SUBALA S P
@anjaconine.org
Assistant Pprofessor & Department of Biotechnology
Ayya nadar Janaki Ammal College
RESEARCH, TEACHING, or OTHER INTERESTS
Agricultural and Biological Sciences, Biotechnology, General Agricultural and Biological Sciences, Insect Science
Scopus Publications
Scopus Publications
Perumal Vivekanandhan, Tahani Awad Alahmadi, Mohammad Javed Ansari, and S. P. Subala
Frontiers Media SA
Chemical insecticides are effective at controlling mosquito populations, but their excessive use can pollute the environment and harm non-target organisms. Mosquitoes can also develop resistance to these chemicals over time, which makes long-term mosquito control efforts challenging. In this study, we assessed the phytochemical, biochemical, and insecticidal properties of the chemical constituents of cajeput oil. Results show that Melaleuca cajuputi essential oil may exhibit mosquito larvicidal properties against Anopheles stephensi larvae (second-fourth instar) at 24 h post-treatment. At 24 h post-exposure, the essential oil resulted in a significant decrease in detoxifying enzymes. All of these findings indicate that cajeput oil infects An. stephensi larvae directly affect the immune system, leading to decreased immune function. Cajeput oil significantly affects the second, third, and fourth instar larvae of An. stephensi, according to the bioassay results. Cajeput oil does not induce toxicity in non-target Eudrilus eugeniae earthworm species, as indicated by a histological study of earthworms. Phytochemical screening and GC-MS analysis of the essential oil revealed the presence of several major phytochemicals that contribute to mosquito larvicidal activity. The importance of cajeput oil as an effective candidate for biological control of the malarial vector An. stephensi is supported by this study.
Perumal Vivekanandhan, Kannan Swathy, Lucy Alford, Sarayut Pittarate, Subramanian Panchu Ravindra Rajan Subala, Supamit Mekchay, Dilipan Elangovan, and Patcharin Krutmuang
Springer Science and Business Media LLC
AbstractInsect pests of agricultural crops have establish immunological tolerance against fungal infection caused by pathogens via different humoral and cellular processes. Fungal infection can be prevented by insect antioxidant and detoxifying enzymes, but there is no clear understanding of how they physiologically and biochemically interact. Our study aims to examine the antioxidant and detoxifying enzyme defense systems of the pest insectSpodoptera liturain response to infection byMetarhizium flavoviride. At 48 h following exposure toM. flavoviride, antioxidant enzyme levels were modified, and phenoloxidase and total hemocyte count were decreased significantly. The amount of detoxifying enzymes increased significantly.M. flavovirideappears to directly affect theS. lituraimmune system and results in decreased immunity. In a bioassay,M. flavoviridewas found to be harmful toS. lituralarvae in their third and fourth instar stage. M. flavoviridemay be an effective tool in the control ofS. lituralarvae. Such entomopathogenic fungi represent cheaper, pollution free, target specific, promising alternatives to synthetic chemical tools in the for control insect pests.
Govindaraj Vengateswari, Subramanian Panchuravindra Rajan Subala, and Muthugounder Subramanian Shivakumar
Informa UK Limited
ABSTRACT In vertebrates, many studies verified the immunomodulatory effect of melatonin in various tissues. Its exact role in lower organisms like insects has been very sketchy. The present study deals with understanding the immunomodulatory effect of melatonin in pesticide exposed insects. Total hemocyte count, Differential hemocyte count, Prophenoloxidase activity, and nodulation mechanism at different time intervals were studied. Results showed the abamectin results in significant increase (p < 0.01) in haemocytes numbers at 6, 48, and 72 h. Abamectin toxicity was counteracted by melatonin, with decreasing the hemocytes at 2, 4, and 12 h. Prophenoloxidase activity and protein content (p < 0.001) at 48 and 72 h of Melatonin + abamectin were slightly decreased. There was a significant decrease in nodule formation in 12–24 h in melatonin treated groups and it was clearly visible at 6 h. Increased Prohemocytes, Plasmatocytes, and Oenocytoids numbers decline in melatonin treatment. Melatonin treatment increased the survival rate on pesticide exposed insects. Results suggest that melatonin exposure significantly reduces the toxicity in pesticide exposed larvae which in turn brings back immunological profile in a time dependent manner.
Subramanian Panchu Ravindra Rajan Subala and Muthugounder Subramanian Shivakumar
Informa UK Limited
Abstract The present study was conducted to describe the impact of circadian rhythm on melatonin levels and redox statusunder three photoperiods (12L:12D, 0L:24D, and 24L:0D) in head and hemolymph of Spodoptera litura. Melatonin is an powerful antioxidant and controls the reproduction of organisms. In this study, melatonin levels, Arylalkylamine N-acetyltransferase(AA-NAT), and antioxidant enzyme activities were analyzed. Results showed melatonin, AA-NAT levels in hemolymph were significantly (p < 0.05) higher during the dark period than during LL regime. HPLC chromatogram of the insect head and hemolymph showed 5 peaks while hemolymph showed 6 peaks in LD, and LLregimes. The day–night changes of melatonin increased the antioxidant enzymes (GST, CAT, POX) persisted in the insect hemolymph, but were suppressed by constant light. The present study leads us to speculate that synthesis and release of melatonin in the S.litura head occur as circadian rhythm and light has an inhibitory effect on melatonin synthesis.
Subramanian P. Subala, Eduardo E. Zubero, Moises A. Alatorre-Jimenez, and Muthugounder S. Shivakumar
Elsevier BV
Subramanian PanchuRavindraRajan Subala and Muthugounder Subramanian Shivakumar
Informa UK Limited
Abstract The present study was conducted to decipher the impact of circadian rhythm on digestive enzymes of Spodoptera litura under three photoperiods (12L:12D, 0L:24D, and 24L:0D). Longer life cycle, higher developmental traits and significant food utilizing capability were observed in dark conditions (DD), while there was no effect on survival. The activity of lactate dehydrogenase (LDH), α and β-glucosidase depended on complete absence of light (DD) while LL had a significant effect on protease activity. The presence of polypeptides (35, 60 kDa) and lower protease inhibition by PMSF in 0L:24D, and 24L:0D indicated that serine proteases (trypsin) were the main proteases in larval midgut. Overall, zymography profiles suggested that circadian variation, particularly dark period influenced the S. litura development due to fluctuations in the midgut enzymes via food utilization. Although the effect of photoperiod on digestive processes of insects is still unclear, dark regime may underlie the midgut digestive enzymes in S. litura larvae.