Intracellular Ca2+ Changes During Cold Stress in CBF1-overexpress Arabidopsis
低温胁迫下拟南芥CBF1超表达突变体胞质中Ca2+浓度的变化

Plant growth is greatly affected by low temperature. Cold shock elicits an immediate increase in free Ca2+ concentration in plant cells. Here, we focused on the expression of CBF1 under low temperature treatment and the cold-triggered Ca2+ responses in CBF1-overexpressing Arabidopsis. CBF1 was induced by low temperature. To address the relation between CBF1 and Ca2+, we measured cold-triggered Ca2+ responses in CBF1-overexpressing Arabidopsis. CBF1-overexpressing plants exhibited a higher mean peak Ca2+ concentration than did wild-type plants, but the Ca2+ signature adjacent to the vacuolar membrane increased to similar levels in both plants. In Arabidopsis seedlings pretreated with EGTA or LaCl3, the cold shock-induced increase of Ca2+ concentration was inhibited. The cytoplasmic Ca2+ concentration in CBF1-overexpressing and wild-type plants decreased to the same level. Thus, the results suggest that Ca2+ is involved in the process of the CBF1 response to low-temperature signal transduction, and the CBF1-overexpress may enhance freezing tolerance of plants by increasing the cytoplasmic free Ca2+ concentration.