Effect of Temperature, Light, Nutrients and Dehardening on Abscisic Acid Induced Cold Hardiness in Bromus inermis Leyss Suspension Cultured Cells

摘要: The effects of culture conditions on abscisic acid (ABA)-induced freezing tolerance were determined in smooth bromegrass (Bromus inermis Leyss cv. Manchar) cell suspension cultures. Bromegrass cultures initiated with 2g fr wt cells achieved maximum tolerances (greater than —32°C) at 25 to 30°C the presence 75 100^M ABA. High levels induced by ABA correlated high growth rates and 30°C. In control cells, incubation 10°C optimum hardiness minimal growth. Prolonged exposure (6 weeks) 3°C, or without ABA, increased only several degrees. Exogenous concentrations greater IOO^M not inhibitory Repeated however, retarded made tolerant temperatures below — 40°C. Removal from medium resulted dehardening both 3°C. Nitrogen had a marginal effect ABA-induced hardening 25°C, but inhibited age-dependent Light no cultured cells. Addition 10% sucrose, 30 min prior freezing, treated for 4 days more 15°C. These observations are discussed relation contrasting behaviour low temperature photoperiod dependent cold acclimation plants.