TY - JOUR
T1 - Concealed ester formation and amino acid metabolism to volatile compounds in table grape (Vitis vinifera L.) berries
AU - Maoz, Itay
AU - Rikanati, Rachel Davidovich
AU - Schlesinger, Daniel
AU - Bar, Einat
AU - Gonda, Itay
AU - Levin, Elena
AU - Kaplunov, Tatiana
AU - Sela, Noa
AU - Lichter, Amnon
AU - Lewinsohn, Efraim
N1 - Publisher Copyright:
© 2018
PY - 2018/9
Y1 - 2018/9
N2 - Volatile esters contribute to the aroma and flavor of many fruits but are normally absent in grape berries (Vitis vinifera L.). To examine the biosynthetic potential of grape berries to form volatile esters, berry sections were incubated with exogenous L-Phe, L-Leu or L-Met. In general, amino-acid incubation caused the accumulation of the respective aldehydes and alcohols. Moreover, L-Leu incubation resulted in the accumulation of 3-methylbutyl acetate and L-Phe incubation resulted in the accumulation 2-phenylethyl acetate in ‘Muscat Hamburg’ but not in the other grape accessions. Exogenous L-Met administration did not result in volatile esters accumulation but the accumulation of sulfur volatile compounds such as methional and dimethyl disulfide was prominent. Berry-derived cell-free extracts displayed differential alcohol acetyltransferase activities and supported the formation of 3-methylbutyl acetate and benzyl acetate. 2-Phenylethyl acetate was produced only in ‘Muscat Hamburg’ cell-free extracts. VvAAT2, a newly characterized gene, was preferentially expressed in ‘Muscat Hamburg’ berries and functionally expressed in E. coli. VvAAT2 possesses alcohol acetyltransferase activity utilizing benzyl alcohol, 2-phenylethanol, hexanol or 3-methylbutanol as substrates. Our study demonstrates that grape berries have a concealed potential to accumulate volatile esters and this process is limited by substrate availability.
AB - Volatile esters contribute to the aroma and flavor of many fruits but are normally absent in grape berries (Vitis vinifera L.). To examine the biosynthetic potential of grape berries to form volatile esters, berry sections were incubated with exogenous L-Phe, L-Leu or L-Met. In general, amino-acid incubation caused the accumulation of the respective aldehydes and alcohols. Moreover, L-Leu incubation resulted in the accumulation of 3-methylbutyl acetate and L-Phe incubation resulted in the accumulation 2-phenylethyl acetate in ‘Muscat Hamburg’ but not in the other grape accessions. Exogenous L-Met administration did not result in volatile esters accumulation but the accumulation of sulfur volatile compounds such as methional and dimethyl disulfide was prominent. Berry-derived cell-free extracts displayed differential alcohol acetyltransferase activities and supported the formation of 3-methylbutyl acetate and benzyl acetate. 2-Phenylethyl acetate was produced only in ‘Muscat Hamburg’ cell-free extracts. VvAAT2, a newly characterized gene, was preferentially expressed in ‘Muscat Hamburg’ berries and functionally expressed in E. coli. VvAAT2 possesses alcohol acetyltransferase activity utilizing benzyl alcohol, 2-phenylethanol, hexanol or 3-methylbutanol as substrates. Our study demonstrates that grape berries have a concealed potential to accumulate volatile esters and this process is limited by substrate availability.
KW - Acetyl esters
KW - Alcohol acetyltransferase
KW - Amino acids
KW - Enzyme activity
KW - Functional expression VvAAT2
UR - http://www.scopus.com/inward/record.url?scp=85047838328&partnerID=8YFLogxK
U2 - 10.1016/j.plantsci.2018.05.020
DO - 10.1016/j.plantsci.2018.05.020
M3 - Article
C2 - 30080607
AN - SCOPUS:85047838328
SN - 0168-9452
VL - 274
SP - 223
EP - 230
JO - Plant Science
JF - Plant Science
ER -