Team leader: Sabine Carpin, PhD
Associate Professors:
Sabine Carpin PhD (HDR), Christiane Depierreux PhD, François Héricourt PhD (HDR), Frédéric Lamblin PhD (HDR)
Engineer and technician:
Françoise Chefdor PhD, Mélanie Larcher
Context
Earth's climate has changed throughout history and a global climate change is observed due to human activities. The last IPCC report confirms that extreme events and disasters as drought will become more intensive. In our regions, more intensive and frequent droughts will lead to reduced water availability to food crop, forest and populiculture.
Poplar culture which is economically important in the « Région Centre - Val de Loire », is typically restricted to well irrigated zones and will be consequently strongly affected by more drastic drought events. In the future, one major issue for poplar culture in this context will be to understand signaling pathways which contribute to perceive the stress leading to poplar adaptation to drought.
Such signaling pathways have been identified and one of them corresponds to a multi-step phosphorelay system (MSP). This kind of signaling pathway is composed by three partners : a receptor belonging to the Histidine-aspartate Kinase familly (HK), a shuttle protein belonging to the Histidine-containing Phosphotransfer protein family (HPt), and a third partner belonging to the Response Regulator protein family (RR) which comprises transcription factors (RR-B).
In poplar, we identified two HK proteins (HK1a and b) which could play a role in drought perception (Chefdor et al., 2006 ; Héricourt et al., 2016), 10 HPt proteins (HPt1 to 10) (Héricourt et al., 2013), 9 RR-B (Bertheau et al., 2012 ; 2013 ; 2015) and 10 RR-A (Chefdor et al., 2018).
A preferential partnership was identified between some of these proteins as shown in the Figure below.
Scheme of MSP potentialy involved in perception of drought in poplar
MSP partners and their relationship
Project
Cytokinins have been shown as negative regulators during drought (Tran et al., 2007) and it is now accepted that these phytohormones can play a role in plant acclimation/adaptation/tolerance during drought via MSP pathway (Li et al., 2016). Indeed, the key to understand abiotic stress tolerance resides in understanding the plant’s capacity to accelerate/maintain or repress growth (Dolferus 2014).
Consequently, plants constantly oscillate between normal or stress conditions thus between growth (acceleration or maintain) and stress tolerance (growth repression) via a shared MSP pathway between these two signals, cytokinin and drought.
However, understanding how both signals, drought and cytokinins, perceived by distinct receptors, can result in specific responses through an identical pool of HPt and RR-B proteins, remains to be determined.
Our project focus on the study of MSP signaling pathways, trying to understand how those signaling pathway could permit plants to conserve specific responses to both signals and continue to grow during drought.
Our aims :
- To study HK1a and b roles and their operating mechanism
- To confirm the specificity between HPt2, 7 and 9 with HK1 compared to cytokinin receptors (HK2, 3 and 4).
- To study the roles of RR-B partners of HPt2, 7 and 9.
- To study RR-A roles in drought signaling.
Techniques
In vitro culture, hydroponic culture, protoplasts transformation, poplar agrotransformation, yeast two-hybrid, classical molecular biology techniques (RNA and DNA extraction, cloning techniques, sequencing, PCR, RT-PCR, western blot, etc …)
Poplar transformation
2H test RR18/HPt
Students training by research
- PhD thesis
- Hanae Makhokh (defended on 21st decembre 2023)
- Inès Djeghdir (defended on 15th decembre 2016)
- Lucie Bertheau (defended on 19th decembre 2013)
- Françoise Chefdor (defended on 19th decembre 2006)
- Master degree
- Master Agrosciences, Environnement, Territoires, Paysage, Forêt, Orléans
Spécialité Biologie Intégrative et Changements Globaux
- Master Science du Vivant, Orléans
Spécialité Biotechnologie, Biologie Moléculaire et Cellulaire
- Master Biologie des Plantes et des Micro-organismes, Biotechnologies, Bioprocédés, Montpellier
Spécialité Biologie des Plantes
- Master Biologie, Agronomie, Santé, Rennes
Spécialité Sciences Cellulaire et Moléculaire du Vivant
- Undergraduate degree
- Licence 3 parcours BOPE et BBMC, Orléans
- BTS Biotechnologies, Lycée Jacques Monod, St Jean de Braye