[Analysis of influencing factors of secondary metabolites contents in cultivated Polygala tenuifolia].

This work was launched to explore the effect of habitat and growth year on the secondary metabolites contents of cultivated Polygala tenuifolia. The samples of cultivated P. tenuifolia were analyzed by ultra-high performance liquid chromatography(UPLC)-quadrupole time-of-flight mass spectrometry(Q-TOF MS), and the obtained data were analyzed using multiple statistical analysis and cluster analysis. The results showed that compared with growth year, habitat is a main influencing factor which affected the secondary metabolites contents of P. tenuifolia. The contents of sucrose esters and oligosacchride multi-esters are greatly dependent on the habitat (the sample-AG with high levels of components of tenuifoliside B and tenuifoliside C, and the sample-FY with high levels of 3,6'-disinapoyl sucrose, tenuifoliose S, tenuifoliose L, and tenuifoliose V). There is no obvious effect of habitat and growth year on xanthone. The contents of triterpene saponins are greatly dependent on the growth year, and the content of parts of triterpene saponins increased as time goes on.The result indicated that the effect of habitat and growth year on different types of secondary metabolites is not completely equivalent. This study will contribute to the breeding of P. tenuifolia and amendment of current commodity criteria.

Isolation and differential expression of a novel MAP kinase gene DoMPK4 in Dendrobium officinale.

Mitogen-activated protein kinases (MAPKs) are important signaling transduction components well conserved in eukaryotes and play essential roles in various physiological, developmental and hormonal responses in plant. In the present study, a MAPK gene, designated as DoMPK4 (GenBank accession No. JX297597), is identified from a rare endangered medicinal orchid species D. officinale using the reverse transcription polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE) methods. The full length cDNA of DoMPK4 is 1 518 bp in length and encoded a 369 aa protein with a molecular weight of 42.42 kD and an isoelectric point of 5.55. DoMPK4 protein contained a serine/threonine protein kinase active site (158-170), a MAP kinase site (71-174), and eight conserved motifs. DoMPK4 had a transmembrane (214-232) but no signal peptide. Multiple sequence alignment showed that DoMPK4 shared high identities (74.9%-80.6%) with MAPK proteins from various plants. Phylogenetic analysis demonstrated that DoMPK4 belonged to group A of the MAPK evolutionary tree, and is closely related to monocots. Real time quantitative PCR (qPCR) analysis revealed that DoMPK4 is differentially expressed among the five organs including leaf, stem, root, seed, and protocorm-like body (PLB). The transcription level of DoMPK4 is the highest in the PLBs with 17.65 fold, followed by seeds, roots, and stems with 5.84, 2.28, and 1.64 fold, respectively. The progressive enhancement of DoMPK4 transcripts in the developing PLBs compared to that in the germinating seeds, suggests a role of DoMPK4 during the development of embryogenic PLBs formation in D. officinale.