Photosynthetic organisms often face fluctuations in light intensity. The knowledge of the molecular mechanisms that enable exceptionally adaptable species to survive extreme environments is of paramount importance for understanding the patterns of plant evolution in changing climate. The most vulnerable to high light is Photosystem II (PSII). However, PSII possess a protective mechanism against excess light via dissipating excess energy in into heat, called NPQ.
The molecular mechanism of NPQ includes generation in high light of a proton gradient across the membrane that affects the structural state of PSII light harvesting antenna (LHCII), that collects and delivers light energy for the reaction center.
Whilst there has been a lot of progress made towards establishment of a molecular mechanism of NPQ little if none is known about how efficiently it works in different plant species and why some of them like Hedera helix can equally well adopt to extreme shade and excessively high light. Indeed, such knowledge would offer an invaluable insight on the molecular factors that determine efficient and fast light- tracking of the light environment by plants without compromising the PSII quantum efficiency. Therefore, the key objective of this program is to apply an array of biochemical, spectroscopic and physiological approaches to find out what molecular factors of the photosynthetic membrane are actually enabling Hedera helix to live in the various light environments.