Novel Antioxidants Isolated from Perilla frutescens Britton var. crispa (Thunb.)

Two novel antioxidants (vinyl caffeate and trans-p-menth-8-en-7-yl caffeate) and seven known antioxidants (3,4-dihydroxybenzaldehyde, methyl 3,4-dihydroxy-benzoate, methyl caffeate, 3′,4′,5,7-tetra-hydroxy-flavone, caffeic acid, 6,7-dihydroxycoumarin, and rosmarinic acid) were isolated from Perilla frutescens Britton var. crispa (Thunb.). The redox potentials of the novel isolated antioxidative compounds were comparable to those of known antioxidants. trans-p-menth-8-en-7-yl caffeate was effective to prevent the oxidative degradation of perillaldehyde in the essential oil of P. frutescens.     

Hormonal Control of Morphogenesis in Leaf Explants of Perilla frutescens Britton var. crispa Decaisne f. viridi-crispa Makino

Leaf discs of Perilla frutescens var. crispa f. viridi-crispawere cultured on a defined medium to investigate factors influencingbud and root formation, callus induction, somatic embryogenesis,and floral bud formation. Addition of naphthalene-acetic acid(NAA) to the culture medium caused compact callus whereas 2,4-dichlorophenoxyacetic acid (2,4-D) promoted soft and friable callus formationon the surface of the explants. Benzyladenine, when appliedwith auxin, suppressed callus and root formation. Somatic embryogenesisoccurred, when the explants were first grown on nutrient mediumcontaining 2,4-D and organic elements, and then transferredto the 2,4-D free medium. Treatments with cytokinins, N-phenyl-N'-(4-pyridyl)urea and its derivatives induced bud formation. A low concentrationof NAA and naphthoxy-acetic acid promoted bud development. Occasionalfloral bud formation was observed depending on the originalleaf positions on mother plants from which the leaf discs wereexcised. A gradient of floral bud forming capacity along thestem was noted. Perilla frutescens, tissue culture, embryogenesis, morphogenesis, benzyl adenine, kinetin, naphthalene-acetic acid, naphthoxy-acetic acid, 2,4-dichlorophenoxy acetic acid, indol-3yl-acetic acid, cytokinins, auxins     

De Novo Assembly and Functional Annotation of the Olive (Olea europaea) Transcriptome

Olive breeding programmes are focused on selecting for traits as short juvenile period, plant architecture suited for mechanical harvest, or oil characteristics, including fatty acid composition, phenolic, and volatile compounds to suit new markets. Understanding the molecular basis of these characteristics and improving the efficiency of such breeding programmes require the development of genomic information and tools. However, despite its economic relevance, genomic information on olive or closely related species is still scarce. We have applied Sanger and 454 pyrosequencing technologies to generate close to 2 million reads from 12 cDNA libraries obtained from the Picual, Arbequina, and Lechin de Sevilla cultivars and seedlings from a segregating progeny of a Picual × Arbequina cross. The libraries include fruit mesocarp and seeds at three relevant developmental stages, young stems and leaves, active juvenile and adult buds as well as dormant buds, and juvenile and adult roots. The reads were assembled by library or tissue and then assembled together into 81 020 unigenes with an average size of 496 bases. Here, we report their assembly and their functional annotation.     

Flowering induced by 5-azacytidine, a DNA demethylating reagent in a short-day plant, Perilla frutescens var. crispa

Treatment with 5-azacytidine, a DNA demethylating reagent, induced flowering in Perilla frutescens (L.) Britton var. crispa (Thunb. ex Murray) Decne. ex L. H. Bailey, an absolute short-day plant under long days. The 5-azacytidine treatment induced slight suppression of vegetative growth but had no obvious effect on any other phenotypes. The Southern hybridization analysis of the genomic DNA isolated from the leaves of 5-azacytidine-treated plants and digested with restriction enzyme, methylation-insensitive Msp I or methylation-sensitive Hpa II with P. frutescens 25S-18S rDNA intergenic spacer probe indicated that the 5-azacytidine treatment caused demethylation of the genomic DNA. The 5-azacytidine-induced flowering was delayed as compared with the short day-induced flowering. Flowers were formed even at the lower nodes which had not been directly treated with 5-azacytidine. The results suggest that DNA demethylation induced flowering by inducing the production of a transmissible flowering stimulus in P. frutescens .