A RhABF2/Ferritin module affects rose (Rosa hybrida) petal dehydration tolerance and senescence by modulating iron levels

Abstract

Plants often develop the capacity to tolerate moderate and reversible environmental stresses, such as drought, and to re-establish normal development once the stress has been removed. An example of this phenomenon is provided by cut rose (Rosa hybrida) flowers, which experience typical reversible dehydration stresses during post-harvest handling after harvesting at the bud stages. The molecular mechanisms involved in rose flower dehydration tolerance are not known, however. Here, we characterized a dehydration- and abscisic acid (ABA)-induced ferritin gene (RhFer1). Dehydration-induced free ferrous iron (Fe ) is preferentially sequestered by RhFer1 and not transported outside of the petal cells, to restrict oxidative stresses during dehydration. Free Fe accumulation resulted in more serious oxidative stresses and the induction of genes encoding antioxidant enzyme in RhFer1-silenced petals, and poorer dehydration tolerance was observed compared with tobacco rattle virus (TRV) controls. We also determined that RhABF2, an AREB/ABF transcription factor involved in the ABA signaling pathway, can activate RhFer1 expression by directly binding to its promoter. The silencing of RhABF2 decreased dehydration tolerance and disrupted Fe homeostasis in rose petals during dehydration, as did the silencing of RhFer1. Although both RhFer1 and Fe transporter genes are induced during flower natural senescence in plants, the silencing of RhABF2 or RhFer1 accelerates the petal senescence processes. These results suggest that the regulatory module RhABF2/RhFer1 contributes to the maintenance of Fe levels and enhances dehydration tolerance through the action of RhFer1 locally sequestering free Fe under dehydration conditions, and plays synergistic roles with transporter genes during flower senescence.

RhMYB108, an R2R3-MYB transcription factor, is involved in ethylene- and JA-induced petal senescence in rose plants

“…The function of ethylene and JA in the acceleration of leaf senescence has been widely reported 21,25 , but the interaction and crosstalk between these hormones during flower senescence has not been studied in detail. To determine the effects of ethylene and JA during flower senescence, we introduced a rose petal disc system 13,43 . As shown in Fig.…”

Proteome and Ubiquitome Changes during Rose Petal Senescence

“…In petunia, potassium and phosphorus contents decrease [77,78], and transcripts of a phosphate transporter, PhPT, accumulate in senescing corollas [78]. Expression of Fe transporter genes is induced in senescing rose petals [79]. Moreover, many transporters related to petal senescence were identified via transcriptome approaches in plant species, such as alstroemeria, carnation, and iris [15,16,56].…”

Overexpression of GhABF3 increases cotton(Gossypium hirsutum L.) tolerance to salt and drought

“…Heterologous expression of DcABF3 altered stomatal density and reduced ABA sensitivity and improved drought resistance in Arabidopsis [26]. The silencing of RhABF2 reduced rose (Rosa hybrid) dehydration tolerance and disrupted Fe homeostasis in rose petals during dehydration [27]. High salt concentration inhibited the expression of GhABF2 in cotton, but the salt tolerance of cotton overexpressing GhABF2 was improved [21].…”