MAC3A and MAC3B Modulate FLOWERING LOCUS M Splicing to Repress Photoperiod-Dependent Floral Transition
Journal
Plant, Cell and Environment
Journal Issue
Online Version of Record before inclusion in an issue
ISSN
0140-7791
1365-3040
Date Issued
2025-06-02
Author(s)
Huang, Yu‐Wen
Tseng, Chih‐Yen
Wang, Yu‐Sen
Tu, Yi‐Tsung
Hsieh, Hsin‐Yu
Ly, Yun‐Tung
Chen, Yu‐Zhen
Tu, Shih‐Long
Abstract
Plants adjust their flowering time by integrating environmental cues through complex regulatory networks. RNA splicing plays a crucial role in modulating gene expression in response to flowering signals. The MOS4-associated complex (MAC), consisting of the evolutionarily conserved E3 ubiquitin ligases MAC3A and MAC3B, is pivotal in splicing regulation. However, their involvement in floral transition remained unclear. This study observed that mac3a/mac3b mutants flowered significantly earlier under short-day (SD) conditions, a phenotype absent under long-day (LD) conditions. This early flowering correlated with upregulation of FLOWERING LOCUS T (FT) and SUPPRESSOR OF OVEREXPRESSION OF CO 1 (SOC1) compared to wild-type plants. Transcriptomic analysis revealed alterations in transcript levels and splicing profiles of key floral regulators across different flowering pathways. Further investigation identified the thermosensory flowering regulator FLOWERING LOCUS M (FLM) as being influenced by MAC3A and MAC3B. Subsequently, we found that MAC3A and MAC3B exhibited higher expression in SD and were associated with FLM transcripts to modulate their splicing. This study elucidates how the MAC complex, through RNA splicing regulation, integrates environmental signals to modulate flowering, unveiling a new layer of complexity in flowering pathways crosstalk under non-inductive photoperiods.
Subjects
alternative splicing
ambient temperature
FLC
FLM
flowering time
MAC3A
MAC3B
photoperiod
Publisher
Wiley
Type
journal article