Exogenous ethylene stimulates the long‐term expression of genes related to anthocyanin biosynthesis in grape berries

Abstract

The treatment of grape berries (Vitis vinifera L. cv. Cabernet Sauvignon) with the ethylene-releasing compound, 2-chloroethylphosphonic acid (2-CEPA), at veraison is a method known to enhance grape skin colour. We observed that it produced a 6-fold increase, up to 30 pmol g À1 FW, of the cluster internal ethylene compared to untreated controls within the 24 h following treatment. This ethylene upsurge was associated with increased levels of chalcone synthase (CHS) and flavanone 3-hydroxylase (F3H) transcripts, which persisted over the following 20 days. Transcript levels of leucoanthocyanidin dioxygenase (LDOX) and UDP glucose-flavonoid 3-O-glucosyl transferase (UFGT) were similarly enhanced by 2-CEPA, although to a lesser extent. The effect on UFGT was confirmed at the protein level by an immunoblot analysis. The transcript accumulation of dihydro-flavonol 4-reductase (DFR) was unaffected by 2-CEPA treatment. Examination of the levels of CHS, F3H and UFGT mRNAs in berries during bunch exposure to ethylene, revealed elevated levels of each transcript within the first 6 h of treatment when compared to nonethylene-treated controls. HPLC analyses of berry skin extracts showed that levels of each of the anthocyanins analysed (delphinidin, cyanidin, petunidin, peonidin and malvidin) increased over the 10 days following the ethylene burst, and decreased thereafter. However, anthocyanin levels at harvest were still higher in ethylene treated grapes than in controls. This data is the first evidence that ethylene triggers gene expression related to anthocyanin synthesis in grapes, and in addition, our results also confirm the existence of other regulatory modes in the anthocyanin biosynthetic pathway.

Sugar-Hormone Cross-Talk in Anthocyanin Biosynthesis

“…Treatment of grape berries with the ethylene-releasing compound 2-chloroethylphosphonic acid activated the transcription of structural genes encoding the key enzymes of anthocyanin biosynthesis and increased anthocyanin accumulation (El-Kereamy et al, 2003). Ethylene also plays a negative regulatory role in anthocyanin biosynthesis.…”

Brassinosteroids Regulate Anthocyanin Biosynthesis in the Ripening of Grape Berries

“…All of these things have a dual outcome: on the one hand, various environmental factors cause poor coloration in some areas (Mori et al, 2005), even for the same cultivars planted in different grape production areas; and on the other hand, these environmental stimuli can be used to improve the grape coloration. There have been many kinds of classical plant hormones applied to grapes to improve coloration, such as ethylene, naphthalene acetic acid, and abscisic acid, and these have also been implicated in the control of ripening of grape berries (Ban et al, 2003;El-kereamy et al, 2003;Jeong et al, 2004;Quiroga et al, 2009)…”

Ethylene pre-harvest application in ‘Cabernet Sauvignon’ produced in the region of “Dom Pedrito” – RS

“…The use of ethylene-releasing compounds to enhance grape colour is one of the main practices in the vineyard [9].…”