Research Progress on DNA Methylation Regulating Flower Bud Differentiation and Flowering Phenotype in Plants

The Role of DNA Methylation in Plant Biotic Stress Responses

DNA methylation, a key epigenetic modification, is an important regulator of plant gene expression, coordinating development and responses to environmental signals. DNA methylation includes both cytosine methylation and adenine methylation. Cytosine methylation has been studied in plant immunity, while adenine methylation is emerging as a novel regulator. As part of its role in regulating gene expression, DNA methylation, so far mainly cytosine methylation, exhibits a dynamic behavior during biotic stresses. Indeed, several reports have explored the targets and regulatory capacity of DNA methylation-associated responses. This review summarizes recent advances in understanding dynamic changes in DNA methylation in plants exposed to a wide range of biotic threats, including viruses, fungi, oomycetes, bacteria, and insects, with examples on horticultural crops such as tomato, chrysanthemum, and citrus. We highlight how pathogen interactions trigger DNA methylation changes that can either activate plant defense mechanisms or be manipulated by pathogens to promote host susceptibility. We also discuss how pathogen effectors target host methylation machinery and the molecular basis of transgenerational epigenetic immune memory. Collectively, the evidences underscore DNA methylation as a critical battleground in plant-pathogen interactions across diverse plant species, pointing to its potential as a target for innovative crop improvement strategies.

Effect of DNA Methyltransferase Inhibitor on Flowering in Litchi Chinensis by Transcriptome and Proteome

Epigenetic Regulation of Stress Tolerance and Fruit Quality in Fruit Crops

This study examined the complex roles of epigenetic mechanisms—DNA methylation, histone modification, chromatin remodeling, and non-coding RNAs—in enhancing stress tolerance and regulating fruit quality traits.

Spatiotemporal-specific DNA methylation and small RNAs are involved to regulate cell cycle progression and organ development of cucumber (Cucumis sativus L.).

A dual mechanism in which DNA methylation and CsRDR1a-related small RNAs coordinately regulate cucumber organ development is unveiled, highlighting the importance of epigenetic regulation in cucumber.

Functions of the plant NuA4-C in shaping developmental gene expression patterns.

Chromatin remodeling plays a central role in regulating plant development and physiology by shaping the gene expression patterns that drive biological processes. Among epigenetic modifications, histone acetylation is particularly relevant as it alters chromatin structure and influences transcriptional activity. MYST-type histone acetyltransferases (HAT) are evolutionarily conserved components of the Nucleosome Acetyltransferase of histone H4 (NuA4) complex, a key regulator that acetylates histones H4, H2A, and the histone variant H2A.Z. Growing evidence supports the presence of a canonical NuA4-C in plants, similar to that described in yeast. In this review, we summarize recent studies that have begun to uncover its broad role in plant biology, highlighting its involvement in diverse processes such as the skoto- to photomorphogenesis switch, chloroplast development, shade avoidance responses, thermomorphogenesis, the vegetative-to-reproductive transition, plant growth, reproduction and hormonal signalling. In addition, we discuss recent advances in understanding the crosstalk of NuA4-C-mediated H4ac and H2A.Z deposition with other chromatin remodeling complexes in plants. Although significant progress has been made, a full understanding of the complex functions remains unavailable. Current evidence indicates that NuA4-C in yeast and TIP60 in humans are central regulators of transcription, acting not only through histone acetylation but also by influencing transcription elongation and RNA splicing, although direct evidence for similar functions in plant NuA4-C still remains limited. This regulatory role might be critical for integrating developmental programs with environmental signalling pathways. While initial insights into the recruitment of NuA4-C to target genes have emerged, further research is needed to clarify how its activity is controlled and modulated in different biological contexts.

Genetic Regulation of Photoperiod Sensitivity in Flowering Plants

Photoperiodism represents a critical adaptive mechanism enabling plants to synchronize flowering with optimal environmental conditions. This review examines the molecular and genetic foundations underlying photoperiod sensitivity in flowering plants, with particular emphasis on the model organism Arabidopsis thaliana. The photoperiodic flowering pathway integrates light signals through photoreceptors with endogenous circadian rhythms to regulate the expression of key floral integrators. Central to this process is the CONSTANS (CO) protein, which acts as a critical molecular switch whose stability and activity are regulated by both light quality and photoperiod length. Under long-day conditions, CO accumulates during the light period and activates transcription of FLOWERING LOCUS T (FT), encoding a mobile florigen signal that promotes flowering. This pathway involves complex regulatory networks including GIGANTEA (GI), FLAVIN-BINDING KELCH REPEAT F-BOX 1 (FKF1), and various E3 ubiquitin ligases that modulate CO protein stability. Understanding these genetic mechanisms holds significant implications for crop improvement, particularly in adapting agricultural species to changing climate conditions and expanding their geographical range. This review synthesizes current knowledge of photoperiod sensing mechanisms and highlights emerging areas for future research in plant developmental biology.