RESUMEN
HMGR and DXR are key enzymes of terpenoids biosynthesis pathway. This study was aimed to discuss the effects of overexpression of HMGR and DXR from A momum villosum Lour. on the biosynthesis of terpenoids in transgenic tobacco. The real-time fluorescence quantitative PCR (RT-qPCR) was used to analyze the expression level of AvHMGR and AvDXR. Then, enzyme activities of HMGR and DXR were determined by spectrometer using the substrate-specific method. Different terpenoids were detected by GC-MS. The results showed that individual overex-pression of HMGR/DXR can inhibit the enzyme activities of HMGR and DXR but promote the biosynthesis of men-thene, neophytediene, cembrenene and sterol. The co-overexpression of HMGR and DXR had different enzyme activ-ities and can promote the biosynthesis of sterol and phytol, but inhibit the biosynthesis of neophytadiene. It was con-cluded that the overexpression of HMGR and DXR had diverse effects when regulating the biosynthesis of different terpenoids. This study provided the basis for using A vHMGR and A vDXR to regulate the metabolism of terpenoids.
RESUMEN
This study was aimed to reveal the effects and molecular regulation mechanism of methyl jasmonate (Me-JA) on volatile terpenoids from Amomum villosum Lour. After the leaves and fruits of A momum villosum Lour. were treated with different concentrations of MeJA, the volatile terpenoids of fresh fruits from A . villosum Lour. were ex-tracted with microwave method and analyzed by GC-MS. Then, leaves and fruits treated with MeJA were sequenced by Illumina. The transcriptome data was analyzed by bioinformatic methods. The results showed that there were 20 and 33 volatile terpenoids detected in peels and seed groups, respectively. Contents of volatile terpenoids in peels and seed groups were both improved after 600 μmol·L-1 MeJA treating fruits for 24 h, such as bornyl acetate, cam-phor, borneol, and etc. While 200 μmol·L-1 MeJA treating different parts for 24 h can regulate the biosynthesis of some volatile terpenoids in peels differently. And 200 μmol·L-1 MeJA treating fruits can improve the content of ma-jor volatile terpenoids in seed groups. A total of 68 168 unigenes were obtained with de novo assembly, and 48 627 unigenes were annotated after comparison with public protein databases. Analysis of functional annotation against KEGG database showed that there were 208 unigenes closely related with metabolism of volatile terpenoids and 22 u-nigenes related with MYC2 transcription factors. It was concluded that MeJA can effectively regulate the metabolism of volatile terpenoids from A . villosum Lour. There were a lot of candidate genes related with the biosynthesis of volatile terpenoids obtained by analyzing the transcriptome data which also provided a large amount of data for the discovery and regulation of functional genes related with the biosynthesis of volatile terpenoids from A . villosum Lour.
RESUMEN
This study was aimed to discuss the dynamic variation of soluble sugar contents, sucrose metabolizing en-zyme activities and gene expression quantities during the fruits development of A momum villosum, in order to pro-vide the basis of improvement of the fruit yield. Fresh fruits at three different development processes (30 DAF, 60 DAF, 90 DAF) were used to investigate changes of soluble sugar components and sucrose metabolizing enzyme activ-ities by HPLC and UV spectrophotometry. Combining with the high-throughput sequencing expression profile data of three fruit development period, the trends of three key enzymes gene expressed in sugar metabolism were analyzed. The results showed that the fruit sugar components were dominated by fructose, glucose and sucrose. The concentra-tion of hexose (fructose and glucose) gradually decreased in peel. But in seeds the concentration of hexose decreased at first and then increased. The content of sucrose and the net activities of sucrose synthase (synthesizing direction minus decomposing direction) in peel and seeds were gradually increased. The expression trends of key enzyme gene in sugar metabolism examined by RNA-seq quantification showed that sucrose phosphate synthase and sucrose syn-thase gene increased and then kept constant, but the invertase gene expression trend was gradually rising. Conse-quently, sucrose synthase was the key enzyme catalyzing sucrose synthesis and decomposition. The activity of sucrose synthase and sucrose contents in peel and seeds reached the highest peak in the end of fruit mature.