芦笋抗S-(2-氨乙基)-L-半胱氨酸(AEC)变异体的筛选

Selection of Asparagus Variant Resistant to S-(2-amino- ethyl )-L-cysteine (AEC)

S-(2-氨乙基)-L-半胱氨酸(AEC)可抑制芦笋愈伤组织的生长,此抑制作用可被赖氨酸或甲硫氨酸部分解除。用0.5mmol/L的AEC进行筛选,得到抗性愈伤组织AR10并再生植株。AR10愈伤组织经一年多的继代培养,在离开选择剂组培继代两代后仍保持对AEC的抗性。抗性系愈伤组织还表现出对2mmol/L的半胱氨酸具交叉抗性,对1mmol/L的赖氨酸加苏氨酸表现部分交叉抗性。AR10再生植株一部分保持对AEC的抗性,而一部分则无抗性。对抗性愈伤组织及其再生植株的氨基酸分析表明,愈伤组织内游离赖氨酸、苏氨酸、甲硫氨酸都有增加,而在再生植株内却发现半胱氨酸和赖氨酸的特异性增加,分别是对照植株的5.4和4.6倍。

AEC could inhibit the growth of asparagus (Asparagus officinalis L.), this inhibition could be partially relieved by lysine or by methionine. A resistant line, AR10, was obtained after mu-tagenization and selection with 0.5 mmol/L AEC. ARID calli remained resistant after being su-bcultured on AEC-free medium for 2 generations. AR10 calli cross-resisted to 2 mmol/L cysteine and to a less extent, cross-resisted to 1 mmol/L lysine plus threonine. 2 of 5 plantlets regenerated from AR10 calli remained resistant to 0.5 mmol/L AEC, but the others were not resistant. In AR10 calli, free lysine, threonine, methionine and isoleucine slightly increased. In AEC-resistant plantlets, free lysine and cysteine specifically increased. The mechanism of resistance might be complicated.