Engineering Crassulacean Acid Metabolism (CAM) Pathways In Plants

Disclosed herein are method of altering CAM pathways in plants. In some examples, a disclosed method includes overexpressing one or more genes encoding one or more enzymes that carry out the basic biochemical sequence of nocturnal CO.sub.2 fixation (carboxylation) into C.sub.4 acids (malate), store C.sub.4 acids in the vacuole of the plant, and/or then decarboxylate and refix the released CO.sub.2 by C.sub.3 photosynthesis during the subsequent day in a plant cell, thereby altering CAM in the plant cell. Also disclosed herein are isolated polynucleotide sequences, transformation vectors, transgenic plant cells, plant part, and plants. The disclosed methods and compositions can be used to improve the water-use efficiency and drought tolerance and durability of plants, such as in plants in arid environments, and also enhance the ability of plants to perform.