Metabolic and physiological adjustments of maize leaves in response to aluminum stress

Abstract

Acidic soils with elevated aluminum (Al) saturations are worldwide distributed and harm the crop production in most of the tropical and subtropical regions. Under these conditions, root elongation may be impaired and thus disturbs water and nutrient uptake. Consequently, physiological responses of plants challenged with excess Al may resemble those of drought stresses. Here, we hypothesized that drought tolerant plants are also Al tolerant due to changes in growth, metabolic and physiological adjustments in leaves. Two maize genotypes, BRS1010 and BRS1055, sensitive and tolerant to drought, respectively, were hydroponically grown under controlled conditions and challenged with two Al concentrations (0 and 100 lM AlCl 3) for 5 days. After treatment with Al, BRS1055 plants displayed increased leaf and stem elongation whereas the relative root growth rate remained unchanged. This was accompanied by unaltered root structure, photosynthetic efficiency and leaf primary metabolism. In sharp contrast, the BRS1010 plants were sensitive to Al, exhibiting a reduction in leaf and stem elongation and biomass accumulation in shoot and root, as well as greater structural damages in root tips. Additionally, in response to Al, lipid peroxidation increased in BRS1010 leaves in parallel to inhibition of photosynthetic performance and dark respiration. Moreover, compared to control treatment, the genotype BRS1010 displayed a large accumulation of sugars, amino acid, proteins and organic acids in leaves under Al stress. Therefore, the leaf physiology and metabolism are pivotal players in modulating Al tolerance in maize.

Coordinated Regulation of Central Carbon Metabolism in Pyroligneous Acid-Treated Tomato Plants under Aluminum Stress

“…Exposing the plants to 4 mM Al without PA increased the total TCA cycle metabolites by approximately 0.11-fold due to high levels of citric acid, aconitic acid, α-ketoglutaric acid and malic acid ( Figure 3 B). It has been established that primary metabolic constituents associated with Al tolerance are strongly linked to mitochondrial metabolism and OA production [ 2 , 4 , 8 ]. Organic acid production in response to Al stress is the most-characterized mechanism for Al tolerance, with citrate and malate being the common TCA cycle metabolites identified in several plants [ 4 , 8 , 13 ].…”

“…It has been established that primary metabolic constituents associated with Al tolerance are strongly linked to mitochondrial metabolism and OA production [ 2 , 4 , 8 ]. Organic acid production in response to Al stress is the most-characterized mechanism for Al tolerance, with citrate and malate being the common TCA cycle metabolites identified in several plants [ 4 , 8 , 13 ]. For instance, tomatoes produce and secrets malate, which chelate Al ions into non-toxic forms [ 50 ].…”

“…Al-induced buildup of ROS facilitates membrane lipid peroxidation, loss of Metabolites 2023, 13, 770 2 of 18 cell membrane integrity and damage to cellular components including nucleic acids and proteins [7]. Consequently, these phytotoxic effects result in marked yield reduction and total crop failure [4,8].…”

“…Mitochondrial metabolism plays an important role in Al tolerance by facilitating carbohydrate consumption for OA and cellular ATP biosynthesis [ 2 , 8 ]. Consequently, the glycolytic influx is increased under stress conditions to support not only energy production but also OA generation during Al detoxification.…”

γ-Aminobutyric Acid Priming Alleviates Acid-Aluminum Toxicity to Creeping Bentgrass by Regulating Metabolic Homeostasis

“…It has been reported that acid-Al stress significantly restrained elongation and dry mass accumulation of roots and shoots and also reduced RWC, Chl content, Pn, and WUE in leaves of apple ( Malus pumila ) or barley ( Hordeum vulgare ) seedlings [ 31 , 32 ]. As compared to Al-sensitive maize variety BRS1010, Al-tolerant BRS1055 accumulated less Al in shoots, accompanied by a significantly higher RGR of shoots under acid-Al stress [ 33 ]. Similar findings were obtained in the current study, which showed that acid-Al-induced growth retardant, Al enrichment, and declines in Chl content, Pn, and photochemical efficiency could be significantly mitigated by the GABA priming in creeping bentgrass plants.…”