Effect of acclimation to suboptimal temperature on chilling-induced photodamage: comparison between a domestic and a high-altitude wild Lycopersicon species

Plants of a domestic (Lycopersicon esculentum [L.] Mill. cv. Abunda) and a high-altitude wild Lycopersicon species (L. peruvianum Mill. LA 385) were g rown at near-optimal (25/20 degrees C) or suboptimal (16/14 degrees C) temp erature. Leaf discs from just fully expanded leaves were exposed to an irra diance of 1000 mu mol m(-2) s(-1) at 5 degrees C for 48 h. The effect of gr owth temperature on the susceptibility to photoinhibition of photosystem II (PSII) and its recovery, degradation of leaf pigments, chlorophyll (Chl) f luorescence quenching and xanthophyll cycle activity were examined. Leaves of L. esculentum and L. peruvianum plants grown at optimal temperature, wer e similarly susceptible to photodamage. Suboptimal-grown leaves of both spe cies showed a higher tolerance to photoinhibition than optimal-grown leaves . In both species, recovery of photoinhibited PSII was more complete in lea ves grown at suboptimal than at optimal temperature. In contrast to L. escu lentum, suboptimal-grown leaves of L. peruvianum exhibited faster kinetics of recovery from photoinhibition than optimal-grown leaves. Light-induced d egradation of leaf pigments in leaves grown at 16/14 degrees C was 2.3- and 2.7-times slower in L. esculentum and L. peruvianum, respectively, when co mpared with leaves grown at 25/20 degrees C. Non-photochemical quenching (N PQ) of Chl fluorescence developed faster in leaves of suboptimal-grown plan ts. and steady-slate levels were similar to 20% higher than in leaves of op timal-grown plants of both species. An increased pool size of xanthophyll c ycle pigments together with a slightly higher conversion state, resulted in a 1.5- (L. esculentum) or 3-fold (L. peruvianum) higher maximal zeaxanthin content in suboptimal-, as compared with optimal-grown leaves. These resul ts demonstrate that acclimation to suboptimal temperature increased the cap acity to resist chilling-induced photodamage in both the domestic and the h igh-altitude wild Lycopersicon species. However. the acclimatory response w as more pronounced in L. peruvianum than in L. esculentum, indicating a gre ater ability of the high-altitude wild species to acclimate its photosynthe tic apparatus to suboptimal temperatures. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.