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The response of five Lycopersicon species to 14 days moderate chilling at 10°C under low light (75 μmol m−2 s−1) and subsequent recovery was examined by measurements on relative shoot growth rate, leaf dry matter and carbohydrate content, CO2‐exchange and pigment composition. In addition, the susceptibility to dark chilling and temperature dependence of chloroplast electron transport were analyzed by Chl a fluorescence measurements. During 7 days of recovery at 25/20°C subsequent to chilling, the domestic tomato Lycopersiconesculentum (L.) Mill. cv. Abunda exhibited a small capacity for shoot regrowth (39%) compared to the low‐altitude wild species L. pimpinellifolium (Jusl.) Mill. PI187002 (82%) and three wild species originating from high altitude: L. peruvianum Mill. LA 385 (92%), L. hirsutum Humb. & Bonpl. LA 1777 (67%) and L. chilense Dunn. LA 1970 (71%). The inter‐specific differences in chilling sensitivity at the chloroplast level, analyzed by the decline of the maximum rate of induced Chl fluorescence rise (FR) after 40 h at 0°C and the temperature at which qP reached the value 0.5, correlated in general well with the measured differences at whole plant level, measured by the post‐chilling regrowth capacity. Chilling resulted in a larger increase in leaf dry matter content in L. esculentum (45%) and L. pimpinellifolium (37%) compared to the high‐altitude species (13–16%), which could be attributed to a stronger accumulation of both soluble sugars and starch in mature leaves of the domestic and low‐altitude species. Photosynthetic and dark respiration rates during chilling could not account for this difference. The recovery of photosynthesis was better in the high‐altitude species. Chl content per unit leaf area decreased more throughout the experiment in the domestic and low‐altitude species (63–73%) than in their relatives from high altitude (8–29%). In response to chilling, the domestic and low‐altitude species showed an increase in the total xanthophyll cycle pool on Chl basis, whereas the de‐epoxidation state of the xanthophyll cycle increased in the high‐altitude wild species. Both responses resulted in increased zeaxanthin levels in chilled leaves of all Lycopersicon species.

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Most chloroplasts undergo changes in composition, function and structure in response to growth irradiance. However, Tradescantia albiflora, a facultative shade plant, is unable to modulate its light-harvesting components and has the same Chl a/Chl b ratios and number of functional PS II and PS I reaction centres on a Chl basis at all growth irradiances. With increasing growth irradiance, Tradescantia leaves have the same relative amount of chlorophyll-proteins of PS II and PS I, but increased xanthophyll cycle components and more zeaxanthin formation under high light. Despite high-light leaves having enhanced xanthophyll cycle content, all Tradescantia leaves acclimated to varying growth irradiances have similar non-photochemical quenching. These data strongly suggest that not all of the zeaxanthin formed under high light is necessarily non-covalently bound to major and minor light-harvesting proteins of both photosystems, but free zeaxanthin may be associated with LHC II and LHC I or located in the lipid bilayer. Under the unusual circumstances in light-acclimated Tradescantia where the numbers of functional PS II and PS I reaction centres and their antenna size are unaltered during growth under different irradiances, the extents of PS II photoinactivation by high irradiances are comparable. This is due to the extent of PS II photoinactivation being a light dosage effect that depends on the input (photon exposure, antenna size) and output (photosynthetic capacity, non-radiative dissipation) parameters, which in Tradescantia are not greatly varied by changes in growth irradiance.