Physiological responses and tolerance of citrus to aluminum toxicity

Abstract

Aluminum (Al) toxicity is the major factor limiting plant growth in acidic soils, which comprise up to 50% of the world's potentially arable lands. Citrus belong to evergreen subtropical fruit trees and are cultivated in humid and subhumid of tropical, subtropical, and temperate regions of the world mainly on acidic soils. Soil acidification is a major problem in citrus plantations. There has been significant progress in our understanding of the physiological responses and the tolerance of citrus to Al toxicity during the past decade. In this chapter, growth, physiological responses (carbohydrates, photosynthesis, water relation, light energy utilization, photoprotective system, mineral nutrients, and organic acids), and tolerance (genotypic differences, Al uptake, and distribution, and Al-induced secretion of organic acid anions) of citrus to Al toxicity are reviewed. The amelioration of phosphorus (P) and boron (B) on citrus Al toxicity as well as some aspects needed to be further studied are also discussed.