植物抗旱性研究进展

In recent years, global climate change has intensified the effects of critical environmental stressors, such as drought, flooding, and extreme temperatures, on plant growth and crop yield. Drought stands out as a major meteorological hazard due to its high frequency, prolonged duration, and widespread impact. Drought is not only prevalent in arid and semi-arid regions, but may also trigger stress in areas with higher annual precipitation where uneven distribution occurs during the growing season. As a significant abiotic stress, drought constrains plant growth and diminishes crop yields. A deeper understanding of drought’s effects on plant growth and development, the molecular regulatory networks underlying plant responses to drought stress, and the exploration of drought-resistant gene resources will advance the establishment and expansion of the theoretical framework in plant stress biology. These efforts will further provide theoretical foundations and genetic resources for molecular design breeding of drought-resistant crops. This review summarizes major advances in drought resistance research in Arabidopsis thaliana and major crops. The first section elucidates the signal transduction pathway of abscisic acid (ABA) and the molecular mechanisms of transcriptional regulation in response to drought stress. Under drought conditions, formation of the ABA complex (PYR/PYL/RCAR-ABA-PP2C) releases SnRK2 protein kinases, which subsequently phosphorylate and activate downstream transcription factors (ABI5 and AREBs). These transcription factors bind to ABA-responsive elements (ABREs) in the promoters of ABA-dependent genes. Meanwhile, DREB transcription factor, also known as CBFs, regulates the stress-inducible expression of genes via ABA-independent pathways. The promoters of these drought-responsive genes frequently harbor the dehydration-responsive cis-element (DRE). Drought detrimentally affects plants by reducing germination, suppressing leaf expansion and tillering, diminishing dry matter accumulation, and decreasing grain yield. Plants have evolved physiological and molecular mechanisms to mitigate these damaging effects. The second section details the molecular mechanisms of drought stress signal perception and transduction, as well as the impact of drought on plant growth and development. Specific aspects include leaf epicuticular wax deposition, stomatal development and movement, root growth, and reproductive development. Here, we summarize recent progress in cloning and functionally characterizing drought resistance genes, alongside technological advances developed to alleviate drought’s threat to crop production. Our results further suggest that the integration of multi-omics data, more reference genome information, and robust statistical analyses is likely to facilitate the identification of other causal genes associated with drought resistance. Elucidating how plants perceive and respond to drought stress at the molecular level is fundamental to developing molecular approaches for enhancing crop tolerance. Molecular breeding approaches, such as marker-assisted selection, gene pyramiding, and genome editing, can fully utilize the growing repository of favorable alleles to precisely improve drought-resistant traits. Finally, this article summarizes representative achievements in drought resistance research over the past four decades (1984–2024) from the College of Biological Sciences at China Agricultural University. These findings provide both theoretical foundations and genetic resources for molecular design breeding of drought-tolerant and water-saving crop varieties.