Phylogeny and functional characterization of the cinnamyl alcohol dehydrogenase gene family in Phryma leptostachya
Phylogeny and functional characterization of the cinnamyl alcohol dehydrogenase gene family in Phryma leptostachya
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DOI：
10.1016/j.ijbiomac.2022.07.063
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发表时间：
2022-07-15
影响因子：
8.2
通讯作者：
Hu, Zhaonong
中科院分区：
文献类型：
--
作者：
Li, Yankai;Pei, Yakun;Hu, Zhaonong
细穗Phryma leptostachya因其富含呋喃木脂素类化合物，具有广泛的生物活性而日益受到人们的关注。呋喃木脂素的生物合成始于单萜醇之一松柏醇的二聚。肉桂醇脱氢酶（CAD）催化肉桂醇生物合成的最后一步，将肉桂醛还原为肉桂醇。由于它处于单萜醇生物合成的末端位置，其类型和活性可引起木脂素总量和组成的显著变化。结合生物信息学分析和体外酶活性测定，明确了密竹CAD基因属于一个多基因家族，并鉴定了几乎整个CAD基因家族。对两种主要CAD异构体PlCAD 2和PlCAD 3的功能和结构进行了深入的表征，结果表明PlCAD 2表现出最高的催化活性，松柏醛是其优选底物，其次是PlCAD 3，芥子醛是其优选底物。考虑到呋喃木脂素的积累模式和PlCAD的表达模式，我们推测PlCAD 2是细穗松中负责呋喃木脂素生物合成的主要CAD亚型。此外，这些CAD还可以为木脂素和木质素的生物合成提供有效的生物活性部位。
Phryma leptostachya has attracted increasing attention because it is rich in furofuran lignans with a wide range of biological activities. Biosynthesis of furofuran lignans begins with the dimerization of coniferyl alcohol, one of the monolignol. Cinnamyl alcohol dehydrogenase (CAD) catalyzes the final step of monolignol biosynthesis, reducing cinnamyl aldehydes to cinnamyl alcohol. As it is in the terminal position of monolignol biosynthesis, its type and activity can cause significant changes in the total amount and composition of lignans. Herein, combined with bioinformatics analysis and in vitro enzyme assays, we clarified that CAD in P. leptostachya belonged to a multigene family, and identified nearly the entire CAD gene family. Our in-depth characterization about the functions and structures of two major CAD isoforms, PlCAD2 and PlCAD3, showed that PlCAD2 exhibited the highest catalytic activity, and coniferyl aldehyde was its preferred substrate, followed by PlCAD3, and sinapyl aldehyde was its preferred substrate. Considering the accumulation patterns of furofuran lignans and expression patterns of PlCADs, we speculated that PlCAD2 was the predominant CAD isoform responsible for furofuran lignans biosynthesis in P. leptostachya. Moreover, these CADs found here can also provide effective biological parts for lignans and lignins biosynthesis.