Phytochrome A–dependent phosphorylation of AHP3 regulates
cytokinin-mediated photomorphogenesis

a 2025

Phytochrome A–dependent phosphorylation of AHP3 regulates cytokinin-mediated photomorphogenesis

SKALÁK, Jan

Základní údaje

Originální název

Phytochrome A–dependent phosphorylation of AHP3 regulates cytokinin-mediated photomorphogenesis

Autoři

SKALÁK, Jan

Vydání

TANGENC Conference 2025, Brno, 2025

Další údaje

Jazyk

angličtina

Typ výsledku

Konferenční abstrakt

Obor

10611 Plant sciences, botany

Stát vydavatele

Česká republika

Utajení

není předmětem státního či obchodního tajemství

Odkazy

URL

Označené pro přenos do RIV

Ano

Kód RIV

RIV/00216224:14740/25:00143979

Organizační jednotka

Středoevropský technologický institut

Klíčová slova anglicky

Phytochrome A; phyA; Cytokinin signaling; Multistep phosphorelay; MSP; AHP3 phosphorylation; Far-red light signaling

Štítky

rivok

Příznaky

Mezinárodní význam, Recenzováno

Změněno: 16. 3. 2026 10:49, Mgr. Eva Dubská

Anotace

V originále

The coordination of light and hormone signaling is essential for the regulation of plant growth and development. Cytokinin signaling is mediated by a multistep phosphorelay (MSP) pathway, but its regulation by light remains incompletely understood. Here we investigate the role of phytochrome A (phyA) in the modulation of cytokinin signaling under far-red light conditions. Using a cytokinin-responsive reporter system, we observed a rapid suppression of MSP activity following far-red illumination, indicating that phyA acts as a negative regulator of cytokinin-mediated responses. Protein interaction analyses revealed that phyA physically interacts with the histidine phosphotransfer protein AHP3. Mass spectrometry identified a conserved serine motif (Ser87–90) in AHP3 as a phosphorylation site. Functional analyses suggest that serine phosphorylation of AHP3 affects its affinity for histidine kinase receiver domains and inhibits phosphate binding at the histidine residue, thereby modulating phosphotransfer efficiency in the MSP pathway. These findings indicate that phyA-mediated phosphorylation of AHP3 represents a regulatory mechanism linking far-red light perception with cytokinin signaling.

Návaznosti

EH22_008/0004581, projekt VaV

Název: Nové poznatky pro plodiny nové generace

Přiložené soubory

5_TALK_24.11.2025_Skalak_TANGENC.pptx

Citovat

SKALÁK, Jan. Phytochrome A–dependent phosphorylation of AHP3 regulates cytokinin-mediated photomorphogenesis. In TANGENC Conference 2025, Brno. 2025.

@proceedings{2560920,
   author = {Skalák, Jan},
   booktitle = {TANGENC Conference 2025, Brno},
   keywords = {Phytochrome A; phyA; Cytokinin signaling; Multistep phosphorelay; MSP; AHP3 phosphorylation; Far-red light signaling},
   language = {eng},
   title = {Phytochrome A–dependent phosphorylation of AHP3 regulates cytokinin-mediated photomorphogenesis},
   url = {https://www.ceitec.eu/tangenc-conference-2025/a5272},
   year = {2025}
}

TY  - CONF
ID  - 2560920
AU  - Skalák, Jan
PY  - 2025
TI  - Phytochrome A–dependent phosphorylation of AHP3 regulates cytokinin-mediated photomorphogenesis
KW  - Phytochrome A
KW  - phyA
KW  - Cytokinin signaling
KW  - Multistep phosphorelay
KW  - MSP
KW  - AHP3 phosphorylation
KW  - Far-red light signaling
UR  - https://www.ceitec.eu/tangenc-conference-2025/a5272
N2  - The coordination of light and hormone signaling is essential for the regulation of plant growth and development. Cytokinin signaling is mediated by a multistep phosphorelay (MSP) pathway, but its regulation by light remains incompletely understood. Here we investigate the role of phytochrome A (phyA) in the modulation of cytokinin signaling under far-red light conditions. Using a cytokinin-responsive reporter system, we observed a rapid suppression of MSP activity following far-red illumination, indicating that phyA acts as a negative regulator of cytokinin-mediated responses. Protein interaction analyses revealed that phyA physically interacts with the histidine phosphotransfer protein AHP3. Mass spectrometry identified a conserved serine motif (Ser87–90) in AHP3 as a phosphorylation site. Functional analyses suggest that serine phosphorylation of AHP3 affects its affinity for histidine kinase receiver domains and inhibits phosphate binding at the histidine residue, thereby modulating phosphotransfer efficiency in the MSP pathway. These findings indicate that phyA-mediated phosphorylation of AHP3 represents a regulatory mechanism linking far-red light perception with cytokinin signaling.
ER  -

SKALÁK, Jan. Phytochrome A–dependent phosphorylation of AHP3 regulates cytokinin-mediated photomorphogenesis. In \textit{TANGENC Conference 2025, Brno}. 2025.

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