Linum persicum: Lignans and placement in Linaceae†

Aryltetralin lignans (podophyllotoxin type) are the main lignan constituents of species belonging to Linum section Syllinum (Linaceae). Linum persicum, a perennial plant native to Iran closely related to L. album, has not yet been studied. To evaluate the lignan profile, fresh plants of L. persicumwere collected and divided into different parts and analyzed by HPLC. The main aryltetralin lignans found inL. persicumplant parts, callus and cell cultures were podophyllotoxin (PTOX), 6-methoxypodophyllotoxin (MPTOX) and - and -peltatin. Furthermore, the systematic relationship between L. persicum and other Linum species are discussed in the light of morphological and phytochemical aspects. Abbreviations: MPTOX – 6-methoxypodophyllotoxin; PTOX – podophyllotoxin; DOP – deoxypodophyllotoxin.     

Genomic characterization of self-incompatibility ribonucleases in the Central Asian pear germplasm and introgression of new alleles from other species of the genus Pyrus

The Pyrus species exhibit the so-called S-RNase-based gametophytic self-incompatibility system, which is considered to be the most widespread self-incompatibility system among flowering plants. In this study, 57 Iranian pear (Pyrus communis L.) domestic cultivars and wild genotypes, plus 21 European pear cultivars used as references, were genotyped adopting a PCR-based genotyping assay using consensus and allele-specific primers. The results revealed traces of significant genetic contribution in the Iranian traditional varieties and genotypes from other Pyrus species; the genetic contribution of Japanese pear clearly emerged with the detection of some Pyrus pyrifolia S-RNase alleles. Moreover, our results highlighted the presence of three new S-RNase alleles (named S₁₂₆, S₁₂₇, and S₁₂₈) that were not previously identified in P. communis, possibly introduced in the germplasm of cultivated pear through gene transfer from other cultivated or wild species.     

Lignans in flowering aerial parts of Linum species – Chemodiversity in the light of systematics and phylogeny

The aerial parts of 54 accessions representing 41 Linum species and four species of related genera were analysed for lignans by means of HPLC-ESI/MS–MS-UV/DAD. In total, 64 different lignans of the aryltetralin-, arylnaphthalene-, aryldihydronaphthalene-, dibenzylbutyrolactone-, and furofuran type were identified. According to their lignan profile, the Linum species can be divided in two groups accumulating as major lignan types either cyclolignans of the aryltetralin-series on one hand, or aryldihydronaphthalenes/arylnaphthalenes, on the other. Five of the investigated Linum species did not contain any detectable amounts of these lignans under the chosen analytical conditions. Furthermore, none of the lignans identified in Linum species was detectable in representatives of three related genera, namely, Reinwardtia (Linaceae, Linoideae), Hugonia and Indorouchera (Linaceae, Hugonioideae).The two species groups differing in the types of the dominating cyclolignans comprise representatives of the major taxonomic sections. Representatives of sections Syllinum, Cathartolinum and Linopsis accumulate mainly aryltetralins while those of sections Linum and Dasylinum were found to contain mainly aryldihydronaphthalenes/-naphthalenes. These phytochemical data correlate very well with a recent study on the molecular phylogeny of Linum/Linaceae, where a subdivision of Linum into two major clades comprising representatives of the two mentioned groups was found. Thus, the distribution of lignans apparently reflecting phylogenetic interrelations at the infrageneric level, a plausible scenario for the evolution of lignan biosynthesis in the genus Linum can now be presented.     

Linum mucronatum: organ to organ lignan variations

The percentage of podophyllotoxin (PTOX) and its congener lignans were measured by HPLC in Linum mucronatum ssp. mucronatum (Linaceae) fresh plant organs. The highest amounts of PTOX (0.595 +/- 0.060% g/g dry wt) and 6-methoxypodophyllotoxin (MPTOX) (1.491 +/- 0.125% g/g dry wt) were found in the plant sexual organs. Whereas, the highest levels of beta-peltatin, 5'-demethoxy-MPTOX and yatein were found in not developed buds, petals and sepals, respectively.     

Real-time polymerase chain reaction assays for rapid detection and virulence evaluation of the environmental Pseudomonas aeruginosa isolates

Molecular Biology Reports - Rapid and species-specific detection, and virulence evaluation of opportunistic pathogens such as Pseudomonas aeruginosa, are issues that increasingly has attracted the...     

Genetic Variation and Structure in Natural Populations of a Medicinal Vegetable,Satureja bachtiarica,Inferred from Microsatellite Markers Developed Using Next-Generation Sequencing

Plant Molecular Biology Reporter - Satureja bachtiarica Bunge (Lamiaceae) is a medicinal plant native to Iran which is widely used in traditional medicine, as a spice and as a vegetable....     

Root cultures of linum species section Syllinum as rich sources of 6-methoxypodophyllotoxin

Linum spp. from section Syllinum are promising for the production of aryltetralin lignans like podophyllotoxin (PTOX) and 6-methoxypodophyllotoxin (MPTOX). MPTOX is a PTOX congener that has cytotoxic activity comparable with PTOX. In this study root cultures of Linum Bungei from section Dasyllinum, L. strictum from section Linastrum, L. album, L. mucronatum ssp. mucronatum and L. nodiflorum from section Syllinum were established and their MPTOX levels were investigated in 1000 ml flasks. Root cultures of L. mucronatum ssp. mucronatum and L. nodiflorum were used to examine cell growth and production of MPTOX during a culture period of 36 days in 250 ml flasks. Considerable amounts of MPTOX in root cultures (1000 ml flasks) of L. album (6 mg/100 g DW), L. mucronatum ssp. mucronatum (770 mg/100 g DW) and L. nodiflorum (91 mg/100 g DW) were detected while it wasn't detected in root cultures of L. Bungei and L. strictum. In time course experiments, the maximum amount of MPTOX in L. nodiflorum root culture was at day 16 with 480 mg/ 100 g DW and the maximum amount of MPTOX in L. mucronatum ssp. mucronatum root culture was at day 12 with 130 mg/100 g DW. The results showed that root cultures of Linum species from section Syllinum are rich sources of MPTOX and since this lignan has remarkable cytotoxic activity, it can be used as a precursor for the production of antitumor agents.