Silencing of the phytoene desaturase () gene affects the expression of fruit-ripening genes in tomatoes.

Background: Past research has shown that virus-induced phytoene desaturase () gene silencing via agroinjection in the attached and detached fruit of tomato plants results in a pale-yellow fruit phenotype. Although the gene is often used as a marker for gene silencing in tomatoes, little is known about the role of in fruit ripening. In this study, we investigated whether the pepper gene silenced endogenous genes in the fruit of two tomato cultivars, Dotaerang Plus and Legend Summer.

Results: We found that the pepper gene successfully silenced endogenous in tomato fruit at a silencing frequency of 100% for both cultivars. A pale-yellow silenced area was observed over virtually the entire surface of individual fruit due to the transcriptional reduction in phytoene desaturase (), zeta-carotene (), prolycopene isomerase (), and beta-carotene hydroxylase (-), which are the carotenoid biosynthesis genes responsible for the red coloration in tomatoes. silencing also affected the expression levels of the fruit-ripening genes Tomato AGAMOUS-LIKE1 (), RIPENING INHIBITOR (), pectin esterase gene (), lipoxygenase (), FRUITFULL1/FRUITFUL2 (), and the ethylene biosynthesis and response genes 1-aminocyclopropane-1-carboxylate oxidase 1 and 3 ( and ) and ethylene-responsive genes ( and ).

Conclusion: These results suggest that is a positive regulator of ripening in tomato fruit, which must be considered when using it as a marker for virus-induced gene silencing (VIGS) experiments in order to avoid fruit-ripening side effects.