The genus Peronospora, an obligate biotrophic group belonging to Oomycota, causes serious damage to a variety of wild and ornamental plants, as well as cultivated crops, such as beet, rose, spinach, and tobacco. To investigate the diversity of Peronospora species parasitic to Stellaria and Pseudostellaria (Caryophyllaceae) plants in Korea, we performed a morphological analysis on dried herbarium specimens and molecular phylogenetic inferences based on internal transcribed spacer rDNA and cox2 mitochondrial DNA sequences. As a result, it was confirmed that there are four species of Peronospora parasitic to specific species of Stellaria and Pseudostellaria, all of which were hitherto unrecorded in Korea: P. alsinearum (ex Stellaria media), P. stellariae-aquaticae (ex Stellaria aquatica), P. stellariae-uliginosae (ex Stellaria alsine), and P. pseudostellariae (ex Pseudostellaria palibiniana). In addition, Peronospora specimens parasitic to Pseudostellaria davidii differed morphologically from P. pseudostellariae owing to the large and ellipsoidal conidia; this morphological discrepancy was also validated by the high genetic divergence between the two species. Peronospora casparyi sp. nov. is described and illustrated here.
Beta vulgaris ; Caryophyllaceae ; Classification* ; DNA, Mitochondrial ; DNA, Ribosomal ; Host Specificity ; Korea* ; Oomycetes ; Peronospora* ; Phylogeny* ; Spinacia oleracea ; Spores, Fungal ; Stellaria* ; Tobacco

OBJECTIVETo study the chemical constituents of Stellaria media.

METHODThe compounds were isolated with various column chromatography and semi-preparative HPLC. The structures were determined by modem spectroscopic methods (IR, UV, 1H-NMR, 13C-NMR, HMBC, ESI-MS).

RESULTFive compounds were isolated and identified as apigenin 6-C-beta-D-galactopyranosyl-8-C-alpha-L-arabinopyranoside (1), apigenin 6-C-alpha-L-arabinopyranosyl-8-C-beta-D-galactopyranoside (2), apigenin 6-C-beta-D-galactopyranosyl-8-C-beta-L-arabinopyranoside (3), apigenin 6-C-beta-D-glucopyranosyl-8-C-beta-D-galactopyranoside (4), apigenin 6, 8-di-C-alpha-L-arabinopyranoside (5).

CONCLUSIONCompounds 1-5 were obtained from Stellaria genus for the first time.

Apigenin ; chemistry ; isolation & purification ; Chromatography, High Pressure Liquid ; methods ; Flavones ; chemistry ; isolation & purification ; Galactosides ; chemistry ; isolation & purification ; Plants, Medicinal ; chemistry ; Stellaria ; chemistry

A pot experiment was conducted to study effect of drought stress on leaf physiological characteristics and growth of one year old Stellaria dichotoma seedlings. The result showed that plant height and shoot dry weight significantly decreased with decrease in soil water content; however, root length and root dry weight increased at light drought stress and decreased at severe drought stress. The result also showed that with the decrease of soil water content, proline content in S. dichotoma leaves decreased then increase, while solube protein content decreased. Activities of SOD and POD in S. dichotoma leaves significantly decreased as soil water content decreased, while activity of CAT significantly decreased at severe drought stress. Membrane permeability in S. dichotoma leaves increased, while MDA content decreased then increased as soil water decreased. These results suggest that S. dichotoma had osmotic stress resistance ability and reactive oxygen scavenging capacity at light drought stress, which caused S. dichotoma growth was no inhibited at a certain extent drought stress.
Droughts ; Plant Leaves ; enzymology ; growth & development ; metabolism ; Plant Proteins ; metabolism ; Plant Roots ; enzymology ; growth & development ; metabolism ; Proline ; metabolism ; Seedlings ; enzymology ; growth & development ; metabolism ; Stellaria ; enzymology ; growth & development ; metabolism ; Water ; metabolism