Overexpression of PgCBF3 and PgCBF7 Transcription Factors from Pomegranate Enhances Freezing Tolerance in Arabidopsis under the Promoter Activity Positively Regulated by PgICE1

Abstract

Cold stress limits plant growth, development and yields, and the C-repeat binding factors (CBFs) function in the cold resistance in plants. However, how pomegranate CBF transcription factors respond to cold signal remains unclear. Considering the significantly up-regulated expression of PgCBF3 and PgCBF7 in cold-tolerant Punica granatum ‘Yudazi’ in comparison with cold-sensitive ‘Tunisia’ under 4 °C, the present study focused on the two CBF genes. PgCBF3 was localized in the nucleus, while PgCBF7 was localized in the cell membrane, cytoplasm, and nucleus, both owning transcriptional activation activity in yeast. Yeast one-hybrid and dual-luciferase reporter assay further confirmed that PgICE1 could specifically bind to and significantly enhance the activation activity of the promoters of PgCBF3 and PgCBF7. Compared with the wild-type plants, the PgCBF3 and PgCBF7 transgenic Arabidopsis thaliana lines had the higher survival rate after cold treatment; exhibited increased the contents of soluble sugar and proline, while lower electrolyte leakage, malondialdehyde content, and reactive oxygen species production, accompanying with elevated enzyme activity of catalase, peroxidase, and superoxide dismutase; and upregulated the expression of AtCOR15A, AtCOR47, AtRD29A, and AtKIN1. Collectively, PgCBFs were positively regulated by the upstream PgICE1 and mediated the downstream COR genes expression, thereby enhancing freezing tolerance.

A Genome-Wide Analysis of the BAM Gene Family and Identification of the Cold-Responsive Genes in Pomegranate (Punica granatum L.)

“…In plants, β-amylase primarily catalyzes the hydrolysis of starch. The availability of extensive genomic data from various species has greatly facilitated the identification of Additionally, the expression of PgCBF7 (LOC116202526), a known transcription factor crucial for pomegranate's cold response [25,31], was also detected. Despite differences in cold stress tolerance, PgCBF7 was significantly upregulated under LT in both 'Tunisia' and 'Sanbai' cultivars (Figure 9D), confirming its pivotal role in regulating cold responses.…”

“…Additionally, the expression of PgCBF7 (LOC116202526), a known transcription factor crucial for pomegranate's cold response [25,31], was also detected. Despite differences in cold stress tolerance, PgCBF7 was significantly upregulated under LT in both 'Tunisia' and 'Sanbai' cultivars (Figure 9D), confirming its pivotal role in regulating cold responses.…”

“…Cold temperatures below 3 • C can inflict damage on buds and new shoots, while temperatures descending below 10 • C hinder plant growth and development [24]. To date, several genes associated with cold stress tolerance in pomegranates have been characterized, including PgICE1, PgCBF3, and PgCBF7 [25]. An RNA-seq analysis has uncovered that pathways related to starch and sucrose metabolism are significantly enriched in the response to cold and freezing stress of 'Tunisia' [24].…”

Silencing a dehydration‐responsive element‐binding gene enhances the resistance of plants to a phloem‐feeding herbivore

“…JA, ethylene and ABA signalling pathways regulate the biosynthesis of many defensive compounds, such as terpenoids and phenolics (Divekar et al, 2022; Erb & Reymond, 2019; He et al, 2022; Wari et al, 2022). Moreover, a number of DREB/CBFs, including OsDREB1A, are known to promote plants' resistance to cold by increasing the content of amino acids and soluble sugars (Feng et al, 2019; Ito et al, 2006; Lata & Prasad, 2011; Wang et al, 2022), compounds that benefit BPH fitness (Chen et al, 2011; Huang et al, 2015; Liu et al, 2021). Which compounds are responsible for the decrease in the performance of BPH on irDREB lines should be investigated in the future.…”

Integrated analysis of transcriptomics and metabolomics of peach under cold stress

“…As one of the most critical TFs functioning in the low-temperature signal transduction, C-repeat binding factors (CBFs) regulate the downstream gene expression, promote the synergy of multiple functional genes, and enhance the adaptability and resistance of plants ( Gilmour et al., 2000 ; Liu et al., 2022 ). It has been reported that overexpression of CBFs can stimulate the synthesis of soluble sugars (e.g., sucrose, raffinose, glucose and fructose) and improve the cold tolerance of pomegranate ( Wang et al., 2022 ). In this study, we identified three CBF genes (Prupe.4G242700, Prupe.5G090100 and Prupe.5G090000) were significantly upregulated in peach branches under cold stress ( Table S5 ).…”