日本桃叶珊瑚的冷驯化及抗寒机制研究  

Study on cold acclimation and freezing-tolerance mechanism of Aucuba japonica cv. Variegata

作　　者：高述民[1] 程朋军[1] 郭惠红[1] 郭蔚兰[1] 李凤兰[1] 沈应柏[1] 

机构地区：[1]北京林业大学生物科学与技术学院,北京100083

出　　处：《西北植物学报》2003年第12期2113-2119,共7页Acta Botanica Boreali-Occidentalia Sinica

基　　金：国家林业局 "948" 引进项目(99-4-7) ;北京林业大学研究生培养基金资助.

摘　　要：冷驯化能大大提高植物的抗寒性.研究测定了引进日本桃叶珊瑚 AucubajaponicaThunb.cv.Variegata 苗木在不同越冬条件下的抗寒性指标及在低温锻炼前后的半致死温度,并通过双向电泳分离与抗寒性有关的特异蛋白.结果表明,日本桃叶珊瑚能安全地越冬 最低气温为-18℃ ,日本桃叶珊瑚叶片抗冻的细胞结构特征在于其叶肉细胞排列疏松,间隙大,有利于防止细胞内结冰;经过4℃冷驯化的植株低温半致死温度为-21℃,而未经冷驯化的植株低温半致死温度为-7.5℃;双向电泳分析发现至少有3个常温下存在而低温下消失的蛋白多肽,分子量分别为A15kD、B14kD、C56kD、D26kD.依据分子量和等电点初步分析,A与组蛋白H2A相似,B与组蛋白H2B相似;另B与Rubisco小亚基分子量相近,C与Rubisco大亚基分子量相近,前一种情况可能与有关抗寒基因的表达有关,后一种情况可能与低温下的光合作用减弱有关.Freezing tolerance of plant could be enhanced by cold acclimation. Some freezing tolerance mechanisms were investigated with imported plant—Aucuba japonica Thunb. cv. Variegata , such as the cold resistance index under different culturing ways in winter and the changes of plant half lethal temperature before or after cold acclimation. Some special protein peptides that may be correlated with antifreeze were isolated by 2-dimensional electrophoresis. The results showed that field plants(Aucuba japonica var.Variegata) could exist safely in winter without any covers (the lowest temperature was -18℃), the reason for leaves antifreeze might be that its mesophyll cells arranged loosely and that they were good at avoiding intracellular ice accumulation.The half lethal temperature was -21℃ when the plant were treated under cold acclimation (cultured at 4℃ for two months), but the half lethal temperature was only -7.5℃ when the plant were cultured under normal temperature.There were at least 3 special proteins of leaves found when cultured under normal temperature, but they disappeared under low temperature, and the molecular weight of A is about 15 kD, B 14 kD, C 56 kD and D 26 kD.respectively. According to MW and PI, A is similar to histone chromosomal protein H2A, B is similar to histone chromosomal protein H2B, they regulate the expression of antifreeze interrelation genes.Another viewpoint is that B is similar to a small subunit of Rubisco, C is similar to a large subunit of Rubisco by MW, it is correlated with the regulation of photosynthetic rate.

关 键 词：日本桃叶珊瑚 冷驯化 抗寒性 抗寒机制 冻害 

分 类 号：Q945.78[生物学—植物学]