Improving tolerance against drought in canola by penconazole and calcium.

Drought stress is one of the most important environmental factors that limit plant growth. Canola is an important agricultural crop grown primarily for its edible oil. In this study, penconazole (PEN), a triazole growth regulator, and calcium (Ca2+), a secondary messenger, were used to analyses their role in decease sensitivity and induce tolerance to drought stress in canola. Plants were treated by various PEG concentrations (0, 5, 10, and 15%) without or with PEN (15 mg l-1) and Ca2+ (15 mM). According to the obtained results in two cultivars of canola (RGS003 and Sarigol), improvement of growth by PEN and Ca2+observed at low concentration of drought (5%). Betterment of growth by PEN can be explained by induction in DPPH (1, 1-diphenyl-2- picrylhydrazyl), chlorophyll and P content and reduction in Electrolyte leakage in cultivar RGS003. Growth recovery by PEN is concomitant by increase in DPPH, succinate dehydrogenase, chlorophyll, carotenoid and K+ content in cultivar Sarigol. Ca2+ treatment by induction in Relative water content, DPPH, chlorophyll, carotenoid, indole-3-acetic acid content and the content of Ca2+ and K+ causes increase in growth in cultivar Sarigol. Overall, application of PEN and Ca2+ improved the performance in canola under drought stress. These results provide novel insights about the physiological and molecular roles of PEN and Ca2+ in canola plant tolerance against drought stress.