Kleinhofs A, Haskins F A, Gorz H J
Department of Agronomy, University of Nebraska, Lincoln, Nebraska.
Plant Physiol. 1966 Oct;41(8):1276-9. doi: 10.1104/pp.41.8.1276.
Phenylalanine ammonia-lyase activity was investigated in preparations representing various parts of sweetclover (Melilotus alba Desr.) plants of CuCu and cucu genotypes. In contrast to other plant parts, very young leaves and stems of CuCu plants displayed high phenylalanine ammonia-lyase activity. Initial leaf samples from CuCu plants were approximately 3 times as high in enzyme activity as leaves from cucu plants, but stems were only slightly higher in activity. Defoliation of the plants resulted in decreased enzyme activity, increased o-hydroxycinnamic acid content, and essentially no difference in enzyme activity between the genotypes. It appears that phenylalanine ammonia-lyase activity in leaves is not primarily controlled by the Cu/cu alleles and that the reaction catalyzed by this enzyme is not the limiting step in o-hydroxycinnamic acid synthesis.
研究了代表白花苜蓿（Melilotus alba Desr.）CuCu和cucu基因型植株不同部位的提取物中的苯丙氨酸解氨酶活性。与其他植物部位不同，CuCu植株的非常幼嫩的叶片和茎表现出较高的苯丙氨酸解氨酶活性。CuCu植株的初始叶片样本的酶活性约为cucu植株叶片的3倍，但茎的活性仅略高。对植株进行去叶处理导致酶活性降低、邻羟基肉桂酸含量增加，且基因型之间的酶活性基本没有差异。看来叶片中的苯丙氨酸解氨酶活性并非主要受Cu/cu等位基因控制，且该酶催化的反应不是邻羟基肉桂酸合成中的限速步骤。
