Betaine aldehyde dehydrogenase genes from Arabidopsis with different sub-cellular localization affect stress responses

Abstract

Arabidopsis thaliana belongs to those plants that do not naturally accumulate glycine betaine (GB), although its genome contains two genes, ALDH10A8 and ALDH10A9 that code for betaine aldehyde dehydrogenases (BADHs). BADHs were initially known to catalyze the last step of the biosynthesis of GB in plants. But they can also oxidize metabolism-derived aminoaldehydes to their corresponding amino acids in some cases. This study was carried out to investigate the functional properties of Arabidopsis BADH genes. Here, we have shown that ALDH10A8 and ALDH10A9 proteins are targeted to leucoplasts and peroxisomes, respectively. The expression patterns of ALDH10A8 and ALDH10A9 genes have been analysed under abiotic stress conditions. Both genes are expressed in the plant and weakly induced by ABA, salt, chilling (4°C), methyl viologen and dehydration. The role of the ALDH10A8 gene was analysed using T-DNA insertion mutants. There was no phenotypic difference between wild-type and mutant plants in the absence of stress. But ALDH10A8 seedlings and 4-week-old plants were more sensitive to dehydration and salt stress than wild-type plants. The recombinant ALDH10A9 enzyme was shown to oxidize betaine aldehyde, 4-aminobutyraldehyde and 3-aminopropionaldehyde to their corresponding carboxylic acids. We hypothesize that ALDH10A8 or ALDH10A9 may serve as detoxification enzymes controlling the level of aminoaldehydes, which are produced in cellular metabolism under stress conditions.

Cloning and characterization of a novel betaine aldehyde dehydrogenase gene from Suaeda corniculata

“…The results showed that ScBADH transcripts could be induced by ABA, PEG, and especially, NaCl treatments. These results are similar to those obtained in rice but different to those obtained in Arabidopsis (Niu et al, 2007;Missihoun et al, 2011), indicating that ScBADH may be involved in signal transduction in response to salt in S. corniculata. Missihoun et al (2011) showed that young and adult plants lacking ALDH10A8 transcripts were drought and salt sensitive.…”

“…These results are similar to those obtained in rice but different to those obtained in Arabidopsis (Niu et al, 2007;Missihoun et al, 2011), indicating that ScBADH may be involved in signal transduction in response to salt in S. corniculata. Missihoun et al (2011) showed that young and adult plants lacking ALDH10A8 transcripts were drought and salt sensitive. Similar results were found in sweet potato, in which those expressing spinach BADH had improved stress tolerance (Fan et al, 2012).…”

Amino Acid Residues Critical for the Specificity for Betaine Aldehyde of the Plant ALDH10 Isoenzyme Involved in the Synthesis of Glycine Betaine

“…On the other hand, some low-BALaffinity isoenzymes lack the peroxisomal signal. They may be located in leucoplasts, as was recently found for one of the two low-BAL-affinity isoenzymes from Arabidopsis (Missihoun et al, 2011). The rest of the low-BAL-affinity isoenzymes have an SKL or SKL-like C-terminal tripeptide.…”

Plant Peroxisomes: Biogenesis and Function

“…The physiological functions of a number of enzymes and metabolic pathways indicated by proteomic data have been verified. Examples include the oxidative pentose phosphate pathway (Meyer et al, 2011), betaine aldehyde dehydrogenase (Missihoun et al, 2011), SDRa (Wiszniewski et al, 2009), and the bifunctional transthyretin-like protein involved in purine catabolism and S-allantoin biosynthesis (Lamberto et al, 2010), which have significantly broadened our knowledge of peroxisome metabolism.…”