This view shows enzymes only for those organisms listed below, in the list of taxa known to possess the pathway. If an enzyme name is shown in bold, there is experimental evidence for this enzymatic activity.
Synonyms: ethylene-stimulated fruit ester biosynthesis
|Superclasses:||Biosynthesis → Secondary Metabolites Biosynthesis → Phenylpropanoid Derivatives Biosynthesis|
Expected Taxonomic Range: Viridiplantae
The plant hormone ethylene plays an important role in the fruit ripening stages of climacteric fruits. It triggers the formation of complex sets of flavor and aroma volatiles at specific stages of fruit ripening [Whittaker97a]. In kiwi fruits, volatile esters are formed by the action of acyltransferases belonging to BAHD (benzyl alcohol-acetyl-, anthocyanin-O-hydroxy-cinnamoyl-, anthranilate-N-hydroxycinnamoyl/benzoyl-, deacetyl-vindoline) superfamily. The BAHD proteins use Coenzyme A (CoA)-thioesters as acyl donors, and one sub group of alcohol acyltransferases produce volatile esters that are associated with fruity aroma. The alcohol acylation of ripening specific acyltransferases was molecularly analyzed [Gunther11].
The fruit ester profiles of the kiwifruit cultivars reach peak levels at the soft end of their eating firmness stage [Whittaker97a]. Methylsulfanyl alkanoate and benzoate esters are part of the volatile profiles of kiwifruit [Gunther10]. ethanol is the major alcohol detected in kiwi cultivars and nearly 50% of volatile esters are ethyl esters.
About this pathway The changes of volatile profiles in response to ethylene is well researched, and the above pathway documents the volatile ester formation during specific fruit ripening stages. The substrate preferences of the alcohol acyltransferase (AAT) was analyzed and found to be variable in the AAT transcripts of kiwifruit. AT16 possessed benzoyl-CoA:alcohol O-acyltransferase activity and AT9 has an acetyl-CoA:alcohol O-acyltransferase activity. Although ethanol is the main alcohol in ripe kiwifruit, AT16 and AT9 were more reactive with n-butanol as compared to ethanol [Gunther11].
Gunther10: Gunther CS, Matich AJ, Marsh KB, Nicolau L (2010). "(Methylsulfanyl)alkanoate ester biosynthesis in Actinidia chinensis kiwifruit and changes during cold storage." Phytochemistry 71(7);742-50. PMID: 20189207
Gunther11: Gunther CS, Chervin C, Marsh KB, Newcomb RD, Souleyre EJ (2011). "Characterisation of two alcohol acyltransferases from kiwifruit (Actinidia spp.) reveals distinct substrate preferences." Phytochemistry 72(8);700-10. PMID: 21450321
Boatright04: Boatright J, Negre F, Chen X, Kish CM, Wood B, Peel G, Orlova I, Gang D, Rhodes D, Dudareva N (2004). "Understanding in vivo benzenoid metabolism in petunia petal tissue." Plant Physiol 135(4);1993-2011. PMID: 15286288
DAuria02: D'Auria JC, Chen F, Pichersky E (2002). "Characterization of an acyltransferase capable of synthesizing benzylbenzoate and other volatile esters in flowers and damaged leaves of Clarkia breweri." Plant Physiol 130(1);466-76. PMID: 12226525
Dudareva98a: Dudareva N, Raguso RA, Wang J, Ross JR, Pichersky E (1998). "Floral scent production in Clarkia breweri. III. Enzymatic synthesis and emission of benzenoid esters." Plant Physiol 116(2);599-604. PMID: 9489012
Orlova06: Orlova I, Marshall-Colon A, Schnepp J, Wood B, Varbanova M, Fridman E, Blakeslee JJ, Peer WA, Murphy AS, Rhodes D, Pichersky E, Dudareva N (2006). "Reduction of benzenoid synthesis in petunia flowers reveals multiple pathways to benzoic acid and enhancement in auxin transport." Plant Cell 18(12);3458-75. PMID: 17194766
Rubio06: Rubio S, Larson TR, Gonzalez-Guzman M, Alejandro S, Graham IA, Serrano R, Rodriguez PL (2006). "An Arabidopsis mutant impaired in coenzyme A biosynthesis is sugar dependent for seedling establishment." Plant Physiol 140(3);830-43. PMID: 16415216
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