The Paeonia root, with or without bark, are considered vital traditional Chinese medicine materials; the examples are those of Bai Shao, Chi Shao,and Dan Pi. In this study, we examine 24 genes and their expressions involved in the biosynthesis ofpaeoniflorin and its derivatives, which are active compounds of the Paeonia root, in Paeonialactiflora and P. suffruticosa, as well as other related plants, Punica granatum, Rhus radicans, and Coriaria nepalensis. Our phylogenetic analyses suggest that these genes have functional diversity, and analysis of the transcriptional level shows paeoniflorin and gallic acid biosynthesis-related genes exhibit different transcription profiles in flowers, carpels, bark-free roots, and bark of P. lactiflora. The correlation analysis of gene expression and active compound contents support the idea that hydroxymethylglutaryl-CoA synthase and phosphomevalonate kinase in the mevalonate pathway and 3-dehydroquinate dehydratase/shikimate dehydrogenase in shikimate biosynthesis are potentially closely related to the accumulation of paeoniflorin and benzoylpaeoniflorin. Coupling gene diversity with chemical analysis, we show that paeoniflorin and its derived aromatic amino acids are predominant in bark.
Non-Camellia tea is a part of the colorful Chinese tea culture, and is also widely used as beverage and medicine in folk for disease prevention and treatment. In this study, 37 samples were collected, including 33 kinds of non-Camellia teas and 4 kinds of teas (Camellia). Traditional functions of non-Camellia teas were investigated. Furthermore, non-Camellia teas of original plants were characterized and identified by molecular methods. Four candidate regions (rbcL, matK, ITS2, psbA-trnH) were amplified by polymerase chain reaction. In addition, DNA barcodes were used for the first time to discriminate the commercial non-Camellia tea and their adulterants, and to evaluate their safety. This study showed that BLASTN and the relevant phylogenetic tree are efficient tools for identification of the commercial non-Camellia tea and their adulterants. However, some sequences from original plants have not been found and there is a limitation of sequence number of original plants in GenBank. Submitting more original plant sequences to the GenBank will be helpful for evaluating the safety of non-Camellia teas.
4-Coumarate:CoA ligases (4CLs) are a group of essential enzymes involved in the pathway of phenylpropanoid-derived compound metabolisms; however it is still difficult to identify orthologs and paralogs of these important enzymes just based on sequence similarity of the conserved domains. Using sequence data of 20 plant species from the public databases and sequences from Lonicera japonica, we define 1252 adenosine monophosphate (AMP)-dependent synthetase/ligase sequences and classify them into three phylogenetic clades. 4CLs are in one of the four subgroups, according to their partitioning, with known proteins characterized in A. thaliana and Oryza sativa. We also defined 184 non-redundant sequences that encode proteins containing the GEICIRG motif and the taxonomic distribution of these GEICIRG-containing proteins suggests unique catalytic activities in plants. We further analyzed their transcription levels in L. japonica and L. japonica. var. chinensis flowers and chose the highest expressed genes representing the subgroups for structure and binding site predictions. Coupled with liquid chromatography-mass spectrometry (LC-MS) analysis of the L. japonica flowers, the structural study on putative substrate binding amino acid residues, ferulate, and 4-coumaric acid of the conserved binding-site of LJ4CL1 leads to a conclusion that this highly expressed protein group in the flowers may process 4-coumarate that represents 90% of the known phenylpropanoid-derived compounds. The activity of purified crude LJ4CL1 protein was analyzed using 4-coumarate as template and high activity indicating that 4-coumarate is one of the substrates of LJ4CL1.
Salvia miltiorrhiza (S. miltiorrhiza) Bunge is one of the most economically important medicinal crops in China. In traditional Chinese medicine, its root is used as an important ingredient in formulas for treatment of atherosclerosis-related disorders. The continuous cropping of S. miltiorrhiza increases the proportion of dried seedlings and decreases the biomass of the shoots and roots and the contents of active components. In this study, three field experiments were conducted to investigate the effects of Glomus mosseae (G. mosseae) inoculation on the growth and contents of active ingredients and nutrients in continuously cropped S. miltiorrhiza. The results showed that inoculation with G. mosseae increased the shoot biomass of S. miltiorrhiza by 48.1% and the root biomass by 39.2%, and decreased the dried seedling rate by nearly 75%. Inoculation with G. mosseae also increased the salvianolic acid B concentration by 21.9% in the shoots and 9.2% in the roots of S. miltiorrhiza, and also significantly increased Mn concentration in the roots and shoots (by 65.1% and 93.4%, respectively) and Fe concentration in the roots (by 75%). The accumulation of salvianolic acid B, Mn, and Fe in G. mosseae inoculated S. miltiorrhiza may be a mechanism that imparts tolerance to continuous cropping. Inoculation of S. miltiorrhiza with G. mosseae can serve as an effective approach of biocontrol to improve the performance of continuously cropped S. miltiorrhiza.