Leaf:fruit Ratio Affects the Proteomic Profile of Grape Berry Skins

Abstract

<jats:p>The most obvious effects of a low leaf:fruit (LF) ratio [two leaves for one cluster per shoot (LF2)] on grape (<jats:italic>Vitis vinifera</jats:italic>) berries are suppressed anthocyanin biosynthesis in the berry skin, decreased berry weight and soluble solids concentration, and increased titratable acidity. In this study, proteins isolated from berry skins grown under low and high LF ratio conditions, LF2 and LF12, respectively, were characterized by two-dimensional gel electrophoresis coupled to mass spectrometry. A survey of ≈600 to 700 spots from berry skin yielded 77 proteins with differential expression between LF12 and LF2 treatments. Of these, the 59 proteins that were identified consisted of 47 proteins that were down-regulated and 12 that were up-regulated under LF2 conditions compared with LF12 conditions. Most proteins involved in metabolism, energy, transcription, protein synthesis, binding function, signal transduction, and cell defense were down-regulated in LF2 berries, whereas two important enzymes of anthocyanin biosynthesis, chalcone synthase and dihydroflavonol reductase, were not detected. Only a few proteins (e.g., two heat shock proteins related to protein fate and nutrient reservoir storage protein) were found to be up-regulated in LF2 berries. This suggested that, with the exception of secondary metabolism, many proteomic events may have an effect on anthocyanin synthesis in the skins responding to LF.</jats:p>

Effects of Natural Hail on the Growth, Physiological Characteristics, Yield, and Quality of Vitis vinifera L. cv. Thompson Seedless under Mediterranean Growing Conditions

“…Abiotic constraints are known to exert a negative effect on secondary metabolites, such as phenolic compounds [51]. Also, in our study, a competitive relationship between primary and secondary metabolites in berries was registered (Table 3), confirming other results reported previously [52,53]. In HD berries, the impact of natural hail might have inhibited phenolic biosynthesis and/or promoted phenolic degradation.…”

Differential responses of sugar, organic acids and anthocyanins to source-sink modulation in Cabernet Sauvignon and Sangiovese grapevines

“…After recalculation from the dataset of recent reports, we found that source limitation caused a 99.2% reduction in anthocyanins with a 38.5% reduction in sugars in cv. Jingyan ( Vitis vinifera ; Wu et al, 2013 ), and a 17.5 or 19.1% reduction in anthocyanins with a 8.4 or 6.8% reduction in sugars in cv. Sangiovese ( Pastore et al, 2011 , 2013 ).…”

“…Two recent genome-wide transcriptome analyses showed that carbon limitation reduced the transcript abundance of UDP glucose:flavonoid-3- O -glucosyltransferase (UFGT) and GST4, which are known as important regulators of anthocyanin accumulation and transport ( Pastore et al, 2011 , 2013 ). A proteomic analysis showed that the abundances of chalcone synthase and dihydroflavonol reductase, which are both involved in anthocyanin pathway, were strongly reduced by source limitation ( Wu et al, 2013 ). Our observed reduction in total anthocyanin in both cultivars under source limitation should also result from modifications in the key regulators of anthocyanin pathways, although further transcriptomic and proteomic experiments are needed to confirm these speculations.…”

“…Above this value, the sugar concentration usually reaches a plateau and becomes less responsive to source-sink modulation ( Kliewer and Dokoozlian, 2005 ). The responses of organic acids to source-sink modulation have been less thoroughly studied, and contradictory reports showed that a lower leaf area-to-yield ratio caused either an increase ( Wolpert et al, 1983 ; Ollat and Gaudillere, 1998 ; Wu et al, 2013 ), decline ( Bravdo et al, 1985 ), or lack of response ( Reynolds et al, 1994 ; Parker et al, 2015 ) of organic acids compared with a high leaf to yield ratio.…”

“…Source-sink modulation impacts berry coloration ( Weaver, 1963 ; Kliewer and Weaver, 1971 ; Petrie et al, 2000a ), and recently its effects on anthocyanin content and composition ( Guidoni et al, 2008 ; Pastore et al, 2011 , 2013 ; Filippetti et al, 2015 ) drew attention of many research groups. For example, Wu et al (2013) showed that retaining two leaves only in a girdled shoot with one cluster completely inhibited berry coloration. Moreover, Guidoni et al (2008) reported that total anthocyanins were reduced by source limitation, with di-hydroxylated anthocyanins more sensitive than tri-hydroxylated ones in cv.…”