Biology subjects

Yoo, C. Y.

Publications and source records attributed to Yoo, C. Y..

5 recordsLinked to original sources

bioRxiv2025

Identification of a putative RBOHD-FERONIA-CRK10-PIP2;6 plasma membrane complex that interacts with phyB to regulate ROS production in Arabidopsis thaliana

O_LIReactive oxygen species (ROS) regulate plant growth, development, and responses to the environment. ROS production by the RESPIRATORY BURST OXIDASE PROTEIN D (RBOHD) protein was recently shown to be regulated by PHYTOCHROME B (phyB), and phyB was found to be phosphorylated by FERONIA, highlighting the possibility that these three proteins interact to regulate ROS levels during stress. C_LIO_LIImmunoprecipitation and proximity labelling, followed by split-luciferase and functional validation assays, were used to study the interactions between FERONIA, phyB, and RBOHD during excess light (EL) stress in Arabidopsis thaliana. C_LIO_LIWe reveal that phyB and FERONIA interact with RBOHD, that phosphorylation of phyB by FERONIA, as well as the kinase activity of FERONIA, are required for RBOHD-driven ROS production in response to EL stress, and that CYSTEINE-RICH RECEPTOR LIKE KINASE 10 (CRK10) and PLASMA MEMBRANE INTRINSIC PROTEIN 2;6 (PIP2;6) interact with RBOHD and phyB and are also required for EL-driven RBOHD ROS production. C_LIO_LIOur findings uncover the existence of a putative plasma membrane complex between FERONIA, RBOHD, CRK10, and PIP2;6 that interacts with phyB to regulate ROS production in Arabidopsis in response to stress. This complex could play a canonical role in the integration and regulation of multiple signaling pathways in plants. C_LI Plain Language SummaryWe identified a complex between several different proteins at the plasma membrane that interacts with the light and temperature receptor protein phytochrome B to regulate reactive oxygen species formation during stress in plants. This complex could be involved in the regulation and integration of multiple abiotic and biotic signals in plants. tenten

plant biology↗

bioRxiv2025

Proximity proteomics reveals the molecular architecture of phytochrome B photobodies in Arabidopsis thaliana

The red/far-red light photoreceptor phytochrome B (phyB) forms light-induced subnuclear condensates, termed photobodies, that coordinate plant responses to light and temperature. Despite their central role in environmental signaling, the molecular composition of phyB photobodies during their early formation has remained unknown. Here, we established an in planta proximity labeling approach using miniTurbo-based biotinylation in Arabidopsis thaliana to capture proteins associated with phyB photobodies during early de-etiolation. Mass spectrometry identified 42 high-confidence proximal proteins, including 11 known core components and 31 previously unrecognized photobody-associated proteins. Among these, the co-chaperone HOP1 forms light-dependent nuclear condensates that partially co-localize with phyB photobodies. HOP1 condensates are smaller in the wild-type background than in phyB-overexpressing seedlings, and HOP1 overexpression enhanced cotyledon expansion under red light. These findings suggest that HOP1 contributes to photomorphogenesis by stabilizing phyB photobodies and sustaining active phyB signaling. Together, our results reveal that nascent large phyB photobodies function as dynamic hubs integrating chaperone-mediated protein quality control with transcriptional regulation, providing the first in planta proteomic framework for understanding photobody assembly and signaling in plants.

plant biology↗

bioRxiv2025

Cis-regulatory variation in ISOCHORISMATE SYNTHASE 1 modulates systemic salicylic acid biosynthesis and systemic acquired resistance in plants

Systemic acquired resistance (SAR) is a long-distance immune response that protects uninfected plant tissues following a localized pathogen attack. In the model plant Arabidopsis thaliana, SAR depends on the systemic accumulation of salicylic acid (SA), mediated by the transcription factor CCA1 HIKING EXPEDITION (CHE), which activates the SA biosynthetic gene ISOCHORISMATE SYNTHASE1 (ICS1). However, the conservation and functional significance of the CHE-ICS1 regulatory module across plant species remain poorly understood, particularly in the Brassicaceae, where ICS1 is the major contributor to SA biosynthesis among two known pathways: the ICS1 and PHENYLALANINE AMMONIA-LYASE (PAL) routes. Here, we identify natural variation in cis-regulatory elements within the ICS1 promoter that affects CHE binding across species. In multiple Brassicaceae species with divergent cis-element sequences, CHE fails to regulate ICS1, leading to the absence of systemic ICS1 induction and SA accumulation following pathogen infection. Despite this deficiency, SAR still occurs in these species, albeit to a lesser extent than in species with successful systemic induction of SA mediated by an intact CHE-ICS1 regulatory module. Interestingly, introducing the CHE-ICS1 module into species lacking this interaction confers systemic SA accumulation, highlighting the potential to enhance systemic immunity through cis-element modification. Our findings demonstrate that sequence variation in a cis-regulatory element underlies the interspecies diversification of SAR regulatory mechanisms and highlight the evolutionary plasticity of plant immune signaling. This study provides a molecular framework for engineering enhanced systemic immunity in crops, particularly within the Brassicaceae, through the targeted modification of cis-regulatory elements that regulate SA biosynthesis.

plant biology↗

bioRxiv2024

Transcriptional repression of GTL1 under water-deficit stress promotes anthocyanin biosynthesis to enhance drought tolerance

The transcription factor GT2-LIKE 1 (GTL1) has been implicated in orchestrating a transcriptional network of diverse physiological, biochemical, and developmental processes. In response to water-limiting conditions, GTL1 is a negative regulator of stomatal development, but its potential role in other water-deficit responses is unknown. We hypothesized that GTL1 regulates transcriptome changes associated with drought tolerance over leaf developmental stages. To test the hypothesis, gene expression was profiled by RNA-seq analysis in emerging and expanding leaves of wild-type and a drought-tolerant gtl1-4 knockout mutant under well-watered and water-deficit conditions. Our comparative analysis of genotype-treatment combinations within leaf developmental age identified 459 and 1073 differentially expressed genes in emerging and expanding leaves, respectively, as water-deficit responsive GTL1-regulated genes. Transcriptional profiling identified a potential role of GTL1 in two important pathways previously linked to drought tolerance: flavonoid and polyamine biosynthesis. In expanding leaves, negative regulation of GTL1 under water-deficit conditions promotes biosynthesis of flavonoids and anthocyanins that may contribute to drought tolerance. Quantification of polyamines did not support a role for GTL1 in these drought-responsive pathways, but this is likely due to the complex nature of synthesis and turnover. Our global transcriptome analysis suggests that transcriptional repression of GTL1 by water deficit allows plants to activate diverse pathways that collectively contribute to drought tolerance.

plant biology↗

bioRxiv2021

Direct photoresponsive inhibition of a p53-like transcription activation domain in PIF3 by Arabidopsis phytochrome B

Phytochrome B (PHYB) triggers diverse light responses in Arabidopsis by binding to a group of antagonistically acting PHYTOCHROME-INTERACTING transcription FACTORs (PIFs) to promote PIF degradation, consequently downregulating PIF target genes. However, whether PHYB directly controls the transactivation activity of PIFs remains ambiguous. Here we show that the prototypic PIF, PIF3, possesses a p53-like transcription activation domain (TAD) consisting of a sequence-specific, hydrophobic activator motif surrounded by acidic residues. A PIF3mTAD mutant in which the activator motif is replaced with alanines fails to activate PIF3 target genes in Arabidopsis in dark, light, and shade conditions, validating the in vivo functions of the PIF3 TAD. Intriguingly, binding of PHYBs N-terminal photosensory module to the PHYB-binding site adjacent to the TAD inhibits its transactivation activity. These results unveil a photoresponsive transcriptional switching mechanism in which photoactivated PHYB directly masks the transactivation activity of PIF3. Our study also suggests the unexpected conservation of sequence-specific TADs between the animal and plant kingdoms.

plant biology↗