Sea buckthorn (Hippophae L.) is an economically important shrub or small tree distributed in Eurasia. Most of its well-recognized medicinal and nutraceutical products are derived from its berry oil, which is rich in monounsaturated omega-7 (C16:1) fatty acid and polyunsaturated omega-6 (C18:2) and omega-3 (C18:3) fatty acids. In this study, tandem mass tags (TMT)-based quantitative analysis was used to investigate protein profiles of lipid metabolism in sea buckthorn berries harvested 30, 50, and 70 days after flowering. In total, 8626 proteins were identified, 6170 of which were quantified. Deep analysis results for the proteins identified and related pathways revealed initial fatty acid accumulation during whole-berry development. The abundance of most key enzymes involved in fatty acid and triacylglycerol (TAG) biosynthesis peaked at 50 days after flowering, but TAG synthesis through the PDAT (phospholipid: diacylglycerol acyltransferase) pathway mostly occurred early in berry development. In addition, the patterns of proteins involved in lipid metabolism were confirmed by combined quantitative real-time polymerase chain reaction, enzyme-linked immunosorbent assay, and parallel reaction monitoring analyses. Our data on the proteomic spectrum of sea buckthorn berries provide a scientific basic for understanding lipid metabolism and related pathways in the developing berries.

A 1,697-bp cDNA sequence, designated as PsG6PDH, was amplified from Populus suaveolens. Multiple sequence alignment and phylogenetic analysis indicated that PsG6PDH encodes a cytosolic G6PDH isoform, with Southern blot analysis demonstrating that the gene is single or low copy in Populus. Transgenic tobacco plants over-expressing PsG6PDH exhibited enhanced cold tolerance. In both transgenic and wild-type (WT) tobacco plants, cold stress increased leaf malondialdehyde (MDA) content, electrolyte leakage (EL), and peroxide (POD) and superoxide dismutase (SOD) activities; relative to WT, however, transgenic lines had lower MDA content and EL and higher SOD and POD activities. In addition, PsG6PDH activated the expression of stress-related genes, including NtERD10b, NtERD10c, and NtSOD, in tobacco plants. Our results provide evidence regarding PsG6PDH regulatory function in plants during low temperature stress.

Miscanthus sinensis (Poaceae) is a typical perennial giant grass of East Asia. Due to its high photosynthetic efficiency, low input requirements, and high biomass production, M. sinensis shows outstanding potential as a biofuel feedstock. However, the lack of an efficient tissue culture system may limit its utilization potential. Different explants of M. sinensis were evaluated to develop an efficient tissue culture system. Shoot apices from in vitro-germinated seedling explants were tested for adventitious bud proliferation. The highest level of proliferation (multiplication coefficient 6.69) was obtained when shoot apices were cultured on Murashige and Skoog (MS) medium supplemented with 1.0 mg L −1 6-benzyladenine (BA), 2.0 mg L −1 kinetin, 0.05 mg L −1 α-naphthalene acetic acid (NAA), 3% sucrose, and 0.8% agar. The highest rooting percentage (95.4%) was obtained when adventitious buds were cultured on half-strength MS medium supplemented with 0.2 mg L −1 NAA, 3% sucrose, and 0.8% agar. Significant differences were found in the formation of embryogenic callus among different explant types. The embryogenic callus derived from epicotyls had the highest regeneration capacity when cultured on a medium supplemented with 2.0 mg L −1 2,4-dichlorophenoxyacetic acid, 0.5 mg L −1 BA, and 0.1 mg L −1 thiamine. Under these conditions, the callus induction percentage was 82%.

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