Cadmium (Cd) toxicity is a serious limitation for agricultural production. In this study, we explored tolerance mechanism associated with Cd toxicity tolerance in alfalfa plants. We used three distinct alfalfa cultivars M. sativa cv. Vernal, M. sativa cv. Zhung Mu, and M. sativa cv. Xing Jiang Daye in this study. Cd showed declined chlorophyll score in Xing Jiang Daye compared with Zhung Mu and Vernal. No significant change observed among the cultivars for root and shoot length. Atomic absorption spectroscopy analysis demonstrated a significant accumulation of Cd, Fe, S and PC in distinct alfalfa cultivars. However, Zhung Mu and Xing Jiang Daye declined Cd accumulation in root, where Fe, S and PC incremented only in Zhung Mu. It suggests that excess Cd in Zhung Mu possibly inhibited in root by the increased accumulation of Fe, S and PC. This was further confirmed by the response of Fe (MsIRT1) and S transporters (MsSULTR1;2 and MsSULTR1;3), and MsPCS1 genes associated with Fe, S and PC availability and translocation in roots and shoots. It suggests that specially the transcript signal inducing the responses to adjust Cd especially in Zhung Mu. This finding provides the essential background for further molecular breeding program for forage crops.

ABSTRACT
Ⅰ. INTRODUCTION
Ⅱ. MATERIALS AND METHODS
    1. Plant growth and Cd treatment
    2. Plant growth and photosynthesis parameters
    3. Elemental concentration in root and shoot
    4. Determinatin of phyochelatins (PCs)
    5. Gene expression analysis
    6. Statistical analysis
Ⅲ. RESULTS AND DISCUSSION
Ⅳ. CONCLUSION
Ⅴ. ACKNOWLEDGEMENTS
Ⅵ. REFEENCES

• Ki-Won Lee(Grassland and Forage Division, National Institute of Animal Science, Rural Development Administration)
• Sang-Hoon Lee(Animal Genetic Resources Research Center, National Institute of Animal Science, RDA)
• Yowook Song(Grassland and Forage Division, National Institute of Animal Science, Rural Development Administration)
• Hee Jung Ji(Grassland and Forage Division, National Institute of Animal Science, Rural Development Administration)
• Bo Ram Choi(Grassland and Forage Division, National Institute of Animal Science, Rural Development Administration)
• Eun A Lim(Grassland and Forage Division, National Institute of Animal Science, Rural Development Administration)
• Md Atikur Rahman(Grassland and Forage Division, National Institute of Animal Science, Rural Development Administration) Corresponding author