to increased activities of antioxidant enzymes such as superoxide dismutase, catalase, guaiacol peroxidase, glutathione peroxidase, ascorbate peroxidase, monodehydroascorbate reductase, dehydroascorbate reductase and glutathione reductase.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.