The Arbuscular Mycorrhiza (AM) symbiosis   is a mutual association formed by plant roots and soil fungi. Most vascular flowering plants have the ability to form AM associations, which have significant impact on ecosystem function and plant health. This association is based on the mutual exchange of nutrients between plant and fungus. Therefore, AM association leads to increased demands for photosynthesis. The main aim of this study was to investigate the pathway used by plants during AM to increase the photosynthetic performance. To achieve this aim we used the model legume Medicago truncatula. AM symbiosis develops in roots where AM fungi colonize the roots, leading to better plant growth and more biomass. Furthermore, AM symbiosis increases chlorophyll content and photosynthetic electron transport rate (ETR)   in leaves. Based on these results we suggest that AM symbiosis increases both efficiency and capacity of photosynthetic apparatus in Medicago truncatula.

Keywords:   Arbuscular symbiosis (AM), Medicago truncatula, electron transport rate (ETR), chlorophyll, and photosynthesis.