A "mille-feuilles" of stress tolerance in the desert plant Zygophyllum dumosum Boiss. Highlighting epigenetics

Plants thriving in harsh desert environments provide a suitable bio-system for unraveling novel mechanisms for survival under seasonal climate change and combination of temperature extremes, low water and nutrient availability and high salinity and radiation levels. The study of the desert plant Zygophyllum dumosum Boiss in its the natural habitat of the Negev desert revealed that stress tolerance is achieved by a plethora of mechanisms (e.g. morphological, molecular and developmental mechanisms), which are probably regulated by multiple genes that act together to bring about tolerance. Of particular interest is the finding that Z. dumosum like other Zygophyllaceae species, most of which inhabit dry and semidry regions of the world, do not possess the repressive epigenetic markers of histone H3 di- A nd tri-methylated at lysine 9; yet they possess mono methyl H3K9. We discuss the adaptive value of lessening epigenetic constraints with regard to the opportunistic behavior that makes plants most adaptable to change.