Plant hormone signaling is intricately involved with ubiquitin proteasome system. In plants, protein degradation mediated by ubiquitin 26S proteasome system (UPS) regulates every cellular process, including abiotic - biotic stresses to ensure environmental adaptation and developmental plasticity. The grain-filling stage is critical to the yield and quality of wheat and is very sensitive to high temperatures. High-temperature fluctuations decrease grain plumpness, starch content, protein accumulation, impacting yield and quality. Thus terminal heat stress is one of the top most research priorities in wheat crop today. To explore involvement of various plant hormones at individual level and the UPS in modulation of heat stress response and tolerance this study was initiated. A popular commercial cultivar of Indian bread wheat HD2967 seeds were primed with a range of eight different plant hormones in various concentration with and without exposing to high temperature stress at 42°C for two hours and raised in pots in the net house during the crop season. At the anthesis stage plants were exposed to high temperature in situ in field intermittently for three days using a heat trap chamber which maintained a temperature 3 to 4°C above the ambient. Various tissue samples were collected for RNA isolation and comprehensive phenotyping carried out in the treated and control plants for two crop seasons. We recorded similar as well as conflicting response for each hormone treatment at physiological, biochemical, morphological and molecular level. Transcript expression profiling of Skp1, an essential component of ubiquitin proteasome system showed differential activity under ambient and heat stress condition. Memory of a past event may shape or ‘prime’ the response to future stimuli, resulting in stimulus-dependent and phenotypic plasticity of response traits allowing an individual to adjust its phenotype to its environmental experience , heat stress in this case. Our results showed divergent as well as synergistic effect of various hormones in wheat plants after priming and subsequent exposure to higher temperature during grain development stage in field condition for two crop seasons. Differential and positive induction of the UPS component confirms their involvement and reveals avenue for breeding for heat tolerant wheat crop.