Al Toxicity in Yeast (A Role for Mg?)

MacDiarmid, Colin W.; Gardner, Richard C.

doi:10.1104/pp.112.3.1101

Cited by 55 publications

(50 citation statements)

References 27 publications

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“…However, the two cations were equally effective in alleviating Al rhizotoxicity at millimolar concentrations (Silva et al, 2001bc). MacDiarmid & Gardner (1996) also reported that the toxic effect of Al 3+ on Sacharomyces cerevisae was mitigated by Mg supplementation, unlike similar additions of Ca to the growth medium. Furthermore, it was recently reported that the overexpression of an Arabidopsis magnesium transport gene in Nicotiana benthamiana increased Mg uptake in the presence of Al and conferred Al tolerance (Deng et al, 2006).…”

Section: Introductionmentioning

confidence: 98%

“…In fact, aluminum is chemically more similar to Mg than to Ca (Martin, 1990) and competitively inhibits Mg uptake by plant roots (Rengel & Robinson, 1989). This Al-induced Mg deficiency has been suggested as a primary cause of Al toxicity (MacDiarmid & Gardner, 1996). Support for this hypothesis comes from research where overexpression of yeast and bacterial Mg transporters in yeast increased Mg (Co 2+ ) uptake and improved Al tolerance significantly (Fowler et al, 1999) and the more recent findings that overexpression of an Arabidopsis magnesium transport gene in Nicotiana benthamiana increased Mg uptake in the presence of Al and conferred Al tolerance (Deng et al, 2006).…”

Section: Protective Effect Of Magnesium On Distinct Root Classes Of 1mentioning

confidence: 99%

“…Alternatively, the Mg role is internal, but Al blocks the Mg transport via phloem from one part of the root system (comparment 2) to the other (compartment 1). Additionally, based on the decreasing trend of Mg root contents grown in compartment 1 in the presence of Al (T7 to T11) in comparison to control plants grown in the absence of Al (T1 to T5; Figure 5b), it can not be completely ruled out that the main toxic Al effect is due to an Al-induced Mg-deficiency (Rengel & Robinson, 1989;MacDiarmid & Gardner, 1996;Fowler et al, 1999). In fact, in yeast there are indications that Al toxicity occurs as a result of reduced Mg 2+ influx via the Alr proteins and overexpression of the Mg transport system led to a greater Al tolerance (MacDiarmid & Gardner, 1998).…”

Section: Protective Effect Of Magnesium On Distinct Root Classes Of 1mentioning

confidence: 99%

“…Several ions are known as ameliorators of Al rhizotoxicity in plants, especially Ca and Mg. Because of their abundance or reduced availability in acid soils, the protective role of Ca and Mg against Al rhizotoxicity has been extensively investigated (Gonzalez-Erico et al, 1979;Alva et al, 1986;Kinraide & Parker, 1987;Keltjens & Dijkstra, 1991;Rengel, 1992;Brady et al, 1993;Keltjens & Tan, 1993;MacDiarmid & Gardner, 1996;Ryan et al, 1997;Kinraide, 1998;Sanzonowicz et al, 1998;Ferrufino et al, 2000;Silva et al, 2001a).…”

Section: Introductionmentioning

confidence: 99%

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Timing, location and crop species influence the magnitude of amelioration of aluminum toxicity by magnesium

Silva

Corrêa

Novais

et al. 2009

Rev. Bras. Ciênc. Solo

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The protective effect of cations, especially Ca and Mg, against aluminum (Al) rhizotoxicity has been extensively investigated in the last decades. The mechanisms by which the process occurs are however only beginning to be elucidated. Six experiments were carried out here to characterize the protective effect of Mg application in relation to timing, location and crop specificity: Experiment 1 - Protective effect of Mg compared to Ca; Experiment 2 - Protective effect of Mg on distinct root classes of 15 soybean genotypes; Experiment 3 - Effect of timing of Mg supply on the response of soybean cvs. to Al; Experiment 4 - Investigating whether the Mg protective effect is apoplastic or simplastic using a split-root system; Experiment 5 - Protective effect of Mg supplied in solution or foliar spraying, and Experiment 6 - Protective effect of Mg on Al rhizotoxicity in other crops. It was found that the addition of 50 mmol L-1 Mg to solutions containing toxic Al increased Al tolerance in 15 soybean cultivars. This caused soybean cultivars known as Al-sensitive to behave as if they were tolerant. The protective action of Mg seems to require constant Mg supply in the external medium. Supplying Mg up to 6 h after root exposition to Al was sufficient to maintain normal soybean root growth, but root growth was not recovered by Mg addition 12 h after Al treatments. Mg application to half of the root system not exposed to Al was not sufficient to prevent Al toxicity on the other half exposed to Al without Mg in rooting medium, indicating the existence of an external protection mechanism of Mg. Foliar spraying with Mg also failed to decrease Al toxicity, indicating a possible apoplastic role of Mg. The protective effect of Mg appeared to be soybean-specific since Mg supply did not substantially improve root elongation in sorghum, wheat, corn, cotton, rice, or snap bean when grown in the presence of toxic Al concentrations.

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Section: Introductionmentioning

confidence: 98%

Section: Protective Effect Of Magnesium On Distinct Root Classes Of 1mentioning

confidence: 99%

Section: Protective Effect Of Magnesium On Distinct Root Classes Of 1mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Timing, location and crop species influence the magnitude of amelioration of aluminum toxicity by magnesium

Silva

Corrêa

Novais

et al. 2009

Rev. Bras. Ciênc. Solo

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“…Al is also known as a potent neurotoxin in animal cells and its relevance to Alzheimer's disease is hotly debated (Exley, 1999). Al can cause toxicity in micro-organisms as well (MacDiarmid & Gardner, 1996). Al toxicity induces programmed cell death in yeast (Zheng et al, 2007), plants (Yakimova et al, 2007) and animals (Kawahara, 2005).…”

Section: Introductionmentioning

confidence: 99%

The crucial role of mitochondrial regulation in adaptive aluminium resistance in Rhodotorula glutinis

et al. 2008

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Rhodotorula glutinis IFO1125 was found to acquire increased aluminium (Al) resistance from 50 mM to more than 5 mM by repetitive culturing with stepwise increases in Al concentration at pH 4.0. To investigate the mechanism underlying this novel phenomenon, wild-type and Alresistant cells were compared. Neither cell type accumulated the free form of Al (Al 3+ ) added to the medium. Transmission electron microscopic analyses revealed a greater number of mitochondria in resistant cells. The formation of small mitochondria with simplified cristae structures was observed in the wild-type strain grown in the presence of Al and in resistant cells grown in the absence of Al. Addition of Al to cells resulted in high mitochondrial membrane potential and concomitant generation of reactive oxygen species (ROS). Exposure to Al also resulted in elevated levels of oxidized proteins and oxidized lipids. Addition of the antioxidants a-tocopherol and ascorbic acid alleviated the Al toxicity, suggesting that ROS generation is the main cause of Al toxicity. Differential display analysis indicated upregulation of mitochondrial genes in the resistant cells. Resistant cells were found to have 2.5-to 3-fold more mitochondrial DNA (mtDNA) than the wild-type strain. Analysis of tricarboxylic acid cycle and respiratory-chain enzyme activities in wild-type and resistant cells revealed significantly reduced cytochrome c oxidase activity and resultant high ROS production in the latter cells. Taken together, these data suggest that the adaptive increased resistance to Al stress in resistant cells resulted from an increased number of mitochondria and increased mtDNA content, as a compensatory response to reduced respiratory activity caused by a deficiency in complex IV function.

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A potential contribution of the less negatively charged cell wall to the high aluminum tolerance of Rhodotorula taiwanensis RS1

Zhao

Bao

et al. 2016

Yeast

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Rhodotorula taiwanensis RS1 (Rt) is a high-aluminum (Al)-tolerant yeast that can survive Al at concentrations up to 200 mM. In this study, we compared Rt with an Al-sensitive congeneric strain, R. mucilaginosa AKU 4812 (Rm) and Al sensitive mutant 1 (alsm1) of Rt, to explore the Al tolerance mechanisms of Rt. The growth of Rm was completely inhibited by 1 mM Al, but that of Rt was not inhibited until Al concentration was more than 70 mM. The growth of alsm1 was inhibited much more by 70 mM and 100 mM Al than that of Rt. Compared with Rm cells, Rt cells accumulated less Al in the cell wall and cytoplasm. A time-course analysis showed that Al was absorbed by Rm cells much more rapidly than by Rt cells when exposed to the same Al concentration. Meanwhile, the Al content of alsm1 was higher than that of Rt. Although the cell wall of Rt was thicker than that of alsm1 and Rm under control and 0.1 mM Al, that of Rt was thinner than that of alsm1 under 70 mM Al despite that their cell walls were thickened. The alcian blue adsorption was lower and cell wall zeta-potential was higher in Rt and alsm1 than in Rm, indicating a less negative charge of cell wall of Rt and alsm1 than that of Rm. Taken together, the less negatively charged cell wall of Rt may restrict the adsorption of cationic Al in cells, potentially contributing to its high Al tolerance. Copyright © 2016 John Wiley & Sons, Ltd.

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Al Toxicity in Yeast (A Role for Mg?)

Abstract: We discuss the relevance of yeast as a model for the study of AI toxicity in plant systems.

Cited by 55 publications

References 27 publications

Timing, location and crop species influence the magnitude of amelioration of aluminum toxicity by magnesium

Timing, location and crop species influence the magnitude of amelioration of aluminum toxicity by magnesium

The crucial role of mitochondrial regulation in adaptive aluminium resistance in Rhodotorula glutinis

A potential contribution of the less negatively charged cell wall to the high aluminum tolerance of Rhodotorula taiwanensis RS1

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