From QTL mapping to genome editing: advances and integrated strategies for improving aluminum tolerance in crops

Aluminum (Al) toxicity in acidic soils remains one of the most serious constraints on global crop production, limiting productivity across nearly one-third of the world's potentially arable land. As pressure grows to cultivate marginal lands under climate change and food security challenges, improving Al tolerance has become an urgent priority in crop science and sustainable agriculture. This review provides a timely synthesis of recent advances in the genetic and molecular dissection of Al tolerance, highlighting the progression from classical biparental QTL mapping to genome-wide association studies and, more recently, CRISPR/Cas-based precision editing. Major breakthroughs, including the identification of key ALMT and MATE transporters, the expansion of STOP1-centered regulatory networks, and the discovery of the first Al receptor, have greatly deepened our understanding of plant adaptation to acid soils. We further examine how high-throughput phenotyping, marker-assisted selection, genomic selection, and gene pyramiding are accelerating the translation of genetic discoveries into breeding practice. Importantly, emerging genome-editing strategies now enable targeted and potentially transgene-free improvement of endogenous tolerance genes. By integrating molecular breeding with agronomic approaches such as liming and nutrient management, this review outlines a forward-looking framework for developing resilient crop varieties and achieving more sustainable productivity on acidic soils worldwide.