Cadmium toxicity affects photosynthesis and plant growth at different levels

• DOI: 10.1007/s11738-012-1167-8
• Publication Date: 2012-12-05T21:18:48Z
• Authors: Maria Celeste Dias; Cristina Monteiro; José Moutinho-Per...; Carlos Correia; Berta Gonçalves; Conceição Santos
• Keywords: Plant Physiology; Photosynthetic efficiency; Phytotoxicity; Assimilation (phonology)

In this article we discuss and update some of the effects of Cd toxicity on the photosynthetic apparatus in a model crop Lactuca sativa. Seeds of L. sativa were germinated in solutions with 0, 1, 10 and 50 μM of Cd(NO3)2 and then transferred to a hydroponic culture medium. After 28 days, the effects of Cd on the photosynthetic apparatus of lettuce were analysed. Exposure of lettuce to 1 μM Cd(NO3)2 affected already plant growth (dry biomass), but, did not induce serious damages in the photosynthetic apparatus. However, increasing concentrations of this metal to 10 and 50 μM promoted a strong reduction of the maximum photochemical efficiency of PSII and an impairment of net CO2 assimilation rate, putatively due to Rubisco activity decrease. This ultimately results in a strong inhibition of plant growth. Nutrient uptake and carbohydrate assimilation were also severely affected by Cd.