基于转录组测序的杜仲木脂素和木质素生物合成途径及关键酶分析

Identification of key enzyme genes involved in biosynthesis pathways of lignan and lignin in Eucommia ulmoides based on transcriptome assembly

木脂素是杜仲中主要的药用成分,木质素参与植物对病虫害的防御过程,两者的共同前体是松伯醇,然后分别由同化蛋白氧化酶(dirigent, DIR)和过氧化物酶(peroxidases, POD)催化合成。该研究对杜仲茎和叶进行转录组测序,共获得112 578个unigene,其中70 459个被七大公共数据库注释。59个unigene编码木质素、木脂素合成途径11个关键酶,其中11个unigene编码POD,8个unigene编码DIR。13个编码转录因子的unigene参与苯丙素类代谢过程。将杜仲茎和叶中基因表达水平进行比较,有7 575个unigene在杜仲茎中高表达,其中462个unigene涉及苯丙素类生物合成。该研究结果很好地扩展了杜仲转录组数据库,为杜仲木脂素、木质素的生物合成途径解析提供了线索,为进一步研究木质素和木脂素生物合成途径关键酶的功能及调控机制奠定了基础。

Lignan is the main medicinal component of Eucommia ulmoides, and lignin is involved in the defense of plants against diseases and insect pests.They are synthesized from coniferyl alcohol with the help of dirigent(DIR) and peroxidase(POD), respectively.In this study, transcriptome assembly of stems and leaves of E.ulmoides was performed, yielding 112 578 unigenes.Among them, 70 459 were annotated in seven databases.A total of 59 unigenes encodes 11 key enzymes in the biosynthesis pathways of lignin and lignin, of which 11 encode POD and 8 encode DIR.A total of 13 unigenes encoding transcription factors are involved in phenylpropanoid metabolism. Compared with leaves of E.ulmoides, 7 575 unigenes were more highly expressed in stems, of which 462 were involved in phenylpropanoid biosynthesis.Our results extend the public transcriptome dataset of E.ulmoides, which provide valuable information for the analysis of biosynthesis pathways of lignan and lignin in E.ulmoides and lay a foundation for further study on the functions and regulation mechanism of key enzymes in lignan and lignin biosynthesis pathways.