Abstract：
Agave species are typical crassulacean acid metabolism (CAM) plants commonly cultivated to produce beverages, fibers, and medicines. To date, few studies have examined hemicellulose biosynthesis in Agave H11648, which is the primary cultivar used for fiber production. We conducted PacBio sequencing to obtain full-length transcriptome of five agave tissues: leaves, shoots, roots, flowers, and fruits. A total of 41,807 genes were generated, with a mean length of 2394 bp and an annotation rate of 97.12 % using public databases. We identified 42 glycosyltransferase genes related to hemicellulose biosynthesis, including mixed-linkage glucan (1), glucomannan (5), xyloglucan (16), and xylan (20). Their expression patterns were examined during leaf development and fungal infection, together with hemicellulose content. The results revealed four candidate glycosyltransferase genes involved in xyloglucan and xylan biosynthesis, including glucan synthase (CSLC), xylosyl transferase (XXT), xylan glucuronyltransferase (GUX), and xylan α-1,3-arabinosyltransferase (XAT). These genes can be potential targets for manipulating xyloglucan and xylan traits in agaves, and can also be used as candidate enzymatic tools for enzyme engineering. We have provided the first full-length transcriptome of agave, which will be a useful resource for gene identification and characterization in agave species. We also elucidated the hemicellulose biosynthesis machinery, which will benefit future studies on hemicellulose traits in agave.
摘要：
龙舌兰物种是典型的十字花草酸代谢（CAM）植物，通常种植以生产饮料，纤维，和药物。迄今为止,很少有研究检查了龙舌兰H11648中的半纤维素生物合成，龙舌兰是用于纤维生产的主要品种。我们进行了PacBio测序，以获得五个龙舌兰组织的全长转录组：叶，射击，根,鲜花,和水果。总共产生了41,807个基因，使用公共数据库的平均长度为2394bp，注释率为97.12%。我们鉴定了42个与半纤维素生物合成相关的糖基转移酶基因，包括混合键葡聚糖(1)，葡甘露聚糖(5),木葡聚糖(16),和木聚糖(20)。在叶片发育和真菌感染期间检查了它们的表达模式，与半纤维素含量一起。结果揭示了参与木葡聚糖和木聚糖生物合成的四个候选糖基转移酶基因，包括葡聚糖合酶（CSLC），木糖基转移酶（XXT），木聚糖葡糖醛酸转移酶（GUX），和木聚糖α-1,3-阿拉伯糖基转移酶(XAT)。这些基因可以是操纵龙舌兰木葡聚糖和木聚糖性状的潜在靶标，也可作为酶工程的候选酶工具。我们提供了龙舌兰的第一个全长转录组，这将是龙舌兰物种基因鉴定和表征的有用资源。我们还阐明了半纤维素生物合成机制，这将有利于未来对龙舌兰半纤维素性状的研究。
