CAM Plants under Global Climate Change: Genetic, Metabolic, and Ecophysiological Aspects

Crassulacean Acid Metabolism (CAM) represents an alternative pathway of carbon fixation that enables plants to achieve high water-use efficiency and maintain competitive advantages under warm and arid climatic conditions. CAM plants are not only ecologically significant but also serve as important crops for food, feed, and bioenergy production, demonstrating exceptional resilience to climate change. Over the past decade, advances in systems biology, omics technologies, and bioinformatics have significantly deepened our understanding of CAM evolution, diel metabolic regulation, and environmentally induced CAM expression. In parallel, innovative genetic engineering approaches, including CRISPR/Cas-based techniques, have expanded the potential to introduce CAM traits into drought-sensitive major crops, improving their drought tolerance and productivity. In this review, we provide a comprehensive analysis of the molecular, metabolic, physiological, and ecological characteristics of CAM plants. We also highlight promising research directions, focusing on metabolic pathways, regulatory networks, and stress-responsive signaling systems, with the aim of predicting ecophysiological responses and evaluating the prospects for practical application of CAM traits in agriculture under global climate change.