Dataset Information

Antagonism between blue and red light-signalling controls thallus flatness in Marchantia polymorpha

ABSTRACT: The growth orientation of the Marchantia polymorpha thallus – a system of dorsiventralized, indeterminate axes – is modulated by light. We show that red and blue light act antagonistically to control thallus flatness, with red light signalling promoting epinasty and blue light signalling promoting hyponasty. We found that loss-of-function mutations in the blue light receptor MpPHOT led to epinasty, while loss-of-function mutations in the red light receptor MpPHY resulted in hyponasty. We hypothesize that these antagonistic activities of blue and red light signalling are balanced in white light, resulting in the development of flat thalli. Using time-resolved transcriptomics, we identified genes that were rapidly induced upon light exposure. Among these genes were all six members of the M. polymorpha BBX gene family. Mutants harbouring loss-of-function mutations in two of the six MpBBX transcription factors developed defective thalli. Mpbbx1 loss-of-function mutants formed hyponastic thalli, while Mpbbx5 loss-of-function mutants developed epinastic thalli. Double mutants Mpbbx1 Mpbbx5 grew flat, supporting the hypothesis that they function antagonistically. Together, these data indicate that phototropin-mediated blue light and phytochrome-mediated red light signalling antagonistically modulate thallus flatness, and that BBX transcription factors also act antagonistically to regulate thallus flatness.

ORGANISM(S): Marchantia polymorpha

PROVIDER: GSE316508 | GEO | 2026/01/21

REPOSITORIES: GEO

ACCESS DATA

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

Project description:Background: Potato (Solanum tuberosum L.) is the fourth largest food crop worldwide with significant economic value and importance for food security. Shade avoidance syndrome (SAS) considerably affects crop architecture and productivity in high-density planting systems; however, its molecular mechanisms in potato remain poorly understood. Methods: Potato seedlings were subjected to four light treatments simulating different shade signals: white light (control, WL), low blue light (LBL, simulating blue light attenuation by plant canopies), low red:far-red ratio (WL+FR, simulating far-red reflection from neighboring plants), and their combination (LBL+FR, simulating complete plant shade environment). We conducted a comprehensive study integrating morphological characterization, leaf anatomical analysis, hormone quantification, transcriptome sequencing, and metabolite profiling. Results: Morphological analysis revealed that WL+FR primarily induced internode elongation (+20.0%) and leaf hyponasty, while LBL promoted stem elongation through increased node production (+36.3%). When combined, these signals (LBL+FR) synergistically enhanced stem elongation by 79.3%. Anatomical examination showed that LBL-treated leaves formed thickened palisade tissue layers (176.34 μm) with 6-7 layers of spongy tissue, whereas WL+FR resulted in thinner leaves (151.22 μm). Transcriptomic analysis identified 6,057 differentially expressed genes enriched in photosynthesis, hormone signaling, and carbohydrate metabolism pathways. A total of 1,168 differentially accumulated metabolites were detected across treatments, particularly organic acids and lipids associated with TCA (tricarboxylic acid) cycle and starch-sucrose metabolism. Weighted gene co-expression network analysis (WGCNA) identified PHYTOCHROME A (PHYA) as the central hub gene coordinating SAS responses under combined light stress, significantly diverging from the PHYB-centric model established in Arabidopsis.

Project description:The red-light regulated transcription factors FHY3 and FAR1 form a key point of light input to the plant circadian clock in positively regulating expression of genes within the central clock. However, the fhy3 mutant shows an additional red light-specific disruption of rhythmicity which is inconsistent with this role. Here we demonstrate that only fhy3 and not far1 mutants show this red specific disruption of rhythmicity. We examined the differences in rhythmic transcriptome in red versus white light and reveal differences in patterns of rhythmicity among the central clock proteins suggestive of a change in emphasis withing the central mechanism of the clock, changes which underlie the red specificity of the fhy3 mutant. In particular, changes in enrichment of promoter elements were consistent with a key role for the HY5 transcription factor, a known integrator of the ratio of red to blue light in regulation of the clock. Examination of differences in the rhythmic transcriptome in the fhy3 mutant in red light which identified specific disruption of the CCA1-regulated ELF3 and LUX central clock genes, while the CCA1 target TBS element, TGGGCC, was enriched among genes that became arrhythmic. Coupled with the known interaction of FHY3 but not FAR1 with CCA1 we propose that the red-specific circadian phenotype of fhy3 may involve disruption of the previously-demonstrated moderation of CCA1 activity by FHY3 rather than a disruption of its own transcriptional regulatory activity. Together, this evidence suggests a conditional redundancy between FHY3 and HY5 in the integration of red and blue light input to the clock in order to enable a plasticity in response to light and optimise plant adaptation. Furthermore, our evidence also suggests changes in CCA1 activity between red and white light transcriptomes. This, together with the documented interaction of HY5 with CCA1, leads us to propose a model whereby this integration of red and blue signals may at least partly occur via direct FHY3 and HY5 interaction with CCA1 leading to moderation of CCA1 activity.

Dataset Information

Antagonism between blue and red light-signalling controls thallus flatness in Marchantia polymorpha

Dataset's files

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets