Arabidopsis thaliana AtHAL3: a flavoprotein related to salt and osmotic tolerance and plant growth

Espinosa‐Ruíz, Ana; Bellés, José María; Serrano, Ramón; Culiáñez-Macià, Francisco A.

doi:10.1046/j.1365-313x.1999.00626.x

Cited by 159 publications

(82 citation statements)

References 39 publications

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“…Arabidopsis mutants in the PDX1.3 gene for pyridoxal 59-phosphate synthase were found to be hypersensitive to salt, osmotic, and oxidative stress (Chen and Xiong, 2005;Titiz et al, 2006). (2) Pantothenate/coenzyme A: The Arabidopsis HAL3A (HALOTOLERANCE DETERMINANT 3A) gene, first identified for its relation to stress tolerance (EspinosaRuiz et al, 1999), was shown to code for a key enzyme in pantothenate conversion to coenzyme A (Kupke et al, 2001), and HAL3A overexpression increased salt tolerance (Espinosa-Ruiz et al, 1999;Yonamine et al, 2004). (3) .…”

Section: Modern Evidencementioning

confidence: 99%

Does Abiotic Stress Cause Functional B Vitamin Deficiency in Plants?

et al. 2016

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B vitamins are the precursors of essential metabolic cofactors but are prone to destruction under stress conditions. It is therefore a priori reasonable that stressed plants suffer B vitamin deficiencies and that certain stress symptoms are metabolic knock-on effects of these deficiencies. Given the logic of these arguments, and the existence of data to support them, it is a shock to realize that the roles of B vitamins in plant abiotic stress have had minimal attention in the literature (100-fold less than hormones) and continue to be overlooked. In this article, we therefore aim to explain the connections among B vitamins, enzyme cofactors, and stress conditions in plants. We first outline the chemistry and biochemistry of B vitamins and explore the concept of vitamin deficiency with the help of information from mammals. We then summarize classical and recent evidence for stress-induced vitamin deficiencies and for plant responses that counter these deficiencies. Lastly, we consider potential implications for agriculture.

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Section: Modern Evidencementioning

confidence: 99%

Does Abiotic Stress Cause Functional B Vitamin Deficiency in Plants?

et al. 2016

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“…Plants that overexpress the gene encoding the AtHAL3A PPCDC showed improved growth under salt and osmotic stress (Espinosa-Ruiz et al, 1999). Overexpression of tobacco (Nicotiana tabacum) HAL3 also enhanced salt and osmotic stress tolerance in cultured tobacco cells (Yonamine et al, 2004).…”

Section: Overexpression Of Ppat Leads To Enhanced Growth and Salt/osmmentioning

confidence: 99%

The Coenzyme A Biosynthetic Enzyme Phosphopantetheine Adenylyltransferase Plays a Crucial Role in Plant Growth, Salt/Osmotic Stress Resistance, and Seed Lipid Storage

et al. 2008

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Coenzyme A (CoA) is an essential cofactor in the metabolism of both prokaryotic and eukaryotic organisms and a universal five-step pathway is utilized to synthesize CoA from pantothenate. Null mutations in two of the five steps of this pathway led to embryo lethality and therefore viable reduction-of-function mutations are required to further study its role in plant biology. In this article, we have characterized a viable Arabidopsis (Arabidopsis thaliana) T-DNA mutant affected in the penultimate step of the CoA biosynthesis pathway, which is catalyzed by the enzyme phosphopantetheine adenylyltransferase (PPAT). This ppat-1 knockdown mutation showed an approximately 90% reduction in PPAT transcript levels and was severely impaired in plant growth and seed production. The sum of CoA and acetyl-CoA levels was severely reduced (60%–80%) in ppat-1 seedlings compared to wild type, and catabolism of storage lipids during seedling establishment was delayed. Conversely, PPAT overexpressing lines showed, on average, approximately 1.6-fold higher levels of CoA + acetyl-CoA levels, as well as enhanced vegetative and reproductive growth and salt/osmotic stress resistance. Interestingly, dry seeds of overexpressing lines contained between 35% to 50% more fatty acids than wild type, which suggests that CoA biosynthesis plays a crucial role in storage oil accumulation. Finally, biochemical analysis of the recombinant PPAT enzyme revealed an inhibitory effect of CoA on PPAT activity. Taken together, these results suggest that the reaction catalyzed by PPAT is a regulatory step in the CoA biosynthetic pathway that plays a key role for plant growth, stress resistance, and seed lipid storage.

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“…For instance, in oilseed plants the use of storage lipids during early seedling establishment is a key process for plant survival that is CoA dependent (Graham and Eastmond, 2002). Additionally, as CoA biosynthesis appears to be a sensitive step in plants under salt stress (Espinosa-Ruiz et al, 1999;Yonamine et al, 2004), an improved knowledge of this pathway might help our understanding of how plants cope with abiotic stresses. Finally, as the CoA biosynthetic pathway is evolutionarily conserved, its study in plants might have clinical relevance, as defects in this pathway lead to a human neurodegenerative disease (Zhou et al, 2001).…”

mentioning

confidence: 99%

“…HAL3A is a flavoprotein that catalyzes the decarboxylation of PPC to 4#-phosphopantetheine (Kupke et al, 2001;HernandezAcosta et al, 2002), and overexpression of this enzyme leads to improved plant tolerance to salt and osmotic stress (Espinosa-Ruiz et al, 1999;Yonamine et al, 2004). Two highly homologous genes, HAL3A (At3g18030) and HAL3B (At1g48605), are present in the Arabidopsis genome.…”

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confidence: 99%

An Arabidopsis Mutant Impaired in Coenzyme A Biosynthesis Is Sugar Dependent for Seedling Establishment

et al. 2006

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Once the plant coenzyme A (CoA) biosynthetic pathway has been elucidated by comparative genomics, it is feasible to analyze the physiological relevance of CoA biosynthesis in plant life. To this end, we have identified and characterized Arabidopsis (Arabidopsis thaliana) T-DNA knockout mutants of two CoA biosynthetic genes, HAL3A and HAL3B. The HAL3A gene encodes a 4#-phosphopantothenoyl-cysteine decarboxilase that generates 4#-phosphopantetheine. A second gene, HAL3B, whose gene product is 86% identical to that of HAL3A, is present in the Arabidopsis genome. HAL3A appears to have a predominant role over HAL3B according to their respective mRNA expression levels. The hal3a-1, hal3a-2, and hal3b mutants were viable and showed a similar growth rate as that in wild-type plants; in contrast, a hal3a-1 hal3b double mutant was embryo lethal. Unexpectedly, seedlings that were null for HAL3A and heterozygous for HAL3B (aaBb genotype) displayed a sucrose (Suc)-dependent phenotype for seedling establishment, which is in common with mutants defective in b-oxidation. This phenotype was genetically complemented in aaBB siblings of the progeny and chemically complemented by pantethine. In contrast, seedling establishment of Aabb plants was not Suc dependent, proving a predominant role of HAL3A over HAL3B at this stage. Total fatty acid and acyl-CoA measurements of 5-d-old aaBb seedlings in medium lacking Suc revealed stalled storage lipid catabolism and impaired CoA biosynthesis; in particular, acetyl-CoA levels were reduced by approximately 80%. Taken together, these results provide in vivo evidence for the function of HAL3A and HAL3B, and they point out the critical role of CoA biosynthesis during early postgerminative growth.

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Arabidopsis thaliana AtHAL3: a flavoprotein related to salt and osmotic tolerance and plant growth

Cited by 159 publications

References 39 publications

Does Abiotic Stress Cause Functional B Vitamin Deficiency in Plants?

Does Abiotic Stress Cause Functional B Vitamin Deficiency in Plants?

The Coenzyme A Biosynthetic Enzyme Phosphopantetheine Adenylyltransferase Plays a Crucial Role in Plant Growth, Salt/Osmotic Stress Resistance, and Seed Lipid Storage

An Arabidopsis Mutant Impaired in Coenzyme A Biosynthesis Is Sugar Dependent for Seedling Establishment

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