The sugar content of grape berries is affected by many factors. To explore the hexose content in different cultivars, the photosynthesis, vegetative, and reproductive biomass, as well as the enzyme activities and expression levels of genes related to sugar metabolism and sugar contents were measured. Samples were collected 70-110 days after anthesis (DAA), from Riesling (RI), Petit Manseng (PM), and Cabernet Sauvignon (CS) berries cultivated in the field. The results indicated that high expression levels of VvSWEET15 and VvSS3 and a high activity of sucrose synthase (SS) are associated with a higher hexose content in the berries of PM than in the berries of the other two cultivars. These genes promoted hexose accumulation in the berries by regulating sugar hydrolysis and transport. The results of this study indicate that active sugar hydrolysis and transport increase the hexose content of PM berries, which provides insights for grape berry quality improvement and breeding projects in wine production. Main Conclusion: The active VvSS3, sucrose synthase (SS), and VvSWEET15 increases the hexose content in Petit Manseng berries, which are associated with sugar hydrolysis and transport.

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A cDNA encoding polygalacturonase-inhibiting protein (PGIP) from mature apple fruit has been cloned and characterized. The open reading frame encodes a polypeptide of 330 amino acids, in which 24 amino acids at the N-terminus comprise the signal peptide. Apple PGIP contains 10 imperfect leucine-rich repeat sequence motifs averaging 24 amino acids in length. In addition to the 1.3 kb PGIP transcript, the cloned cDNA also hybridized to RNA molecules with sizes of 3.2 and 5.0 kb. Genomic DNA analysis revealed that the apple PGIP probably belongs to a small family of genes. PGIP transcript levels varied in fruit collected at different maturities, suggesting the gene is developmentally regulated. Very high PGIP transcript levels were detected in decayed areas and the tissue adjacent to the inoculation sites of Penicillium expansum and Botrytis cinerea. However, no increase in the amount of PGIP transcript in tissue distant from the decayed region was observed. Wounding on fruit also induced PGIP gene expression but to a much lessser extent when compared with decayed areas. After storage at 0 degrees C for 1 month, the abundance of PGIP transcript in ripe fruit was substantially increased. The PGIP gene in immature and ripe fruit was rapidly up-regulated by fungal infections, while in stored fruit the induction was very limited and concurred with an increase of fruit susceptibility to fungal colonization. Since PGIP gene expression is regulated by fruit development and responds to wounding, fungal infection and cold storage, these observations suggest that apple PGIP may have multiple roles during fruit development and stress response.

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For better understanding the genetic diversity and phylogeny of the cultivated Salvia miltiorrhiza populations, four intergenic spacer sequences, ETS, psbA-trnH, trnL-trnF, and ycf1-rps15 of the 40 populations collected from China were Polymerase Chain Reaction (PCR) amplified, analyzed both individually and in combination. Haplotype diversity analysis showed that the cultivated S. miltiorrhiza populations had a very rich genetic diversity and an excellent capacity to resist environmental pressure. The best-fit nucleotide substitution models for ETS, psbA-trnH, trnL-trnF, ycf1-rps15, and their combined sequences were HKY+I, T92, T92, T92+G, and T92+G, respectively; the nucleotide conversion frequency in the combined sequences was lower than the transversion, and the relatively high nucleotide substitution frequencies suggests its high genetic variability. Neutral tests showed that the spacer sequences of the populations conform with the neutral evolution model, and there has been no current expansion events occurred. Phylogeny analyses based on both the individual and the combined sequences showed that the 40 populations were clustered in two clades with a very similar topological structure. The discrimination rate of the combined sequence marker is significantly increased to 52.5% (21 populations) over the highest 35% (13 populations) by the single marker of ETS, though still inadequate but a big step forward. Further exploration of more DNA markers is needed. This study for the first time revealed the rich genetic diversity and phylogeny of the currently cultivated S. miltiorrhiza populations in China and provides novel alternative molecular markers for the genetic identification and resources evaluation of the cultivated S. miltiorrhiza populations.