Decoding the molecular control of bud dormancy release in trees

Informations projet

DECORE

N° de convention de subvention: 101025929

DOI

10.3030/101025929

Projet clôturé

Date de signature de la CE 6 Avril 2021

Date de début 1 Janvier 2022

Date de fin 26 Mars 2024

Financé au titre de

• EXCELLENT SCIENCE - Marie Skłodowska-Curie Actions

Coût total

€ 203 852,16

Contribution de l’UE

€ 203 852,16

Coordonné par

SVERIGES LANTBRUKSUNIVERSITET
Sweden

Periodic Reporting for period 1 - DECORE (Decoding the molecular control of bud dormancy release in trees)

Période du rapport: 2022-01-01 au 2023-12-31

Résumé du contexte et des objectifs généraux du projet

• What is the problem/issue being addressed?

Plants lack a nervous system and central decision-making organ, but can nevertheless sense and respond to environmental cues, including seasonal cues that play crucial roles in regulating their growth and development, through poorly understood mechanisms. By exploring the interplay between gene expression, hormonal regulation, and cell-cell communication, we elucidated the mechanisms underlying the temperature-mediated control of bud dormancy. In this project we have provided an important insight into the molecular regulation of dormancy and the mechanism underlying seasonally aligned growth in trees by temperature.

• Why is it important for society?

In this project we have identified the role of AGL8-GA module in mediating PD opening and provided an important insight into the molecular regulation of dormancy and the mechanism underlying seasonally aligned growth in trees by temperature. This research project revealed the mysteries behind bud dormancy in trees by investigating the interactions between genes, hormones, and cell-cell communication. These findings will advance our understanding of how plants adapt to seasonal changes and contribute to the competitiveness of European research, particularly in the field of developmental adaptation to seasonal variations.


• What are the overall objectives?

This project aims to elucidate the molecular mechanisms underlying the temperature-mediated control of bud dormancy in the experimental model tree hybrid aspen. In this project we functionally characterized an unknown MADS-box transcription factor AGL8, which was previously identified in the host lab. In this project we focused on (1) If FT1 is a direct downstream target of AGL8 and AGL8-mediated FT1 activation is required for low temperature (LT) induced dormancy release, (2) If AGL8 is a LT-responsive transcriptional regulator of GA biosynthesis in buds, and if AGL8-mediated LT-induced GA biosynthesis is essential for LT-induced dormancy release, and (3) Whether AGL8 promotes dormancy release by transcriptionally activating the expression of GH17 endoglucanases which are believed to catalyse callose breakdown and a subsequent PD opening.

Travail effectué depuis le début du projet jusqu’à la fin de la période considérée dans le rapport et principaux résultats atteints jusqu’à présent

Main findings of this project are:

1. We identified a previously uncharacterized MADS-box transcription factor AGL8, which is induced by LT in buds and elucidated its role in LT mediated dormancy release.
2. Our genetic and gene expression data showed that AGL8 function as a positive regulator of FT1 and GA20-oxidase (involved in GA biosynthesis), providing a genetic link between LT and induction of FT1 and the GA pathway during dormancy release.
3. We showed LT-induced plasmodesmata (PD) opening in buds is mediated by AGL8-GA module. AGL8, as the LT-induced upstream regulator of the GA20-oxidase expression, provides a crucial genetic link between LT, activation of the GA pathway and PD opening in the buds.
4. We showed that AGL8 and FT1 pathways converge on shared targets in LT response of buds.

Temperature is a major environmental cue that regulates developmental transition in plants. In contrast with rapid responses to change in temperature, major developmental transitions such as vernalization or bud dormancy involve long term sensing of temperature input. Long term sensing of low temperature during vernalization is mediated by epigenetic silencing of FLC, a floral repressor in Arabidopsis. Whereas long term exposure to LT regulates bud dormancy in which control of cell-cell communication plays an important role. Our results reveal the complexity of this LT response in buds and show that AGL8 and FT1 form a coherent feedforward loop in dormancy release and negative feedback via GA on AGL8 that can contribute to robust regulation of bud dormancy by LT. Thus, by identifying the role of the AGL8-GA module in mediating PD opening, we have provided an important insight into the molecular regulation of dormancy and the mechanism underlying seasonally aligned growth in trees by temperature.
Researcher created a project page on Umeå Plant Science Centre (UPSC) website where the results were updated regularly. The researcher delivered two oral presentations at the host institution and CNRS, Bordeaux, during secondment. The researcher presented the project and MSCA program to the public during the annual ‘Fascination of Plants Day’ and held a workshop on the use of immunogold labelling and TEM analysis of PDs at the host institution.

Progrès au-delà de l’état des connaissances et impact potentiel prévu (y compris l’impact socio-économique et les conséquences sociétales plus larges du projet jusqu’à présent)

Main findings of this project are:

1. We identified a previously uncharacterized MADS-box transcription factor AGL8, which is induced by LT in buds and elucidated its role in LT mediated dormancy release.
2. Our genetic and gene expression data showed that AGL8 function as a positive regulator of FT1 and GA20-oxidase (involved in GA biosynthesis), providing a genetic link between LT and induction of FT1 and the GA pathway during dormancy release.
3. We showed LT-induced plasmodesmata (PD) opening in buds is mediated by AGL8-GA module. AGL8, as the LT-induced upstream regulator of the GA20-oxidase expression, provides a crucial genetic link between LT, activation of the GA pathway and PD opening in the buds.
4. We showed that AGL8 and FT1 pathways converge on shared targets in LT response of buds.

Temperature is a major environmental cue that regulates developmental transition in plants. In contrast with rapid responses to change in temperature, major developmental transitions such as vernalization or bud dormancy involve long term sensing of temperature input. Long term sensing of low temperature during vernalization is mediated by epigenetic silencing of FLC, a floral repressor in Arabidopsis. Whereas long term exposure to LT regulates bud dormancy in which control of cell-cell communication plays an important role. Our results reveal the complexity of this LT response in buds and show that AGL8 and FT1 form a coherent feedforward loop in dormancy release and negative feedback via GA on AGL8 that can contribute to robust regulation of bud dormancy by LT. Thus, by identifying the role of the AGL8-GA module in mediating PD opening, we have provided an important insight into the molecular regulation of dormancy and the mechanism underlying seasonally aligned growth in trees by temperature.
Researcher created a project page on Umeå Plant Science Centre (UPSC) website where the results were updated regularly. The researcher delivered two oral presentations at the host institution and CNRS, Bordeaux, during secondment. The researcher presented the project and MSCA program to the public during the annual ‘Fascination of Plants Day’ and held a workshop on the use of immunogold labelling and TEM analysis of PDs at the host institution.

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