Gomez-Vargas Alan D, Hernández-Martínez Karen M, López-Rosas Macrina E, Alejo Jacuinde Gerardo, Simpson June
Department of Genetic Engineering, CINVESTAV Irapuato, Km. 9.6 Libramiento Norte Carretera Irapuato-León, Irapuato 36821, Guanajuato, Mexico.
Plants (Basel). 2022 Aug 19;11(16):2153. doi: 10.3390/plants11162153.
Plant Glycoside Hydrolase Family 32 (PGHF32) contains the fructosyltransferases and fructan exohydrolase enzymes responsible for fructan metabolism, in addition to closely related vacuolar and cell wall acid invertases. species produce complex and dynamic fructan molecules (agavins) requiring 4 different fructosyltransferase activities (1-SST, 1-FFT, 6G-FFT and 6-SFT) for their synthesis. Combined analysis of RNAseq and genome data for led to the characterization of the genes encoding 3 fructosyltransferases for this species and support the hypothesis that no separate 6-SFT type enzyme exists in suggesting that at least one of the fructosyltransferases identified may have multiple enzymatic activities. Structures for PGHF32 genes varied for and between other plant species but were conserved for different enzyme types within a species. The observed patterns are consistent with the formation of distinct gene structures by intron loss. Promoter analysis of the PGHF32 genes identified abundant putative regulatory motifs for light regulation and tissue-specific expression, and these regulatory mechanisms were confirmed experimentally for leaf tissue. Motifs for phytohormone response, carbohydrate metabolism and dehydration responses were also uncovered. Based on the regulatory motifs, full-length cDNAs for MYB, GATA, DOF and GBF transcription factors were identified and their phylogenetic distribution determined by comparison with other plant species. In silico expression analysis for the selected transcription factors revealed both tissue-specific and developmental patterns of expression, allowing candidates to be identified for detailed analysis of the regulation of fructan metabolism in at the molecular level.
植物糖苷水解酶家族32（PGHF32）除了包含与液泡和细胞壁酸性转化酶密切相关的果糖基转移酶和果聚糖外切水解酶外，还含有负责果聚糖代谢的酶。一些物种产生复杂且动态的果聚糖分子（龙舌兰果聚糖），其合成需要4种不同的果糖基转移酶活性（1-SST、1-FFT、6G-FFT和6-SFT）。对[物种名称]的RNA测序和基因组数据进行综合分析，确定了该物种编码3种果糖基转移酶的基因特征，并支持了[物种名称]中不存在单独的6-SFT型酶这一假设，这表明所鉴定的果糖基转移酶中至少有一种可能具有多种酶活性。PGHF32基因的结构在[物种名称]和其他植物物种之间有所不同，但在一个物种内不同酶类型中是保守的。观察到的模式与内含子缺失形成独特基因结构一致。对PGHF32基因的启动子分析确定了大量用于光调节和组织特异性表达的假定调控基序，并且这些调控机制已在叶组织中通过实验得到证实。还发现了植物激素反应、碳水化合物代谢和脱水反应的基序。基于这些调控基序，鉴定了MYB、GATA、DOF和GBF转录因子的全长cDNA，并通过与其他植物物种比较确定了它们的系统发育分布。对所选转录因子的电子表达分析揭示了组织特异性和发育表达模式，从而能够鉴定出候选因子，以便在分子水平上详细分析[物种名称]中果聚糖代谢的调控。
