Acidic soil significantly reduces crop productivity mainly due to aluminum (Al) toxicity. Alfalfa (Medicago sativa L.) roots were exposed to aluminum stress (Al3 +) in calcium chloride (CaCl2) solution (pH4.5) and root growth, physiological and antioxidant enzyme responses were investigated. The root growth (length) was significantly inhibited after 48 h of aluminum stress imposition. Histochemical staining with hematoxylin indicated significant accumulation of aluminum in Al stress-treated root tissues. Histochemical assay were also performed to detect superoxide anion, hydrogen peroxide and lipid peroxidation, which were found to be more in root tissues treated with higher aluminum concentrations. The enzymatic activity of CAT, POD and GR in root tissues was slightly increased after Al stress treatment. The result suggests that Al stress alters root growth in alfalfa and induces reactive oxygen species (ROS) production, and demonstrates that antioxidant enzymes involved in detoxification of Al-mediated oxidative stress.

ABSTRACT
Ⅰ. 서 론
Ⅱ. 재료 및 방법
    1. 식물재료 및 스트레스 처리
    2. 뿌리생장 측정
    3. 알루미늄 축적의 histochemical 분석
    4. H2O2와 O2- 의 histochemical 측정
    5. Lipid peroxidation 측정
    6. 뿌리 단백질 분리 및 항산화효소 활성 측정
    7. 통계 처리
Ⅲ. 결과 및 고찰
    1. 알루미늄 스트레스에 따른 뿌리생장 저해
    2. 뿌리 조직에서 Al 스트레스 처리에 따른 Al의 축적 비교
    3. ROS 축적 및 lipid peroxidation
    4. 항산화 효소 활성 비교
Ⅳ. 결 론
Ⅴ. Acknowledgements
Ⅵ. REFERENCES

• 민창우(경상대학교 응용생명과학부 (BK21 Plus)/농업생명과학연구원) | Chang-Woo Min (Division of Applied Life Sciences (BK21 Plus), IALS, Gyeongsang National University)
• 칸인앰(경상대학교 응용생명과학부 (BK21 Plus)/농업생명과학연구원) | Inam Khan (Division of Applied Life Sciences (BK21 Plus), IALS, Gyeongsang National University)
• 이병현(경상대학교 응용생명과학부 (BK21 Plus)/농업생명과학연구원) | Byung-Hyun Lee (Division of Applied Life Sciences (BK21 Plus), IALS, Gyeongsang National University) Corresponding author