This post was originally published on the UK Plant Sciences Federation blog.
Photosynthesis is a major target area for crop improvement. In July 2014, I caught up with three plant scientists researching photosynthesis to discover their latest findings, which were presented at the Society for Experimental Biology’s annual main meeting in Manchester.
Understanding evolutionary intermediates between two photosynthetic pathways
Marjorie Lundgren, a PhD student at the University of Sheffield, is researching how different photosynthetic mechanisms evolve. She works on the grass Alloteropsis semialata, which is unique in having both C3 and C4 photosynthetic pathways within this single species. Excitingly, her work has discovered populations of this species with intermediate photosynthetic phenotypes (known as C2 plants), helping us to understand how C4 evolves from the C3 pathway.
Marjorie’s research has three main findings. Firstly, she’s confirmed the existence of intermediate photosynthetic states using a range of physiological techniques. Secondly, she’s established that this intermediacy arose in Central Africa. And finally, Marjorie has elucidated clear links between environment, leaf anatomy and physiology. Together, her preliminary work suggests that leaf anatomical traits which are important for the C3 to C4 transition respond to environmental changes. This responsiveness is known as phenotypic plasticity and may affect the evolution of photosynthetic types.
“There’s a huge amount of variation within this species,” says Marjorie. “It’s a brilliant system.” Marjorie hopes that her research will inform the multinational C4 rice consortium, which aims to introduce the efficient C4 photosynthetic pathway into rice. She is working to identify important anatomical turning points in the evolutionary process which leads from C3 to C4 photosynthesis.
The next challenge is to use this wild grass species to identify the genetic variation that underpins evolution of the C4 photosynthetic pathway, and see how it affects physiology. This understanding is crucial if we are to successfully engineer C4 traits into C3 plants to improve crop efficiency and yield. (more…)