Impact of high temperature on the accumulation of proline in genetically divergent cereal varieties

Growth and development of cereals is affected by abiotic factors, particularly by high temperature. An important factor in plant adaptation to abiotic stress can be the proline accumulation. Proline is an amino acid involved in a series of metabolic processes and is important as a protein stabilizer, osmolite and antioxidant. Under normal physiological conditions, the proline makes up less than 5% of the free amino acids in the plant, while due to stress this amount can increase to over 80%. Field experiment was conducted with the aim to determine the effect of high temperature on the proline content in different cereal varieties during two vegetative seasons. For the investigation, plant material of 8 genetically divergent winter wheat varieties, 1 variety of triticale and 1 oat variety were used. Samples were collected in days with moderate midday air temperatures of 24-26 °C in the milk stage and after a few days in the same phenological stage, in conditions of high midday air temperatures of 34-36 °C.