Oxalic Acid/Oxalates in Plants:From Self-Defence to Phytoremediation

Oxalic acid and oxalates are produced and present in plants in different amounts. Insoluble calcium oxalate plays a key role in regulating calcium concentration, which is important in the functioning of guard cells. Oxalates provide tolerance to aluminium toxicity to plants growing in acid soils. Both oxalic acid and calcium oxalate provide self-defence against insect pests and grazing animals. Oxalates are involved in phytoremediation of soils rendered toxic by heavy metals, like lead, cadmium, zinc, etc.