Studies on enzymes Superoxide dismutase and Catalase in midgut of Samia ricini under thermal stress condition

In the present study, 5^th instar larvae on Samia ricini were subjected into temperature stress (31.2 ± 1°C) every day for 5 hrs till mature stage to assess the enzymes superoxide dismutase (SOD) and catalase (CAT) in midgut tissue of different eco-races of eri silkworm viz., Borduar, Titabar and Mendipathar. Over generation of reactive oxygen species (ROS) can cause midgut cellular damage as a result it might affect the growth and production of eri silkworm. The temperature stress resulted significant increase in the enzyme SOD and CAT which indicated a defence mechanism to protect cellular damage against ROS. The results also showed that ROS level increased significantly under temperature stressed condition, compared with control. The study confirmed that thermal stress can be responsible for cellular damage and to overcome such stress, SOD and CAT play a key role in protecting oxidative damage in midgut tissue of eri silkworm.