红豆草抗赖氨酸加苏氨酸愈伤组织变异系的选择和分析

利用红豆草不胚轴诱导的胚性愈伤组织，经过化学诱变和筛选，得到一个抗赖氨酸加苏氨酸（ＬＴ）的愈伤组织变异系，ＬＴ抗性愈伤组织在脱离选择压６个月后，仍表现出１．５倍于野生型的抗性。ＬＴ抗性可通过再生植株传递到次级愈伤组织，抗性细胞中游 离赖氨酸、苏氨酸、蛋氨酸及异氨酸都有较大提高，分别为野生型细胞的５３、５４、１．３９和４．０７倍。抗性细胞和野生型细胞中天冬氨酸激酶的总活性相近，但前者对赖氨酸的反馈抑

The Selection and Analysis of Sainfoin Callus Line Resistant to Lysine Plus Threonine

By use of tissue culture techniques, a variation callus line resistant to growth inhibition by lysine plus threonine was isolated from sainfoin calli. After growing on the absence of LT 6 months, the LT-resistant callus line kepton showing a high level of resistance which was 1. 5 times as high as that of the wildtype. LT resistance was transmitted to the secondary cultures initiated from the LT-resistant regenerants. The free pool of lysine,threonine, methionine and isoleucine increased by 1. 4-54 times in LT-resistant cells. The cativity of key enzyme in lysine biosynthesis, aspartokinase, was similar in resistent and wildtype cells , but the lysine feedback inhibition sensitivity of the enzyme from the LT-resistant cultures decreased by 50% in comparison with that of the wildtype cells in the presence of 2 mmol/L lysine.