A. R. Abbasi - Department of Agronomy and Plant Breeding, Faculty of Agricultural Science and Engineering, University College of Agriculture and Natural Resources, University of Tehran, Karaj, Islamic Republic of Iran.
B. Mohammadi - Department of Agronomy and Plant Breeding, Faculty of Agricultural Science and Engineering, University College of Agriculture and Natural Resources, University of Tehran, Karaj, Islamic Republic of Iran.
R. Sarvestani - Department of Agronomy and Plant Breeding, Faculty of Agricultural Science and Engineering, University College of Agriculture and Natural Resources, University of Tehran, Karaj, Islamic Republic of Iran.
F. Mirataei - Department of Agronomy and Plant Breeding, Faculty of Agricultural Science and Engineering, University College of Agriculture and Natural Resources, University of Tehran, Karaj, Islamic Republic of Iran.

Vicia sativa L., an annual winter growing leguminous plant, is a valuable source of protein and minerals for cattle. Drought is one of the key stress factors that influence plant growth and development. In order to investigate common vetch physiological and molecular responses under Normal irrigation (N) and two levels of drought stress [S۱= ۳۰% and S۲= ۱۰% Field Capacity (FC)], a greenhouse experiment was carried out on two genotypes, namely, Mahalimaraghe and ۴۱,and some physiological traits [e.g. Relative Water Content (RWC), Electro Leakage (EL), total protein, chlorophyll (a, b), and carotenoid content] were measured and expression patterns of three genes (sod, aq۱ and bzip) were evaluated by real-time quantitative RT-PCR analysis. Results showed that expression pattern of all three genes and physiological responses had significantly changed in response to the stress. The highest increase in the expression of each of the three genes was observed in Mahalimaraghegenotype in S۱ condition compared to N. In contrast, under S۲ condition compared to N, the highest increase in expression of the three genes was observed in genotype ۴۱. In comparison of S۲ with S۱, the highest changes in expression of all the three genes was observed in Mahalimaraghe genotype. All together, the obtained results may facilitate the understanding of molecular mechanism of V. sativa in response to drought stress, and also provide the basis of effective genetic engineering strategies for improving stress tolerance of V. sativa.

Dought tolerance, Expression pattern, Gene expression, Molecular response, Osmotic adjustment