The goal of the current research was to study the role of anthocyanin accumulation, O2-related photochemical processes and non-photochemical quenching (NPQ) in the response of desert and Mediterranean plants to drought and excessive light.Plants of Hordeum spontaneum were collected from Mediterranean and desert environments and were subjected to terminal drought for 25 days and then measured for PSII yield at 2 and 21% O2, NPQ, net carbon assimilation, stomatal conductance, leaf relative water content (LRWC), anthocyanin concentration and leaf absorbance.Under terminal drought, LRWC, carbon assimilation and stomatal conductance decreased similarly and significantly in both the Mediterranean and the desert ecotypes. Anthocyanin accumulated more in the desert ecotype than in the Mediterranean ecotype. NPQ increased more in the Mediterranean ecotype as compared with the desert ecotype. PSII yield decreased significantly in the Mediterranean ecotype under drought and was much lower than in the desert ecotype under drought. The relatively high PSII yield under drought in the desert ecotype was O2 dependent.The response of the H. spontaneum ecotype from a desert environment to drought stress was characterized by anthocyanin accumulation and induction of O2 dependent photochemical activity, while the response of the Mediterranean ecotype was based on a higher induction of NPQ.
Bibliographical noteFunding Information:
We would like to thank Alexander Goldberg and Prof. Arnon Karnieli from the Remote Sensing Lab at the Jacob Blaustein Institutes for Desert Research, for helping with the leaf absorbance measurements. The research was supported by the FP7 IRG .
- Non photochemical quenching