Molecular mechanism and adaptive value of leaf shape plasticity in the genus Capsella.

• Applicant: Professor Dr. Michael Lenhard, since 9/2017
• Subject Area: Plant Cell and Developmental Biology
• Term: from 2016 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 290460955

Plants as sessile organisms are strongly exposed to their environment and therefore had to evolve elaborate mechanisms to adapt their development and physiology to ambient conditions. Since climate is highly unpredictable in nature and fluctuates considerably over days, months and years, these adaptations need to be dynamic and plastic. Indeed, plants have to be able to rapidly sense their environment and optimise their metabolism and growth accordingly to best perform in those conditions. The leaf is one of the most plastic organs in plants. Their biological function obliges leaves to find a balance between developing a sufficient surface area to optimise gas exchange and the amount of light that can be captured, while minimizing their exposure to stressful conditions. As a result, the final size and shape of leaves are highly dependent on growing conditions. A long standing observation is that the level of leaf dissection negatively correlates with temperature. However, very little is known about the molecular mechanisms that integrate temperature signals into leaf development and how the resulting changes in leaf geometry may contribute to fitness. The proposed project aims to take advantage of our recent findings on the genetic basis of temperature-induced leaf shape plasticity in the genus Capsella to investigate the molecular and ecological relationship between climate, leaf surface area and overall plant fitness. In this genus, a decrease in ambient temperature activate the expression of the REDUCED COMPLEXITY 3 (RCO-3) gene, which in turn increase the dissection level of the leaves. Polymorphisms within this locus between two sister species of this genus underlie natural variation in leaf shape and RCO-3 temperature response. This allelic variation in RCO-3 temperature perception offers a unique opportunity to dissect the molecular mechanisms and ecological consequences associated with temperature-induced leaf shape plasticity.

• DFG Programme: Research Grants
• Ehemaliger Antragsteller: Dr. Adrien Sicard, until 8/2017