[Organic acid secretion and its detoxification mechanism in plant roots under aluminum stress].

Phytotoxicity of Al is becoming one of the most serious problems in limiting plant growth on acid soils. Under Al stress, a number of plant species, cultivars or genotypes exhibit inheritable tolerance by organic acid secretion which is specific to Al stress and localized to the root apex. Citric acid, oxalic acid and malic acid are thought to be the most effective organic acids in detoxifying Al. Organic acid detoxifies Al both extracellular and intracellular. Two exudation patterns and their related speculation are introduced in this review. The possible factors responsible for the organic acid secretion are discussed, which are also the research focuses in this field. At last, we put forward our perspective in the field.