Sugar and abscisic acid signaling orthologs are activated at the onset of ripening in grape

Abstract

The onset of ripening involves changes in sugar metabolism, softening, and color development. Most understanding of this process arises from work in climacteric fruits where the control of ripening is predominately by ethylene. However, many fruits such as grape are nonclimacteric, where the onset of ripening results from the integration of multiple hormone signals including sugars and abscisic acid (ABA). In this study, we identified ten orthologous gene families in Vitis vinifera containing components of sugar and ABA-signaling pathways elucidated in model systems, including PP2C protein phosphatases, and WRKY and homeobox transcription factors. Gene expression was characterized in control- and deficit-irrigated, field-grown Cabernet Sauvignon. Sixty-seven orthologous genes were identified, and 38 of these were expressed in berries. Of the genes expressed in berries, 68% were differentially expressed across development and/or in response to water deficit. Orthologs of several families were induced at the onset of ripening, and induced earlier and to higher levels in response to water deficit; patterns of expression that correlate with sugar and ABA accumulation during ripening. Similar to field-grown berries, ripening phenomena were induced in immature berries when cultured with sucrose and ABA, as evidenced by changes in color, softening, and gene expression. Finally, exogenous sucrose and ABA regulated key orthologs in culture, similar to their regulation in the field. This study identifies novel candidates in the control of nonclimacteric fruit ripening and demonstrates that grape orthologs of key sugar and ABA-signaling components are regulated by sugar and ABA in fleshy fruit.Electronic supplementary materialThe online version of this article (doi:10.1007/s00425-010-1165-2) contains supplementary material, which is available to authorized users.

Genetic and Environmental Impacts on the Biosynthesis of Anthocyanins in Grapes

“…In studies by my research group, however, the expression patterns of VlMYBA1-2, VlMYBA1-3, and VlMYBA2 did not resemble the pattern of endogenous ABA levels (Azuma et al, 2012b). This suggests that the final anthocyanin content and the expression levels of related genes under natural conditions are determined by complex interactions among internal and external factors such as temperature, light, water status, sugar content, and endogenous ABA content Gambetta et al, 2010;Hiratsuka et al, 2001;Jeong et al, 2004;Kataoka et al, 1984Kataoka et al, , 2003Kliewer and Torres, 1972;Matus et al, 2009;Mori et al, 2007;Yamane et al, 2006). It also suggests that artificial ABA treatment can enhance the expression of MYB genes and of genes in the anthocyanin biosynthesis pathway.…”

Oxidative stress homeostasis in grapevine (Vitis vinifera L.)

“…In berries, the onset of ripening (veraison) when anthocyanin accumulation begins in red varieties, is accompanied by a marked increase in ABA concentration (Deluc et al, 2009;Gambetta et al, 2010) and correlates well with sugar accumulation (Gambetta et al, 2010). ABA has been shown to activate anthocyanin biosynthetic genes and the anthocyanin-synthesis related VvmybA1 transcription factor (Jeong et al, 2004), and to induce the delay of expression of proanthocyanidin biosynthetic genes (VvANR and VvLAR2) (Lacampagne et al, 2009).…”

The Basic Leucine Zipper Transcription Factor ABSCISIC ACID RESPONSE ELEMENT-BINDING FACTOR2 Is an Important Transcriptional Regulator of Abscisic Acid-Dependent Grape Berry Ripening Processes

“…Several studies have underlined the role of ABA in enhancing softening in both tomato (Zhang et al, 2009b) and grapevine (Gambetta et al, 2010). Indeed, it was suggested by Koyama et al (2010) that in grape berry, the modification of cell walls occurring under ABA treatment may be reflected by the differential transcript abundances of cell wall proteins and pectin-modifying enzymes.…”

“…ABA content of grape berries gradually and strongly increases just before the onset of ripening, called véraison (Coombe and Hale, 1973;Scienza et al, 1978;Davies et al, 1997;Antolín et al, 2003;Deluc et al, 2009). In relation with its accumulation profile, numerous reports suggested that ABA may play a major role in controlling several ripening-associated processes of grape berry, including coloration, sugar accumulation, and softening (Coombe, 1992;Davies et al, 1997;Giovannoni, 2001; Rodrigo et al, 2003;Yu et al, 2006;Wheeler et al, 2009;Gambetta et al, 2010;Giribaldi et al, 2010;Gagné et al, 2011).…”