Melchior F, Kindl H
University of Marburg, Department of Chemistry, Germany.
Arch Biochem Biophys. 1991 Aug 1;288(2):552-7. doi: 10.1016/0003-9861(91)90234-a.
The mechanisms controlling the induction of stilbene synthase and phenylalanine ammonia-lyase (PAL), two putative key regulatory enzymes of the biosynthetic pathway to stilbene phytoalexins, have been investigated. The induction was studied in cell suspension cultures of grape (Vitis cv. Optima) by treatment with fungal cell wall. Several independent cDNA clones for PAL and stilbene synthase were isolated from a cDNA library of fungal cell wall-induced grape cells and identified by sequence analysis. The stilbene synthase cDNA sequence of pSV21 predicted a protein of 392 amino acids and Mr 42,791, similar in size to that observed experimentally for immunodetected stilbene synthase. The cDNA sequences of pSV21 and pSV25 differed in 76 bp in the coding region. The sequences of grape stilbene synthase cDNAs exhibited significant homology to the sequence reported for the peanut stilbene synthase cDNA. Both PAL and stilbene synthase mRNA, measured by RNA blot hybridizations, were induced within 1 h of addition of fungal cell wall preparations to the cell cultures, rose to a maximum by the sixth hour, then declined slowly over the next 20 h. The activities of PAL and stilbene synthase were also induced in parallel, but reached their maximum at different times after fungal cell wall addition to the cell cultures. The induction patterns of stilbene synthase and PAL in grape and peanut are discussed.
对控制芪合酶和苯丙氨酸解氨酶（PAL）诱导的机制进行了研究，这两种酶被认为是芪类植保素生物合成途径中的关键调控酶。通过用真菌细胞壁处理葡萄（葡萄品种Optima）的细胞悬浮培养物来研究这种诱导作用。从真菌细胞壁诱导的葡萄细胞的cDNA文库中分离出几个独立的PAL和芪合酶cDNA克隆，并通过序列分析进行鉴定。pSV21的芪合酶cDNA序列预测出一个由392个氨基酸组成、分子量为42791的蛋白质，其大小与通过免疫检测法实验观察到的芪合酶相似。pSV21和pSV25的cDNA序列在编码区有76个碱基对的差异。葡萄芪合酶cDNA序列与报道的花生芪合酶cDNA序列具有显著的同源性。通过RNA印迹杂交测量，在向细胞培养物中添加真菌细胞壁制剂后的1小时内，PAL和芪合酶的mRNA均被诱导，在第6小时达到最大值，然后在接下来的20小时内缓慢下降。PAL和芪合酶的活性也同时被诱导，但在向细胞培养物中添加真菌细胞壁后，它们在不同时间达到最大值。文中讨论了葡萄和花生中芪合酶和PAL的诱导模式。
