Accelerating climate change and intensifying anthropogenic activities have increasingly subjected plants to a wide spectrum of abiotic stresses, among which soil salinity, recurrent drought, and heavy metal contamination represent the most severe constraints on plant growth and productivity. While the stress responses of many short-rotation crop species have been extensively explored, comparatively little attention has been devoted to tree species, despite their pivotal ecological and economic roles. In this context, Populus alba and its interspecific hybrids have recently gained prominence as model systems for investigating abiotic stress responses in woody perennials, owing to their rapid growth, adaptation to Mediterranean climatic conditions, and the availability of comprehensive genomic resources. Emerging evidence indicates that stress tolerance in poplars is governed by the dynamic regulation of stress-responsive transcription factors, complex hormonal signalling networks, and downstream genes involved in key metabolic processes, including antioxidant defence. To facilitate a clearer understanding of these mechanisms, a critical synthesis of existing research is required. Accordingly, this review provides an integrated overview of stress-responsive genes, their associated signalling pathways, and the physiological mechanisms underlying tolerance to major abiotic stresses such as drought, salinity, and metal toxicity, with particular emphasis on P. alba and its hybrids. Collectively, the insights presented herein advance our understanding of tree stress biology and offer a valuable foundation for developing resilient genotypes to sustain plantation forestry under increasingly challenging environmental conditions.
Tiwari et al. (Sun,) studied this question.