Barceló Alfonso Ros, Ros Laura V Gómez, Carrasco Alberto Esteban
Department of Plant Biology, University of Murcia, E-30100 Murcia, Spain.
Department of Plant Biology, University of Murcia, E-30100 Murcia, Spain.
Trends Plant Sci. 2007 Nov;12(11):486-491. doi: 10.1016/j.tplants.2007.09.002. Epub 2007 Oct 24.
Lignins are cell wall heteropolymers that arise from the peroxidase-mediated coupling of p-coumaryl, coniferyl and sinapyl alcohols. In gymnosperms, they are derived from coniferyl alcohol, whereas in angiosperms, lignins are derived from coniferyl and sinapyl alcohols. Thus, although it is frequently assumed that the chemical complexity of lignins has increased during plant evolution, it is frequently forgotten that pteridophytes have lignins that are derived from sinapyl alcohol. Until recently, most peroxidases characterized in flowering plants only oxidized coniferyl alcohol. However, recent reports have described the molecular characterization of peroxidases capable of oxidizing sinapyl alcohol (syringyl peroxidases). Current molecular studies propose that the structural motifs of syringyl peroxidases predate the radiation of tracheophytes, which suggests that syringyl peroxidases existed before the appearance of syringyl lignins.
木质素是细胞壁杂聚物,由对香豆醇、松柏醇和芥子醇在过氧化物酶介导下偶联而成。在裸子植物中,它们源自松柏醇,而在被子植物中,木质素源自松柏醇和芥子醇。因此,尽管人们常常认为木质素的化学复杂性在植物进化过程中有所增加,但却常常忘记蕨类植物的木质素源自芥子醇。直到最近,大多数在开花植物中鉴定出的过氧化物酶仅氧化松柏醇。然而,最近的报道描述了能够氧化芥子醇的过氧化物酶(紫丁香基过氧化物酶)的分子特征。目前的分子研究表明,紫丁香基过氧化物酶的结构基序早于维管植物的辐射,这表明紫丁香基过氧化物酶在紫丁香基木质素出现之前就已存在。