Biology subjects

Falavigna, V. d. S.

Publications and source records attributed to Falavigna, V. d. S..

2 recordsLinked to original sources

bioRxiv2025

MdBRC1 and MdFT2 Interaction Fine-Tunes Bud Break Regulation in Apple

Winter bud dormancy is a critical adaptive process in temperate fruit trees, safeguarding meristems from freezing temperatures and aligning growth with seasonal cues. Dormancy encompasses two primary phases: endodormancy, where internal signals, particularly elevated abscisic acid (ABA), block growth and necessitate chilling for release; and ecodormancy, where buds regain growth competence but remain quiescent until external conditions are favourable. In apple (Malus domestica), we demonstrated that BRANCHED1 (MdBRC1) serves as a central inhibitor of bud growth specifically during ecodormancy. In many plant species, BRC1-like transcription factors integrate environmental and hormonal signals, activating gene networks linked to growth repression, notably those involved in ABA biosynthesis and signalling. Gain-of-function studies in poplar confirmed that MdBRC1 robustly suppresses shoot growth in trees. Our comparative transcriptomic analyses revealed that MdBRC1 directly regulates a suite of dormancy-associated genes, reinforcing its role as a molecular brake on bud break. Importantly, we show that the apple gene FLOWERING LOCUS T2 (MdFT2) is transcriptionally upregulated after dormancy and might act as a key inducer of bud break. Our data reveal that MdFT2 physically interacts with MdBRC1, reducing MdBRC1 activity during ecodormancy. This antagonistic interaction acts as a molecular switch, facilitating the transition from ecodormancy to active bud growth as spring approaches. Together, these findings uncover a regulatory module that finely tunes bud break timing in apple trees and provide a foundation for breeding strategies to enhance fruit tree resilience and adaptability in the context of climate change.

plant biology↗

bioRxiv2021

Unraveling the role of MADS transcription factor complexes in apple tree dormancy using sequential DAP-seq

BackgroundThe effect of global warming on dormancy and flowering patterns of crop trees threatens world-wide fruit production and food security. In Rosaceous tree species, it is believed that a group of genes encoding MADS transcription factors (TFs) controls temperature-mediated dormancy cycle. These genes are similar to SHORT VEGETATIVE PHASE (SVP) from Arabidopsis thaliana and referred as DORMANCY-ASSOCIATED MADS-BOX (DAM) genes. ResultsBy making use of apple tree (Malus x domestica) as a model for Rosaceous species, we have investigated the function of MADS TFs during the dormancy cycle. We found that MdDAM and other dormancy related MADS TFs form multimeric complexes with MdSVPa, and that MdSVPa is essential for the transcriptional complex activity. Then, for the first time in non-model plant species, we performed sequential DNA Affinity Purification sequencing (seq-DAP-seq) to define the genome-wide binding sites of these MADS TF complexes. Target genes associated with the binding sites were identified by combining seq-DAP-seq data with transcriptomics datasets obtained by the inducible glucocorticoid receptor expression system, and reanalyzing preexisting data related to dormancy cycle in apple trees. ConclusionWe have determined a gene regulatory network formed by MdSVPa-containing complexes that regulate the dormancy cycle in apple trees in response to environmental cues. Key genes identified with our genomic approach and the elucidated regulatory relationships provide leads for breeding fruit trees better adapted to changing climate conditions. Moreover, we provide novel molecular evidence on the evolutionary functional segregation between DAM and SVP proteins in the Rosaceae family.

plant biology↗