ORIGINAL PAPER Cadmium stress in wheat seedlings: growth, cadmium accumulation and photosynthesis Dunwei Ci • Dong Jiang • Bernd Wollenweber • Tingbo Dai • Qi Jing • Weixing Cao Received: 7 April 2009 / Revised: 7 October 2009 / Accepted: 4 November 2009 / Published online: 21 November 2009 Ó Franciszek Go ´rski Institute of Plant Physiology, Polish Academy of Sciences, Krako ´w 2009 Abstract Seedlings of wheat (Triticum aestivum L.) cultivars Jing 411, Jinmai 30 and Yangmai 10 were exposed to 0, 10, 20, 30, 40 or 50 lM of CdCl 2 in a solution culture experiment. The effects of cadmium (Cd) stress on wheat growth, leaf photon energy conversion, gas exchange, and Cd accumulation in wheat seedlings were investigated. Gas exchange was monitored at 3, 9, 24 days after treatment (DAT). Growth parameters, chlorophyll content, leaf chlorophyll fluorescence, and Cd concentra- tion in shoot and root were measured at 24 DAT. Seedling growth, gas exchange, chlorophyll content, chlorophyll fluorescence parameters were generally depressed by Cd stress, especially under the high Cd concentrations. Cd concentration and accumulation in both shoots and roots increased with increasing external Cd concentrations. Relationships between corrected parameters of growth, photosynthesis and fluorescence and corrected Cd con- centrations in shoots and roots could be explained by the regression model Y = K/(1 ? exp(a ? bX)). Jing 411 was found to be Cd tolerant considering parameters of chloro- phyll content, photosynthesis and chlorophyll fluorescence in which less Cd translocation was from roots into shoots. The high Cd concentrations were in shoots and roots in Yangmai 10 which has been found to be a relative Cd tolerant cultivar in terms of most growth parameters. Keywords Cadmium stress  Gas exchange  Chlorophyll fluorescence  Growth  Regression model  Wheat Introduction Cadmium (Cd) causes severe physiological disorders and depresses plant growth (Rai et al. 2005; Wu et al. 2007; Dell’Amico et al. 2008; Sun et al. 2008). Crop plants growing at high levels of Cd show many physiological disorders, such as reductions of chlorophyll, sugars and soluble protein, decrease in photosynthesis as well as large changes in the contents of phenols, reactive oxygen species (ROS) and related enzyme activities (Watanabe and Suzuki 2002; Maksymiec and Krupa 2006; Lin et al. 2007). Inhibited metabolic processes associated with the decline in respiration and photosynthesis ultimately lead to inhi- bition of plant growth and yield (Prasad et al. 1991; Satyakala 1997). Leaf photosynthesis is known to be highly sensitive to Cd stress (Pietrini et al. 2003; Mobin and Khan 2007; Qian et al. 2009). The decrease in CO 2 assimilation in maize seedlings is related to reduced activities of carboxylic enzymes, phosphoenol pyruvate carboxylase (PEPCase) and ribulose 1, 5-bisphosphate carboxylase (RuBPCase) (Krantev et al. 2008). Chlorophyll fluorescence is consid- ered as very useful technique to reveal the extent of Communicated by G. Klobus. D. Ci  D. Jiang  T. Dai  Q. Jing  W. Cao Key Laboratory of Crop Physiology and Ecology in Southern China, Ministry of Agriculture/Hi-Tech Key Laboratory of Information Agriculture of Jiangsu Province, Nanjing Agricultural University, 210095 Nanjing, Jiangsu Province, People’s Republic of China B. Wollenweber Department of Genetics and Biotechnology, Research Centre Flakkebjerg, Aarhus University, 4200 Slagelse, Denmark D. Jiang (&) College of Agriculture, Nanjing Agricultural University, No. 1 Weigang Road, 210095 Nanjing, Jiangsu Province, People’s Republic of China e-mail: jiangd@njau.edu.cn 123 Acta Physiol Plant (2010) 32:365–373 DOI 10.1007/s11738-009-0414-0