Pectins, Hemicelluloses and Celluloses Show Specific Dynamics in the Internal and External Surfaces of Grape Berry Skin During Ripening.
Grapevine berry skin is a complex structure that contributes to the final size and shape of the fruit and affects its quality traits. The organization of cell wall polysaccharides in situ and their modification during ripening are largely uncharacterized. The polymer structure of Corvina berry skin, its evolution during ripening and related modifying genes were determined by combing mid-infrared micro-spectroscopy and multivariate statistical analysis with transcript profiling and immunohistochemistry. Spectra were acquired in situ using a surface-sensitive technique on internal and external sides of the skin without previous sample pre-treatment, allowing comparison of the related cell wall polymer dynamics. The external surface featured cuticle-related bands; the internal surface showed more adsorbed water. Application of surface-specific normalization revealed the major molecular changes related to hemicelluloses and pectins in the internal surface and to cellulose and pectins in the external surface and that they occur between mid-ripening and full ripening in both sides of the skin. Transcript profiling of cell wall-modifying genes indicated a general suppression of cell wall metabolism during ripening. Genes related to pectin metabolism-a β-galactosidase, a pectin(methyl)esterase and a pectate lyase-and a xyloglucan endotransglucosylase/hydrolase, involved in hemicellulose modification, showed enhanced expression. In agreement with Fourier transform infrared spectroscopy, patterns due to pectin methyl esterification provided new insights into the relationship between pectin modifications and the associated transcript profile during skin ripening. This study proposes an original description of polymer dynamics in grape berries during ripening, highlighting differences between the internal and external sides of the skin.
Department of Biotechnology, University of Verona, 37134 Verona, Italy These authors contributed equally to this work.
Marianna
M
Fasoli
Micro Nano Facility, Fondazione Bruno Kessler, 38123 Trento, Italy These authors contributed equally to this work.
Rossana
R
Dell'Anna
Department of Biotechnology, University of Verona, 37134 Verona, Italy.
Silvia
S
Dal Santo
Institute for Sustainable Plant Protection, CNR, 10125 Torino, Italy.
Raffaella
R
Balestrini
Department of Computer Science, University of Verona, 37134 Verona, Italy Present address: Department of Physics and Astronomy, University of Padova, 35131 Padova, Italy.
Andrea
A
Sanson
Department of Biotechnology, University of Verona, 37134 Verona, Italy.
Mario
M
Pezzotti
Department of Computer Science, University of Verona, 37134 Verona, Italy francesca.monti@univr.it.
Francesca
F
Monti
Department of Biotechnology, University of Verona, 37134 Verona, Italy.
Sara
S
Zenoni
D002473:Cell Wall / Q000235:genetics / Q000378:metabolism; D002482:Cellulose / Q000378:metabolism*; D005455:Fluorescent Antibody Technique; D005638:Fruit / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D005810:Multigene Family; D010368:Pectins / Q000378:metabolism*; D019441:Plant Epidermis / Q000235:genetics / Q000502:physiology; D011134:Polysaccharides / Q000378:metabolism*; D025341:Principal Component Analysis; D017550:Spectroscopy, Fourier Transform Infrared; D027843:Vitis / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D014867:Water / Q000378:metabolism
D011134:Polysaccharides; D014867:Water; C007916:hemicellulose; D010368:Pectins; D002482:Cellulose
Berry skin ripening; Cell wall; Mid-infrared FTIR micro-spectroscopy; Multivariate data analysis; Pectin methyl esterification; Transcript profiling