Humphreys John M, Chapple Clint
Department of Biochemistry, Purdue University, West Lafayette, Indiana 47907, USA.
Curr Opin Plant Biol. 2002 Jun;5(3):224-9. doi: 10.1016/s1369-5266(02)00257-1.
Considerable interest in lignin biosynthesis has been fueled by the many roles that lignin plays in development and in resistance to biotic and abiotic stress, as well as its importance to industry and agriculture. Although the pathway leading to the lignin polymer has been studied for decades, new insights into the enzymes of the pathway have required a complete re-evaluation of how we think lignin precursors are synthesized. Although free hydroxycinnamic acids have long been thought to be key intermediates, it has become apparent that many of the hydroxylation and methylation steps in the pathway occur instead at the level of hydroxycinnamic acid esters, and their corresponding aldehydes and alcohols.
木质素在植物发育、抵抗生物和非生物胁迫中发挥着多种作用，并且对工农业具有重要意义，这引发了人们对木质素生物合成的浓厚兴趣。尽管通往木质素聚合物的途径已经研究了数十年，但对该途径中酶的新见解要求我们对木质素前体的合成方式进行全面重新评估。虽然游离羟基肉桂酸长期以来一直被认为是关键中间体，但很明显，该途径中的许多羟基化和甲基化步骤实际上发生在羟基肉桂酸酯及其相应的醛和醇水平上。
