Abstract
BackgroundSoybean (Glycine max (L.) Merr. cv. “Nam Dan”) is one of the most valuable crops in agricultural production in Nghe An province (Vietnam). Our previous study revealed that extract of the cyanobacterium strain Nostoc calcicola HN9 expressed positive effect on growth and development, and raised soybean productivity (Tran et al. in Proceeding of Vietnam national conference of research on biology, Da Nang, 2016). We hypothesized that N. calcicola HN9 would improve the defense responses of G. max cv. “Nam Dan” to cowpea aphid (Aphis craccivora Koch)-a serious pest of leguminous crops.ResultsInfestation of A. craccivora caused oxidative stress in leaves of G. max cv. “Nam Dan”. A strong generation of endogenous reactive oxygen species (ROS) such as superoxide anion radical (O2·−) and hydrogen peroxide (H2O2) resulted in the cellular damages in the aphid-infested leaves through high levels of injury percentage and lipid peroxidation. To protect from aphid attack themselves, soybean plants triggered the antioxidant defense systems, in which, enzymatic antioxidants such as superoxide dismutase (SOD, 1.15.1.1), catalase (CAT, 1.11.1.6) and GPx (EC 1.11.1.9) were strongly accumulated to reduce the toxic effects of ROS. Components of N. calcicola HN9 extract might strengthen the defensive capability of G. max cv. “Nam Dan” to cowpea aphid infestation via establishing the chemical constraints on oxidative stress. Under effect of cyanobacteria extract, generation of O2·− and H2O2 was strictly limited, activities of SOD, CAT and GPx were remarkably accumulated in the aphid-infested leaves leading to a significant reduction of oxidative damages.ConclusionsNostoc calcicola HN9 extract probably not only controlled the generation and effects of O2·− and H2O2 but also augmented the accumulated activity of SOD, CAT and GPx in soybean leaves that allowed them to control oxidative stress, contributed to increase the resistance of G. max cv. “Nam Dan” to A. craccivora. The improvement of cyanobacteria extract on the antioxidative response of soybean “Nam Dan” to cowpea aphid can be a novel aspect to contribute to current knowledge regarding the soybean-aphid interaction.
Highlights
Cyanobacteria culture and extraction The cyanobacterium strain, N. calcicola HN9, was collected from the rice field in Hung Nguyen district (Nghe An province, Vietnam) and isolated by the streak plate method
Supernatant was collected after centrifuging by 10,000×g for 15 min, evaporated to obtain a crude brown gum. This gum was dissolved in the deionized water to the concentration of 0.03%, which expressed the positive effect to growth of soybean “Nam Dan” (Tran et al 2016)
Analysis of variance (ANOVA) results showed the significant difference in levels of O2·− in aphid-infested variants and control within 6–48 hpi
Summary
Our previous study revealed that extract of the cyanobacterium strain Nostoc calcicola HN9 expressed positive effect on growth and development, and raised soybean productivity (Tran et al in Proceeding of Vietnam national conference of research on biology, Da Nang, 2016). The endogenous substances in cyanobacteria, e.g., vitamins, enzymes, carbohydrates, amino acids, have been known to induce crop growth and raise yields (Shariatmadari et al 2013; Prasanna et al 2013). Other natural products from cyanobacteria like carotenoids, phenolic compounds, etc., exhibit various biological effects such as cytotoxic, antibacterial and antifungal activities (Kulik 1995; Zulpa et al 2003). Treating Solanum lycopersicum, Cucurbita maxima, Cucumis sativus plants with Nostoc calcicola extracts revealed a significant positive effect in most physiological examined factors (Shariatmadari et al 2011). An in vitro study of Li and co-workers (2007) demonstrated that Nostoc species have their ability to scavenge ROS and inhibit lipid peroxidation
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: 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.
