Mechanisms of aluminum-tolerance in two species of citrus: Secretion of organic acid anions and immobilization of aluminum by phosphorus in roots

▶ Citrus sinensis may more effectively acquire P than C. grandis. ▶ C. sinensis is more tolerant to Al than C. grandis. ▶ C. sinensis roots secrete more OA anions than C. grandis in response to Al. ▶ Al-tolerance of C. sinensis involves OA secretion and Al precipitation by P in roots.