Project description:We are studying the tree P. euphratica growing in its natural habitat in the Negev desert in Israel. We have used leaf RNA samples from trees growing from four different areas in the desert valley Ein Avdat with contrasting growth conditions, with the primary factor being how much water the trees have access to. Area A trees grow close to a stream. Area B trees are further away from the stream. Area C trees are growing on a slope with no water. Parking place trees grow at a parking place (1km from Area A, B and C) where there is a water irrigation system, and these trees are regularly watered once a week. The control sample in each hybridization is always RNA isolated from a pool of 5 trees from the parking place. The hybridizations are comparing the following: Area A -- parking place Area B -- parking place Area C -- parking place Each hybridization is done with a dye swap and three different biological repeats for a total of 18 hybridizations.