Understanding plant tolerance to aluminum: exploring mechanisms and perspectives

Abstract

Aluminum (Al) is the third, most abundant element in the Earth's crust. When soil pH drops below 5.5, Al is released from minerals, which threatens plant growth. The roots are particularly vulnerable to Al stress because Al ions can penetrate them, causing growth reduction by inhibiting the cell cycle and decreasing root cell elongation. Al has the ability to bind to cell structures, including cell walls, cytoskeleton, or DNA, which disturb their functions. Plants have developed various response strategies, such as the exclusion of organic acids into the rhizosphere or the detoxification of Al in the vacuole. STOP1 (Sensitive To Proton Rhizotoxicity 1) is the critical regulator of the expression of tolerance-related genes and is present in both mono- and dicots plants. The activity of STOP1 can be regulated on post-transcription and post-translation levels. This review paper presents an overview of the latest literature, aiming to accurately present the problem of Al toxicity and its effect on plant functioning. Moreover, the well-studied mechanisms of plant response and future prospects, like the use of polyamines, miRNAs, or DDR (DNA Damage Response) pathway, will be presented, which are opportunities to develop new plant varieties that are tolerant to Al stress.