In 2050, 9 billion people will be living on Earth and we need to ensure that they have the means to survive. Plants have an important part to play because they can be used to produce food, energy, clothes and raw materials. But we need to increase global agricultural production by up to 110% while a climate crisis is developing in order to support them.
Plant cell walls surround all plant cells and are composed mainly of carbohydrates like cellulose, which gives plant cells their shape and mechanical resistance. Indeed, cellulose microfibres have a strength similar to steel and form the main constituents of plant fibres, with obvious relevance for our daily life ranging from dietary fibre to clothing. But plant cell walls are also relevant to find new strategies to improve crop yield. A fundamental element is the cell wall integrity maintenance mechanism, which monitors the functional integrity of cell walls and initiates responses to maintain it during growth and in response to biotic, abiotic stress. Previous results indicated alterations in cell wall integrity modulate cell cycle activity. Intriguingly, plants with altered cell walls are more resistant to certain stress, and may even grow better. These two facts refer to a classic topic of plant science: the “growth-defence trade-off”, which means plants either allocate resources to growth or to defence. This explains why plants that are highly resistant to biotic/abiotic stresses are often also small and not very attractive for agricultural purposes. With this project, we want to understand how cell wall integrity and cell cycle activity are coordinated, thus possibly also understanding the “growth-defence trade-off” process. The results that we will obtain could be transferrable to species with agronomical importance, thus creating novel opportunities to address one of the biggest challenges of this century: to improve crop plant performance to support an increasing world population in a sustainable way.
Plant cell walls are essential for plant development and survival. As a matter of fact, around 10% of the genes encoded by the model plant Arabidopsis thaliana are involved in cell wall-related processes, highlighting its critical relevance. This importance explains the increasing interest in this research area. However, there is limited understanding of the molecular mechanisms involved in regulating cell wall synthesis, wall modification in response to stress or during development, and coordination with physiological processes.
One key element of plasticity appears to be the cell wall integrity (CWI) maintenance mechanism. This mechanism constantly monitors the functional integrity of the wall and initiates adaptive responses to CWI impairment. The host group identified a core set of CWI maintenance components through a phenotypic clustering approach, including receptor kinases, mechano-/osmo-sensitive channels and other signalling components, which are potentially involved in the detection of stimuli indicating alterations in CWI and in coordinating downstream responses.
The objective of this project is to understand how the cell cycle is coordinated with CWI. This coordination has been described in other organisms such as yeasts, but not in plants. By understanding this coordination, this project aims to gain insights into the classical "growth-defense trade-off", a term used to describe the situation where plants invest resources in defence mechanisms at the expense of plant growth. We will characterise the impact of different types of cell wall impairment on the cell cycle, and investigate the signalling processes that contribute to this coordination. Additionally, we will identify novel molecular components involved in this process, and establish the impact of disruptions to CWI on plant fitness. Finally, we will identify candidate genes that could form the basis to develop new strategies to improve the performance of food and bioenergy crops.