Effects of mechanical wounding, current application and heat treatment on chlorophyll fluorescence and pigment composition in tomato plants

Chlorophyll fluorescence quenching parameters and pigment content of wild-t ype tomato plants (Lycopersicon esculentum Mill. cv. Moneymaker) mere analy zed upon mechanical mounding, current application and heat treatment. Upon all stimuli the non-photochemical quenching increased significantly in loca l and systemic tissue. Vice versa, the photochemical quenching decreased. T otal chlorophyll content remained almost constant, zeaxanthin content incre ased 5-6-fold, antheraxanthin content rose also, violaxanthin and neoxanthi n on the other hand decreased significantly. These data indicate a similari ty of processes on the level of photosynthesis and pigment composition that are induced by light-stress and those induced by mechanical mounding, curr ent application and heat treatment, which all lead to an inhibition of phot osynthesis.