Ethylene-responsive transcription factors interact with promoters of ADH and PDC involved in persimmon (Diospyros kaki) fruit de-astringency

Abstract

The persimmon fruit is a particularly good model for studying fruit response to hypoxia, in particular, the hypoxia-response ERF (HRE) genes. An anaerobic environment reduces fruit astringency by converting soluble condensed tannins (SCTs) into an insoluble form. Although the physiology of de-astringency has been widely studied, its molecular control is poorly understood. Both CO2 and ethylene treatments efficiently removed the astringency from ‘Mopan’ persimmon fruit, as indicated by a decrease in SCTs. Acetaldehyde, the putative agent for causing de-astringency, accumulated during these treatments, as did activities of the key enzymes of acetaldehyde synthesis, alcohol dehydrogenase (ADH), and pyruvate decarboxylase (PDC). Eight DkADH and DkPDC genes were isolated, and three candidates for a role in de-astringency, DkADH1, DkPDC1, and DkPDC2, were characterized by transcriptional analysis in different tissues. The significance of these specific isoforms was confirmed by principal component analysis. Transient expression in leaf tissue showed that DkPDC2 decreased SCTs. Interactions of six hypoxia-responsive ERF genes and target promoters were tested in transient assays. The results indicated that two hypoxia-responsive ERF genes, DkERF9 and DkERF10, were involved in separately regulating the DkPDC2 and DkADH1 promoters. It is proposed that a DkERF–DkADH/DkPDC cascade is involved in regulating persimmon de-astringency.

Two Novel Anoxia-Induced Ethylene Response Factors That Interact with Promoters of Deastringency-Related Genes from Persimmon

“…Transient overexpression of DkPDC2 in persimmon leaves resulted in lower SCTs content [12]. In addition, several hypoxia-responsive ERF transcriptional regulator genes were also isolated, including DkERF4 , DkERF5 , DkERF9 and DkERF10 [12], [13], but only DkERF9 and DkERF10 activated the promoters of DkPDC2 and DkADH1 , respectively [12]. These results suggested that ERF genes are involved in transcriptional regulation of persimmon fruit deastringency, and also expanded the functional changes involving ERF genes, which also include texture [14]–[16], carotenoids [17], ethylene [18], senescence [19] and stress response [20].…”

“…Transient overexpression of DkPDC2 in persimmon leaves resulted in lower SCTs content [12]. In addition, several hypoxia-responsive ERF transcriptional regulator genes were also isolated, including DkERF4 , DkERF5 , DkERF9 and DkERF10 [12], [13], but only DkERF9 and DkERF10 activated the promoters of DkPDC2 and DkADH1 , respectively [12].…”

Hypoxia‐responsive ERFs involved in postdeastringency softening of persimmon fruit

“…Plant responses to anoxia involve a range of metabolic and morphological changes on different timescales, including rapid induction of anaerobic metabolism (Kennedy et al ., ; Voesenek and Bailey‐Serres, ). For persimmon ( Diospyros kaki ), the anaerobic metabolite acetaldehyde, which accumulates under high CO 2 treatment (95%), participates in fruit postharvest deastringency by converting the soluble tannins to insoluble products (Min et al ., ; Pesis and Ben‐Arie, ; Taira et al ., , ). However, deastringency is usually also accompanied by rapid fruit softening (Arnal and Del Río, ; Yin et al ., ).…”

Development of Agrobacterium-mediated transient transformation in persimmon (Diospyros kaki Thunb.)

“…By comparison, on account of some superior characteristics such as simplicity, easy performance and cost saving, the Agrobacterium-mediated transient gene expression system has been wildly used for characterization of genes function in herb and woody plants (Li et al, 2009;Wydro et al, 2006;Orzaez et al, 2006;Figueiredo et al, 2011). So far, only one study has reported that a transient expression system according to the protocols used for tobacco was applied in persimmon (Min et al, 2012). However, to our knowledge, no system of transient gene expression for persimmon has been specially established.…”