Morpho-physiological and biochemical responses of different sunflower inbred lines (Helianthus annuus L.) subject to water stress

FEDERICO RAMÍREZ; SERGIO ALEMANO; ALDANA BOERO; ANDREA ANDRADE; ANA VIGLIOCCO

Congreso; XXXIII Argentinian Meeting of Plant Physiology; 2021

In sunflower plants, water stress modifies various processes involved in their growth and development. Our aim was to evaluate the morpho-physiological and biochemical responses of seedlings of four sunflower inbred lines (B59, B71, C803 and R461-4) exposed to water stress during the early vegetative growth (V2). Seedlings were grown in pots with sand inside Conviron PR48 Environmental Rooms. At 4th day after sowing, and subsequently each 3 days, irrigations were carried out at field capacity with Hoagland solution 50% ionic strength (control) and 400 mM mannitol solution (water stress). When the seedlings reached the V2 growth stage, they were harvested, sectioned in aerial and radical part and the different parameters were evaluated. All the morpho-physiological and biochemical parameters analyzed were altered by water stress. The leaf area showed a significant decrease in all lines. Stomatal conductance and osmotic potential decreased significantly in B59 and B71 lines. Regarding the hormonal content, ABA and SA increased in aerial part of seedlings of the four inbred lines in response to water stress. In radical part of B59 and C803 water stressed-seedlings ABA was the most abundant phytohormone whereas in B71 and R461-4 its content decreased. JA increased in C803 water stressed-seedlings. The total carbohydrates content significantly increased in C803 and R461-4 lines under water stress. The obtained results demonstrated that the inbred lines showed different adaptation strategies as a consequence of imposed water stress. Furthermore, this response was closely related to the sensitivity of each line to stress.