Transcriptome profiling of postharvest strawberry fruit in response to exogenous auxin and abscisic acid

Abstract

Auxin and abscisic acid regulate strawberry fruit ripening and senescence through cross-talk of their signal transduction pathways that further modulate the structural genes related to physico-chemical properties of fruit. The physiological and transcriptomic changes in harvested strawberry fruits in responses to IAA, ABA and their combination were analyzed. Exogenous IAA delayed the ripening process of strawberries after harvest while ABA promoted the postharvest ripening. However, treatment with a combination of IAA and ABA did not slow down nor accelerate the postharvest ripening in the strawberry fruits. At the molecular level, exogenous IAA up regulated the expressions of genes related to IAA signaling, including AUX/IAA, ARF, TOPLESS and genes encoding E3 ubiquitin protein ligase and annexin, and down regulated genes related to pectin depolymerization, cell wall degradation, sucrose and anthocyanin biosyntheses. In contrast, exogenous ABA induced genes related to fruit softening, and genes involved in signaling pathways including SKP1, HSPs, CK2, and SRG1. Comparison of transcriptomes in responses to individual treatments with IAA or ABA or the combination revealed that there were cooperative and antagonistic actions between IAA and ABA in fruit. However, 17% of the differentially expressed unigenes in response to the combination of IAA and ABA were unique and were not found in those unigenes responding to either IAA or ABA alone. The analyses also found that receptor-like kinases and ubiquitin ligases responded to both IAA and ABA, which seemed to play a pivotal role in both hormones' signaling pathways and thus might be the cross-talk points of both hormones.

Abscisic Acid Regulates Anthocyanin Biosynthesis and Gene Expression Associated With Cell Wall Modification in Ripening Bilberry (Vaccinium myrtillus L.) Fruits

“…Earlier, fruit softening related gene expression has been studied extensively in strawberry having also a short shelf life. Indications that ABA activates expression of FaPL, FaCEL, FaRGlyase, FcXTH1, Fa β Gal4, FaXYL1 and expansins have been reported (Bustamante et al, 2009; Molina-Hidalgo et al, 2013; Opazo et al, 2013; Chen et al, 2016; Medina-Puche et al, 2016; Paniagua et al, 2016). However, earlier studies have shown that the textural changes occurring during fruit ripening are characteristic to particular fruit species, and are due to differences in type and extent of cell wall modifications and the expression of the modifying enzymes during ripening (Goulao and Oliveira, 2008; Payasi et al, 2009).…”

“…Exogenous application of ABA has been shown in many studies to advance especially non-climacteric fruit ripening and the associated anthocyanin accumulation in grape berries (Wheeler et al, 2009; Koyama et al, 2010; Villalobos-González et al, 2016), strawberries (Chai et al, 2011; Jia et al, 2011; Kadomura-Ishikawa et al, 2015; Chen et al, 2016), sweet cherries (Luo et al, 2014; Shen et al, 2014), and litchi fruit (Wei et al, 2011; Singh et al, 2014). Moreover, treatments with inhibitors of ABA biosynthesis, such as fluridone and nordihydroguaiaretic acid (NDGA), delay fruit ripening and decrease anthocyanin accumulation (Jia et al, 2011; Shen et al, 2014; Kadomura-Ishikawa et al, 2015).…”

“…Earlier, similar results have been reported and externally applied ABA has been found to elevate NCED gene expression and ABA synthesis in grapes (Wheeler et al, 2009), cucumber (Wang et al, 2013), and sweet cherry (Luo et al, 2014). Up-regulation of FaNCED1 expression by ABA has also been demonstrated in strawberry fruits (Chen et al, 2016; Medina-Puche et al, 2016) and it was suggested that the autocatalytic biosynthesis of ABA may be necessary for the induction of high increase in ABA production at fruit ripening (Medina-Puche et al, 2016). …”

Comparative Transcriptome Analysis Reveals Effects of Exogenous Hematin on Anthocyanin Biosynthesis during Strawberry Fruit Ripening

“…It has shown that auxin suppresses anthocyanin biosynthesis in the red-fleshed apple callus [43]. Endogenous expression of auxin [44, 45] has been found to impede anthocyanin accumulation in strawberries. In additional, cytokinins are also known to play an important role in anthocyanin biosynthesis.…”

Genome-wide analysis and characterization of Aux/IAA family genes related to fruit ripening in papaya (Carica papaya L.)

“…Fruit ripening is associated with auxin signaling involved in the postharvest storage of fruits [28]. The elucidation of how AUX/IAA-mediated auxin signaling function in postharvest decay is therefore of importance to both plant biologists and agronomists [29]. In the present work, we provide comprehensive information on the genomic structures, sequence homology levels and expression patterns of Aux/IAA genes in papaya.…”