宁夏枸杞体细胞胚发生过程中对金属离子的吸收速率和游离氨基酸含量的变化

Variations in Absorption Rate of Metal Ions and Content of Free Amino Acids During Somatic Embryogenesis of Lycium barbarum L.

采用多重示踪技术研究宁夏枸杞 (Lyciumbar barumL .)体细胞胚发生中对多种金属离子的吸收动态及其与游离氨基酸含量变化之间的关系。结果表明 :(1)在枸杞体细胞胚发生中对一些金属离子具有选择吸收特性 ,而且在体细胞胚发育不同时期对同一种金属离子的吸收量也不同 ;(2 )在枸杞体细胞胚发生早期对多数金属离子吸收量迅速增加 ,而后下降。到球形胚期吸收量达到第二个峰值 ,而且金属离子被吸收后提高了体细胞胚发生的频率 ;(3)枸杞体细胞胚发生中游离氨基酸总量从胚性细胞启动期开始下降 ,到胚性细胞形成期到达谷底 ,然后开始上升 ,到多细胞原胚期达到峰值 ,多数游离氨基酸含量变化与金属离子被吸收的量相交叉 ;(4 )外加RbCl和SrCl2 对枸杞体细胞胚发生具有促进作用 ,而且加大了几种游离氨基酸含量变化的幅度。

Radioactive multitracer and γ-ray measurement were used in the study, about the relation of metal ions and free amino acids on somatic embryogenesis of Lycium barbarum L.. The results show that: (1) 11 (Zr,Sr,Rb,mTc,Rh,Se,V,Mn,As,Zn and Co) of the 16 radionuclides tested were selectively absorbed during somatic embryogenesis (Fig.1). (2) The rates of absorption of different metal ions were different at the same developmental stage, the absorption rates of most metal ions were about 5%～7%/g in 10-d culture, the amount of metal ions absorbed differed at different developing stages (Fig.2). (3) The uptake quantity of some metal ions increased and then decreased after the second higher point on globular embryo along with the increase in rate of somatic embryogenesis at the early stage of somatic embryogenesis (Fig.5). (4) The amount of free amino acids reduced during the embryogenic cells were inducted to form then increased during the embryogenic cells into multi-cellular stage. The amount of some free amino acid was increased and uptake quantity of metal ion was reduced in somatic embryogenesis (Fig.4). (5) Exogenous RbCl and SrCl 2 regulate the amount of free amino acids in callus and increase the rate of somatic embryogenesis (Figs.4,5).