Agricultural Sciences in China 2009, 8(4): 410-417 April 2009 © 2009, CAAS. All rights reserved. Published by Elsevier Ltd. The Relationship Between Developmental Accumulation of Leaf Soluble Proteins and Vernalization Response of Wheat (Triticum aestivum L.em. Thell) M Majdi 1 , G Karimzadeh 1 and S Mahfoozi 2 1 Plant Breeding and Biotechnology Department, Faculty of Agriculture, Tarbiat Modares University, P.O. Box 14115-336, Tehran 1497713111, Iran 2 Physiology-Agronomy Unit of Department of Cereals Research, Seed and Plant Improvement Institute, Karaj 315854119, Iran Abstract The relationship between vernalization requirement and quantitative and qualitative changes in total leaf soluble proteins were determined in one spring (cv. Kohdasht) and two winter ( cvs. Sardari and Norstar) cultivars of wheat ( Triticum aestivum L.) exposed to 4°C. Plants were sampled on days 2, 14, 21 and 35 of exposure to 4°C. The final leaf number (FLN) was determined throughout the vernalization periods (0, 7, 14, 24, and 35 d) at 4°C. The final leaf number decreased until days 24 and 35 in Sardari and Norstar cultivars, respectively, indicating the vernalization saturation at these times. No clear changes were detected in the final leaf number of Kohdash cultivar, verifying no vernalization requirement for this spring wheat cultivar. Comparing with control, clear cold-induced 2-fold increases in proteins quantity occurred after 48 h following the 4°C-treatment in the leaves of the both winter wheat cultivars but, such response was not detected in the spring cultivar. However, the electrophoretic protein patterns showed between-cultivar and between-temperature treatment differences. With increasing exposure time to 4°C, the winter cultivars tended to produce more HMW polypeptides than the spring cultivar. Similar proteins were induced in both Sardari and Norstar winter wheat cultivars, however, the long vernalization requirement in Norstar resulted in high level and longer duration of expression of cold-induced proteins compared to Sardari with a short vernalization requirement. These observations indicate that vernalization response regulates the expression of low temperature (LT) tolerance proteins and determines the duration of expression of LT- induced proteins. Key words: soluble proteins, wheat, Triticum aestivum L., final leaf number, vernalization, cold Received 14 July, 2008 Accepted 15 September, 2008 Correspondence G Karimzadeh, E-mail: karim_gh@modares.ac.ir INTRODUCTION Vernalization is defined as the acceleration of the abil- ity to flower by a chilling treatment (Chauvin et al . 1993). On low temperature (LT) exposure, vernal- ization-requiring plants continue to reduce their final leaf number (FLN) up to the point of vernalization saturation (Fowler et al . 1996a; Mahfoozi et al . 2001a). Vernalization requirement is critical to win- ter plants as it prevent transition to the reproductive phase in regions with cold winters. Fulfillment of vernalization requirement has been suggested for the loss of LT tolerance of over wintering cereals (Fowler et al. 1996a, b; Trevaskis et al . 2007; Herndl et al . 2008).