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The red color of the pear peel in red-skinned European pear is due to the accumulation of anthocyanins. Numerous transcription factors play pivotal roles in anthocyanin biosynthesis, with zinc finger proteins frequently implicated in the regulation of this process via MYB10, as documented in earlier studies. In this article, we identified a zinc finger protein gene, named PbZAT12, that does not rely on PbMYB10, to regulate anthocyanin biosynthesis. The PbZAT12 protein was localized within the nucleus and exhibited a positive influence on the accumulation of anthocyanins in the peel of 'Red Zaosu' pears. Moreover, overexpression of PbZAT12 resulted in a significant up-regulation of PbDFR, PbANS, and PbUFGT expression levels in pear fruitlets. Y1H assays demonstrated a direct binding ability of PbZAT12 to proPbDFR, proPbANS, and proPbUFGT, which was supported by a dual luciferase assay, indicating its potential to activate the transcriptional activity of these promoters. However, in contrast to its effect on the aforementioned promoters, PbZAT12 did not exhibit an activation of PbMYB10. In summary, our findings suggest that a zinc finger transcription factor, PbZAT12, exerts a positive influence on anthocyanin biosynthesis in pear fruit through direct upregulation of the expression levels of PbDFR, PbANS, and PbUFGT. [ABSTRACT FROM AUTHOR]

Summary: Although the N6‐methyladenosine (m6A) modification is the most prevalent RNA modification in eukaryotes, the global m6A modification landscape and its molecular regulatory mechanism in response to drought stress remain unclear.Transcriptome‐wide m6A methylome profiling revealed that m6A is mainly enriched in the coding sequence and 3′ untranslated region in response to drought stress in apple, by recognizing the plant‐specific sequence motif UGUAH (H=A, U or C). We identified a catalytically active component of the m6A methyltransferase complex, MdMTA. An in vitro methyl transfer assay, dot blot, LC‐MS/MS and m6A‐sequencing (m6A‐seq) suggested that MdMTA is an m6A writer and essential for m6A mRNA modification.Further studies revealed that MdMTA is required for apple drought tolerance. m6A‐seq and RNA‐seq analyses under drought conditions showed that MdMTA mediates m6A modification and transcripts of mRNAs involved in oxidative stress and lignin deposition. Moreover, m6A modification promotes mRNA stability and the translation efficiency of these genes in response to drought stress. Consistently, MdMTA enhances lignin deposition and scavenging of reactive oxygen species under drought conditions.Our results reveal the global involvement of m6A modification in the drought response of perennial apple trees and illustrate its molecular mechanisms, thereby providing candidate genes for the breeding of stress‐tolerant apple cultivars. [ABSTRACT FROM AUTHOR]

Anthocyanins are common secondary metabolites in plants that impart red coloration to fruits and flowers. The important WRKY transcription factor family plays multifaceted roles in plant growth and development. In this study, we found a WRKY family gene, Pyrus bretschneideri WRKY75, that may be involved in anthocyanin synthesis in pear. Unlike Arabidopsis thaliana WRKY75, PbWRKY75 may be a positive regulator of anthocyanin synthesis. A transient expression assay indicated that PbWRKY75 promoted pear anthocyanin synthesis. The structural genes (PbANS, PbDFR, and PbUFGT) and positive regulators (PbMYB10 and PbMYB10b) of anthocyanin synthesis were significantly upregulated in the fruitlet skins of PbWRKY75‐overexpressing "Zaosu" pears. Subsequently, yeast one‐hybrid and dual‐luciferase assays indicated that PbWRKY75 promoted PbDFR, PbUFGT, and PbMYB10b expression by activating their promoters. These results revealed that PbWRKY75 may promote the expression of both PbMYB10b and anthocyanin late biosynthetic genes (PbDFR and PbUFGT) by activating their promoters, thereby inducing anthocyanin synthesis in pear. This study enhanced our understanding of the mechanism of pear anthocyanin synthesis, which will be beneficial in the improvement of pear peel color. [ABSTRACT FROM AUTHOR]