Proteomic analysis reveals dynamic regulation of fruit development and sugar and acid accumulation in apple.

Understanding the fruit developmental process is critical for fruit quality improvement. Here, we report a comprehensive proteomic analysis of apple fruit development over five growth stages, from young fruit to maturity, coupled with metabolomic profiling. A tandem mass tag (TMT)-based comparative proteomics approach led to the identification and quantification of 7098 and 6247 proteins, respectively.

[Vesicular transport protein VdSec22 is involved in secretion of extracellular protein and pathogenicity in Verticillium dahliae].

Objective: The aim of this study was to characterize VdSec22 of Verticillium dahliae, which is an intracellular vesicle fusion protein involved in fungal secretory pathway, and to provide a potential gene target for controlling Verticillium wilt disease.

Methods: VdSec22 deletion mutant ΔQF and functional complementation strain CΔQF by reintroducing the VdSec22 intoAQF were constructed. Secretion ability of extracellular protein (including pectinase, cellulose, and phytotoxin protin) and pathogenicity of ΔQF and CΔQF were studied compared with that of wild type strain Vd991.

Effects of location within the tree canopy on carbohydrates, organic acids, amino acids and phenolic compounds in the fruit peel and flesh from three apple (Malus × domestica) cultivars.

Fruits from three cultivars of apple (Malus × domestica Borkh.)-'McIntosh', 'Gala' and 'Mutsu'-were harvested from the exterior and interior of the tree canopy. Peel and flesh tissues were sampled separately to determine how the position of the fruit on the tree might affect the levels of the primary and secondary metabolites in the fruit.

Delay in leaf senescence of Malus hupehensis by long-term melatonin application is associated with its regulation of metabolic status and protein degradation.

Melatonin has an important anti-aging role in plant physiology. We tested the effects of long-term melatonin exposure on metabolic status and protein degradation during natural leaf senescence in trees of Malus hupehensis Rehd. The 2-month regular supplement of 100 μm melatonin to the soil once every 6 days altered the metabolic status and delayed protein degradation.

Phenylpropanoid metabolites and expression of key genes involved in anthocyanin biosynthesis in the shaded peel of apple fruit in response to sun exposure.

The shaded peel of 'Fortune' (a red cultivar) and 'Mutsu' (a yellow/green cultivar) apple (Malus domestica Borkh.) was exposed to full sun by turning fruit 180° at about one week before harvest to determine the expression of key genes involved in anthocyanin synthesis in response to sunlight exposure and their relationships with the levels of anthocyanins and other phenolics. For the unturned (control) fruit, the shaded peel had lower expression levels of MdMYB10 (a transcriptional factor in the regulation of anthocyanin biosynthesis) and seven structural genes in anthocyanin synthesis (MdPAL, MdCHS, MdCHI, MdF3H, MdDFR1, MdLDOX, and MdUFGT), and lower levels of anthocyanins and flavonols than the sun-exposed peel in both cultivars.

Expression patterns of genes involved in sugar metabolism and accumulation during apple fruit development.

Both sorbitol and sucrose are imported into apple fruit from leaves. The metabolism of sorbitol and sucrose fuels fruit growth and development, and accumulation of sugars in fruit is central to the edible quality of apple. However, our understanding of the mechanisms controlling sugar metabolism and accumulation in apple remains quite limited.