Genome-wide DNA methylation dynamics and RNA-seq analysis during grape (cv. 'Cabernet Franc') skin coloration.

This study generated whole genome DNA methylation maps to characterize DNA methylomes of grape (cv. 'Cabernet Franc') skins and examine their functional significance during grape skin coloration. We sampled grape skin tissues at three key stages (the early stage of grape berry swelling, the late stage of grape berry swelling and the veraison) during which the color of grape berries changed from green to red. DNA methylation levels of grape skins at the three stages were higher in transposable element regions than in the genic regions, and the CG and CHG DNA methylation levels of the genic region were higher than the CHH DNA methylation levels. We identified differentially methylated regions (DMRs) in S2_vs_S1 and S3_vs_S1. The results indicated that DMRs predominantly occurred within the CHH context during grape skin coloration. Many gene ontology (GO)-enriched DMR-related genes were involved in "nucleotide binding," "catalytic activity" and "ribonucleotide binding" terms; however, many KEGG-enriched DMR-related genes were involved in the "flavonoid biosynthesis" pathway. Our results could provide an important foundation for future research on the development mechanism of grape berries.

[Effects of foliar spraying DA-6 on the photosynthetic rate and plant growth of strawberry in autumn].

With strawberry ' French 3' (Fragaria x ananassa Duch cv. French 3) as test material, this paper studied the effects of foliar spraying DA-6 at the rates of 10, 20 and 30 mg x L(-1) in late autumn on its seedlings net photosynthetic rate, metabolism of reactive oxygen species, and plant growth. Compared with the control, foliar spraying DA-6 of 20 and 30 mg x L(-1) increased the net photosynthetic rate, chlorophyll a and b contents, and SOD and CAT activities significantly, and decreased the reactive oxygen and MDA contents. Moreover, foliar spraying DA-6 of 20 and 30 mg x L(-1) increased the average dry weight per leaf, and the dry mass of shoot and root significantly. The ratio of root to shoot after spraying DA-6 of 20 and 30 mg x L(-1) was 29.9% and 29.3% higher than the control, respectively. Foliar spraying appropriate concentration of DA-6 in late autumn could improve the plant growth of strawberry seedlings.