Role of magnesium in alleviation of aluminium toxicity in plants

Abstract

Magnesium is pivotal for activating a large number of enzymes; hence, magnesium plays an important role in numerous physiological and biochemical processes affecting plant growth and development. Magnesium can also ameliorate aluminium phytotoxicity, but literature reports on the dynamics of magnesium homeostasis upon exposure to aluminium are rare. Herein existing knowledge on the magnesium transport mechanisms and homeostasis maintenance in plant cells is critically reviewed. Even though overexpression of magnesium transporters can alleviate aluminium toxicity in plants, the mechanisms governing such alleviation remain obscure. Possible magnesium-dependent mechanisms include (i) better carbon partitioning from shoots to roots; (ii) increased synthesis and exudation of organic acid anions; (iii) enhanced acid phosphatase activity; (iv) maintenance of proton-ATPase activity and cytoplasmic pH regulation; (v) protection against an aluminium-induced cytosolic calcium increase; and (vi) protection against reactive oxygen species. Future research should concentrate on assessing aluminium toxicity and tolerance in plants with overexpressed or antisense magnesium transporters to increase understanding of the aluminium-magnesium interaction.

Nutritional Aspects of Grape (<i>Vitis vinifera</i> L.) Clusters Afflicted with SOUR Shrivel Is Related to Functionality of Its Vascular Tissues

“…Unlike the nutrients discussed thus far, aluminum (Al) is not an essential element, rather it is toxic to plants. Surprisingly, the healthy berries accumulated high amounts of aluminum (Al) but it also coincided with the highest amount of Mg, which is known to alleviate Al toxicity [30].…”

A Magnesium Transporter OsMGT1 Plays a Critical Role in Salt Tolerance in Rice

“…concentration, which prevents Al 3+ binding to oxygen donor compounds because Al 3+ and Mg 2+ ions have similar hydrated radius (Bose et al, 2011).…”

Magnesium mobility in soils as a challenge for soil and plant analysis, magnesium fertilization and root uptake under adverse growth conditions

“…The upregulation of a Mg transporter under Al stress was accompanied by increased Mg uptake by the rice plant through enhanced V max of the protein. Whether the increased tolerance of rice due to increased Mg uptake is a consequence of a specific Mg function or of the more efficient metabolic regulation of Mg-associated pathways in the plant as described by Bose et al (2011), remains to be elucidated. Future work should clarify the exact underlying mechanisms as well.…”