Investigation of protein profile of nano-silver preserved mulberry leaves and silkworm larvae fed with the same leaves.

The present study deals with a current arising problem of landless farmers and a challenge in solving an age-long difficulty of silk farmers: feeding of larvae during rainy season. On feeding wet mulberry leaves, the mortality rate of larvae increases, as a result of which productivity decreases. Biogenic synthesized silver nanoparticles were found to be effective in preserving mulberry leaves at the post-harvest stage. A major threat during preservation is the decline in the protein content of leaves, putting a negative impact over productivity, as leaf protein content is a major contributor towards silk gland development. Another threat resides with the generation of excessive reactive oxygen species (ROS), causing cellular damage and thereby enhancing senescence. SDS (sodium dodecyl sulphate) gel analysis of mulberry leaf protein reflects the preservative potential of nanosilver solution. Leaves preserved in nanosilver solution showed gel banding pattern almost constant till the entire duration of preservation, i.e. for 7 days, and the banding pattern was more prominent and invariable than the banding pattern showed by leaf protein preserved in silver nitrate and distilled water. SDS banding pattern of silkworm larvae fed with nanosilver-preserved leaves appeared almost similar to that of larvae fed with fresh leaves, which also reflects a high preservative potential of nanosilver solution. Through isozyme profiling, superoxide dismutase (SOD) and catalase (CAT) activity was found to be active in both nanosilver-preserved mulberry leaves and silk gland of larvae fed with the same preserved leaves;also, this up-regulated peroxidase activity was observed in preserved leaves. Isozyme profiling reflects the presence of sufficient defensive activity to protect against damage caused by ROS accumulation. OHR-LCMS profiled proteins through string analysis detected involvement of photosynthesis-associated proteins and stress-inhibiting proteins, helping to prevent senescence and thus enhancing shelf life. [ABSTRACT FROM AUTHOR]