High temperature, drought and their interaction induced protein alterations in sensitive and tolerant wheat varieties

Two contrasting wheat (Triticum aestivum L.) cultivars WH730 (high temperature tolerant) and UP2565 (high temperature sensitive) were tested for differential response to combined and individually applied high temperature (HT) and drought (D) stress at seedling stage for peptide profile. Initial profile of the stress induced peptides was outlined via SDS electrophoresis of leaf extracts. Electrophoretic pattern of proteins revealed expression of new bands as well as disappearance of certain others in HT, D and interactive HT+D stress treated and revived samples in both wheat varieties relative to untreated control samples. Some of the bands that appeared in stress treated seedlings were also present after revival indicating their protective role, while some new peptides synthesized after stress but disappeared after revival period may be designated true stress proteins. However, all the plants from heat, drought and their interactive stress treatments continued to grow during recovery period. This suggests that these proteins and other newly synthesized proteins may have protective effects at high temperature (40°C) and water scarcity and provide plants for healthy growth during the recovery period. Furthermore, elucidating the functions of proteins expressed by genes in stress tolerant and susceptible plants may provide important information for designing new strategies for crop improvement.