药蒲公英(Taraxacum officinale Weber)耐1．5％NaCl变异体的筛选及特性分析  

Selection and Identification of Salt-tolerant Variants of Taraxacum officinale

作　　者：张新果[1] 李银心[1] 陈华[2] 石武良[1] 

机构地区：[1]中国科学院植物研究所光合作用与环境分子生理学重点实验室 [2]中国科学院遗传与发育研究所,北京100101

出　　处：《生物工程学报》2008年第2期262-271,共10页Chinese Journal of Biotechnology

基　　金：国家863计划课题(No．2007AA091705);~~中国科学院重要方向性项目(No．KSCX2-YW-N-003)资助~~

摘　　要：为提高药蒲公英的耐盐性,用20～30 d大小的药蒲公英叶片诱导愈伤,获得的愈伤以NaCl作为选择因子,用直接筛选的方法,每3周进行一次继代培养,经3个月继代筛选获得了耐1.5%NaCl的药蒲公英愈伤组织,将耐1.5%NaCl的药蒲公英愈伤组织接种在分化培养基上分化出芽,之后将再生芽转接到生根培养基中进行生根培养,经4个月得到了12株耐1.5%NaCl的药蒲公英再生植株。与野生型相比,耐盐植株叶片宽大、叶柄粗短、叶表面覆盖白色细毛,根粗壮较短,花茎中部具2 cm左右的苞叶。RAPD(Random amplified polymorphic DNA,随机扩增的多态性DNA)和SDS-PAGE检测表明,耐盐植株与对照植株在DNA及蛋白水平上均存在明显差异。1.5%NaCl处理后,与普通再生植株相比,耐盐株系的抗氧化酶活性明显提高,脯氨酸含量上升幅度更为显著,而丙二醛(MDA)含量降低,其主要药用成分黄酮的含量显著增加。这些结果说明耐盐植株的抗氧化防御能力明显增强。以上结果表明耐1.5%NaCl的药蒲公英再生植株为耐1.5%NaCl药蒲公英变异体,这些耐盐变异体有望成为抗盐耐海水蔬菜家族的新成员。同时,这些耐盐变异体植株比普通植株具有更高的医用商业价值。耐1.5%NaCl的药蒲公英再生变异体遗传稳定性的研究正在进行中。In order to obtain salt-tolerant variant plants of Dandelion （Taraxacum officinale Weber）, the leaf discs were excised from 20 to 30-day old seedlings to produce callus, then the induced calli were transferred to selection mediums containing 1.5% NaCl. After regenerating and rooting, these salt-tolerant calli ffmaUy developed into 12 variant plantlets. Compared with the wild-type, these regenerated plants produced more trichomes on their leaves, and had larger leaves and shorter petioles. Additionally, the dumpy roots and an approximately 2-cm bract in middle parts of the floricanes were clearly observed in these salt-tolerant plants. By RAPD（ Random Amplified Polymorphic DNA） and SDS-PAGE analysis, these salt-tolerant plants showed differences from the control at DNA and protein levels. With 1.5% NaCl treatment, the antioxidant enzyme activity, proline content, and flavonoid concentration were higher in these salt-tolerant plants, whereas maloaldehyde concentration was significantly lower. Salt-tolerant lines of T. officinale showed stronger anti-oxidative activity and higher flavonoid contents.

关 键 词：活性氧清除剂 耐盐变异体 药蒲公英 叶片外植体 

分 类 号：S567.239[农业科学—中草药栽培] Q943.2[农业科学—作物学]