Am J Bot. 1998 Jul;85(7):997.
The phytochemical system of mustard-oil glucosides (glucosinolates) accompanied by the hydrolytic enzyme myrosinase (beta-thioglucosidase), the latter usually compartmented in special myrosin cells, characterizes plants in 16 families of angiosperms. Traditional classifications place these taxa in many separate orders and thus imply multiple convergences in the origin of this chemical defense system. DNA sequencing of the chloroplast rbcL gene for representatives of all 16 families and several putative relatives, with phylogenetic analyses by parsimony and maximum likelihood methods, demonstrated instead a single major clade of mustard-oil plants and one phylogenetic outlier. In a further independent test, DNA sequencing of the nuclear 18S ribosomal RNA gene for all these exemplars has yielded the same result, a major mustard-oil clade of 15 families (Akaniaceae, Bataceae, Brassicaceae, Bretschneideraceae, Capparaceae, Caricaceae, Gyrostemonaceae, Koeberliniaceae, Limnanthaceae, Moringaceae, Pentadiplandraceae, Resedaceae, Salvadoraceae, Tovariaceae, and Tropaeolaceae) and one outlier, the genus Drypetes, traditionally placed in Euphorbiaceae. Concatenating the two gene sequences (for a total of 3254 nucleotides) in a data set for 33 taxa, we obtain robust support for this finding of parallel origins of glucosinolate biosynthesis. From likely cyanogenic ancestors, the "mustard oil bomb" was invented twice.
芥子油葡萄糖苷（硫代葡萄糖苷）的植物化学系统伴随着水解酶糜蛋白酶（β-硫葡萄糖苷酶），后者通常位于特殊的糜蛋白酶细胞中，这一特征存在于被子植物的 16 个科中。传统的分类将这些分类单元置于许多不同的目，这意味着这种化学防御系统的起源有多次趋同。对来自 16 个科的所有代表植物和几个假定的近亲的叶绿体 rbcL 基因进行 DNA 测序，并通过简约法和最大似然法进行系统发育分析，结果表明芥子油植物只有一个主要的分支，并且只有一个系统发育上的离群值。在另一个独立的测试中，对所有这些标本的核 18S 核糖体 RNA 基因进行 DNA 测序也得到了相同的结果，即一个主要的芥子油分支包括 15 个科（Akaniaceae、Bataceae、Brassicaceae、Bretschneideraceae、Capparaceae、Caricaceae、Gyrostemonaceae、Koeberliniaceae、Limnanthaceae、Moringaceae、Pentadiplandraceae、Resedaceae、Salvadoraceae、Tovariaceae 和 Tropaeolaceae）和一个离群值，即 Drypetes 属，传统上被置于大戟科中。将两个基因序列（共 3254 个核苷酸）串联在一个包含 33 个分类单元的数据集上，我们得到了对硫代葡萄糖苷生物合成平行起源这一发现的强有力支持。从可能的氰苷祖先开始，“芥子油炸弹”被发明了两次。
