Although abundant in soils, iron (Fe) is poorly bioavailable for plants. Improving Fe uptake in crops, enabling them to grow in Fe-depleted soils, has become a major focal interest. The secretion of Fe-mobilizing coumarins by plant roots recently emerged as an important factor allowing nongrass species to cope with low Fe bioavailability. The main molecular actors involved in the biosynthesis and secretion of coumarins have been identified, but the precise regulatory mechanisms that tune their production remain poorly understood. Here, we review the recent progress in coumarin synthesis and transport in plants and future research directions to gain knowledge of these mechanisms, which will offer novel opportunities for improving plant growth and health and for generating Fe-fortified crops.

铁（Fe）虽然在土壤中含量丰富，但对植物的生物利用度却很差。改善农作物对铁的吸收使其能够在贫铁土壤中生长已成为人们关注的主要焦点。最近，植物根部分泌动员铁的香豆素成为重要的因素，使非草种能够应对低的铁生物利用度。香豆素的生物合成和分泌中涉及的主要分子参与者已被确定，但调节其产生的精确调控机制仍知之甚少。在这里，我们回顾了香豆素在植物中合成和运输的最新进展以及未来的研究方向，以了解这些机理，这将为改善植物生长和健康以及生产铁强化作物提供新的机会。