Effect of short-term heat stress on total sugars, proline and some antioxidant enzymes in moth bean (Vigna aconitifolia)

Heat stress leads to an array of physiological, biochemical, and molecular changes in plants affecting its growth and development. An experiment was conducted to find out the effect of short-term heat stress on osmo-protectant and antioxidants in 37 genotypes (32 mutants and five varieties) of moth bean (Vigna aconitifolia). Seeds were grown in plastic pots containing sterilized vermiculite. Heat stress conditions were created by exposing seven days old seedlings at 42 °C for one hour in hot air oven. Analysis of various parameters was carried out at three days after heat stress. A significant over-accumulation of total sugar and proline along with an increased activity of CAT, GPOX and SOD was observed in most of the genotypes under heat stress. However, correlation analysis among heat stress induced biochemical parameters suggests that none of these traits were associated with the level of thermo-tolerance except GPOX activity. Among 37 genotypes, on the basis of number of fresh plants with least wilting symptoms, six were categorized as tolerant, 13 as moderately tolerant and 18 as susceptible accession. Eventually, it is evident that thermo tolerance and biochemical parameters can be efficiently altered and improved through mutagenesis, though this altered tolerance level could not be associated with the parameters studied in the present investigation.