Floral Induction Mechanisms in Tropical Fruit Trees

Floral induction in tropical fruit trees is orchestrated by a complex interplay of environmental cues and endogenous signals. Many species require a period of low temperature to perceive a floral trigger, during which leaves and apical meristems translate temperature, water status and oxidative signals into developmental programmes. Chilling accumulation interacts with water deficit and reactive oxygen species to activate transcription factors and hormone pathways, notably those involving abscisic acid, ethylene and gibberellins. Central to this process is the upregulation of florigen-encoding genes, which promote the transition from vegetative to reproductive meristems. Carbohydrate metabolism and source–sink relations further modulate floral bud formation, with sucrose and starch levels serving both as energy reserves and signalling molecules. Practical treatments such as controlled drought, cryoprotectants or stem girdling can enhance flowering by fine-tuning these metabolic and hormonal networks. Understanding these mechanisms is essential to adapt tropical fruit production to climate change by guiding breeding for cultivars with lower chilling requirements and improved yield stability.

Research from Nature Portfolio

Recent studies have revealed how combined drought and low-temperature regimes synergistically enhance floral induction in subtropical fruit trees. Transcriptome analyses showed that a preconditioning drought applied before chilling significantly increased the expression of flowering-related transcription factors and a homolog of Flowering Locus T, indicating an integrative stress response that primes the meristem for reproductive development. In parallel, investigations into reactive oxygen species and chilling interactions have mapped a network of co-expressed genes in apical meristems: these include stress-responsive regulators, hormone biosynthesis enzymes and key flowering-time genes. Together, these findings delineate a coordinated regulatory circuit by which oxidative signals and sub-optimal temperatures converge to trigger floral fate in tropical perennials.

Floral Induction Mechanisms in Tropical Fruit Trees publication trend

The graph below shows the total number of articles in floral induction mechanisms in tropical fruit trees across all publications each year (not limited to Nature Index journals).

Technical terms

Chilling accumulation: The cumulative exposure of plant tissues to temperatures below a species-specific threshold, necessary to break dormancy and induce flowering.

Florigen: A mobile flowering signal, often encoded by FT-like genes, that moves from leaves to the shoot apical meristem to initiate reproductive development.

Reactive oxygen species (ROS): Chemically reactive molecules derived from oxygen that act as signalling agents in stress-induced flowering pathways.

Inflorescence meristem: The specialised shoot apical meristem region that differentiates into flower structures following floral induction.

Transcriptome: The complete set of RNA transcripts produced in a cell or tissue, used to profile gene expression during floral induction.

References

1. Impact of flowering temperature on litchi yield under climate change: A case study in Taiwan. Climate Services (2024).
2. Integrative effect of drought and low temperature on litchi (Litchi chinensis Sonn.) floral initiation revealed by dynamic genome-wide transcriptome analysis. Scientific Reports (2016).
3. RNA-seq analysis of apical meristem reveals integrative regulatory network of ROS and chilling potentially related to flowering in Litchi chinensis. Scientific Reports (2017).
4. Identification of Chilling Accumulation-Associated Genes for Litchi Flowering by Transcriptome-Based Genome-Wide Association Studies. Frontiers in Plant Science (2022).
5. Metabolomics Analysis of Litchi Leaves during Floral Induction Reveals Metabolic Improvement by Stem Girdling. Molecules (2021).
6. Cryoprotectant-Mediated Cold Stress Mitigation in Litchi Flower Development: Transcriptomic and Metabolomic Perspectives. Metabolites (2024).