摘要：AbstractObjectivesAltica cyanea(Weber) (Coleoptera: Chrysomelidae) is a potential biocontrol agent of rice-field weeds,Ludwigia adscendens(L.) Hara,L. parvifloraRoxb., andL. octovalvis(Jacq.) Raven (Onagraceae) in India. Damage on leaf tissue causes stress on plants. Hence, this study aims to observe how the threeLudwigiaspecies are trying to cope with the stress caused by feeding ofA. cyaneaadults at different time intervals.MaterialsUninfestedL. adscendens,L. parviflora, andL. octovalvis, and eachLudwigiaspecies on which 5 adultA. cyaneafemales had fed on continuously for 6 h or 48 h were used for collection of leaf tissues. The amounts of total ROS, H2O2, activity of enzymatic antioxidants [superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), activity of peroxidases towards phenolic substances {guaiacol peroxidase (GPX) and pyrogallol peroxidase (PPX)}, and ascorbate peroxidase (APOX)] and non-enzymatic antioxidants (phenolics and thiols) were estimated from leaf tissues of undamaged and insect damagedLudwigiaspecies using standard protocols.ResultsThe amounts of total ROS and H2O2were higher in eachLudwigiaspecies after 48 h feeding byA. cyaneafollowed by plants after 6 h feeding byA. cyaneaand undamaged plants. The activities of antioxidant enzymes such as CAT, SOD, GST, APOX, PPX, and GPX were higher in eachLudwigiaspecies after 48 h feeding byA. cyaneacompared to undamaged plants. Total proteins and thiols were higher in each undamagedLudwigiaspecies compared to insect damaged plants; whereas total phenols were higher in each insect damagedLudwigiaspecies compared to undamaged plants.ConclusionsHigher amounts of total ROS and H2O2in each insect damagedLudwigiaspecies compared to undamaged plants suggested thatA. cyaneafeeding resulted stress in the insect damaged plants. Higher amounts of CAT, SOD, GST, and APOX in insect damagedLudwigiaspecies compared to undamaged plants suggested that these four enzymes were acting as antioxidants to reduce the stress created in plants due to insect herbivory.
关键词：Ludwigia adscendens;L. parviflora;L. octovalvis;Total ROS;H;2;O;2;Enzymatic and non-enzymatic antioxidants
