D-丙氨酸对大白菜种子萌发的影响

Effect of D-alanine on the Germination of Chinese Cabbage

D-氨基酸氧化酶基因是一种新型的具有生态安全性的选择基因,以D-丙氨酸作为筛选剂,在国外已有成功的报道,而在国内还未见相关信息。试验以大白菜[Brassica campestris L.ssp.pekinensis(Lour.)Olsson]为材料,研究了D-丙氨酸对大白菜种子萌发的影响。结果表明,随着D-丙氨酸浓度的升高,对大白菜种子萌发生长的抑制也增大,受抑制最严重的器官是根系,其次是下胚轴,最后是子叶。高浓度的D-丙氨酸溶液导致种子不能萌发,当D-丙氨酸浓度为27.5 mmol/L时,大白菜种子的发芽率在5%以下;当D-丙氨酸浓度为30.0 mmol/L时,大白菜种子的发芽率为0,故27.5～30.0 mmol/L的D-丙氨酸可以作为适宜的筛选浓度。同时测定了萌发的大白菜幼苗可溶性糖和可溶性蛋白含量的变化,低浓度的D-丙氨酸可以刺激二者的升高,过高则导致降低,但不同品种之间表现有差异。

The D-amino acid oxidase gene was a new selectable gene which was safe in the ecology,and was it was used in abroad,when D-alanine was used as the selective agent.The presented test was carried out with Chinese cabbage[Brassica campestris L.ssp.pekinensis（Lour.） Olsson]used as the material,to study the affection of D-alanine on germination of Chinese cabbage.The results showed that the germination and growth were inhibited along with the increasing of the concentration of D-alanine.The most damaged organ was root,the hypocotyl was second,and the cotyledon was the last.The D-alanine at high concentration completely inhibited the germination of the seeds of Chinese cabbage.The germination rate of Chinese cabbage was under 5% when treated by 27.5 mmol/L D-alanine;and it was 0 when treated by 30.0 mmol/L D-alanine.So 27.5~30.0 mmol/L was the available selective concentration of D-alanine.The content of soluble sugar and soluble protein of the seedlings were measured.Low concentration of D-alanine both increase of solubled sugar and soluble protein.High concentration of D-alanine might led to the decrease of them,but there were different pattern among different breeds.