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Leaves of the Arabidopsis maltose exporter1 mutant exhibit a metabolic profile with features of cold acclimation in the warm.

Purdy SJ, Bussell JD, Nunn CP, Smith SM - PLoS ONE (2013)

Bottom Line: Grown at 21 °C, mex1-1 plants were much smaller, with fewer leaves, and elevated carbohydrates and amino acids compared to WT.After prolonged growth at 4 °C, the shoot biomass, rosette diameter and number of leaves at bolting were similar in mex1-1 and WT.This may in turn compromise growth of mex1-1 in the warm relative to WT.

View Article: PubMed Central - PubMed

Affiliation: Australian Research Council Centre of Excellence in Plant Energy Biology, The University of Western Australia, Perth, Western Australia, Australia ; Institute of Biological, Environmental & Rural Sciences, Aberystwyth University, Aberystwyth, United Kingdom.

ABSTRACT

Background: Arabidopsis plants accumulate maltose from starch breakdown during cold acclimation. The Arabidopsis mutant, maltose excess1-1, accumulates large amounts of maltose in the plastid even in the warm, due to a deficient plastid envelope maltose transporter. We therefore investigated whether the elevated maltose level in mex1-1 in the warm could result in changes in metabolism and physiology typical of WT plants grown in the cold.

Principal findings: Grown at 21 °C, mex1-1 plants were much smaller, with fewer leaves, and elevated carbohydrates and amino acids compared to WT. However, after transfer to 4 °C the total soluble sugar pool and amino acid concentration was in equal abundance in both genotypes, although the most abundant sugar in mex1-1 was still maltose whereas sucrose was in greatest abundance in WT. The chlorophyll a/b ratio in WT was much lower in the cold than in the warm, but in mex1-1 it was low in both warm and cold. After prolonged growth at 4 °C, the shoot biomass, rosette diameter and number of leaves at bolting were similar in mex1-1 and WT.

Conclusions: The mex1-1 mutation in warm-grown plants confers aspects of cold acclimation, including elevated levels of sugars and amino acids and low chlorophyll a/b ratio. This may in turn compromise growth of mex1-1 in the warm relative to WT. We suggest that elevated maltose in the plastid could be responsible for key aspects of cold acclimation.

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Related in: MedlinePlus

Total anthocyanin content in Col-0 and mex1-1 when grown to bolting at 21 °C or 4 °C.Data is the mean of five biological replicates ± SE. Different letters show significant differences (Student’s T-Test P ≤ 0.05).
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pone-0079412-g005: Total anthocyanin content in Col-0 and mex1-1 when grown to bolting at 21 °C or 4 °C.Data is the mean of five biological replicates ± SE. Different letters show significant differences (Student’s T-Test P ≤ 0.05).

Mentions: The anthocyanin content of the WT was 26-fold higher after growth at 4 °C while the content in mex1-1 was low in both treatments (Figure 5). Accumulation of anthocyanins in response to cold is a common response in plants and presumably provides an adaptive advantage [27]. Thus mex1-1 would appear to be deficient in this aspect of the response to cold.


Leaves of the Arabidopsis maltose exporter1 mutant exhibit a metabolic profile with features of cold acclimation in the warm.

Purdy SJ, Bussell JD, Nunn CP, Smith SM - PLoS ONE (2013)

Total anthocyanin content in Col-0 and mex1-1 when grown to bolting at 21 °C or 4 °C.Data is the mean of five biological replicates ± SE. Different letters show significant differences (Student’s T-Test P ≤ 0.05).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3818174&req=5

pone-0079412-g005: Total anthocyanin content in Col-0 and mex1-1 when grown to bolting at 21 °C or 4 °C.Data is the mean of five biological replicates ± SE. Different letters show significant differences (Student’s T-Test P ≤ 0.05).
Mentions: The anthocyanin content of the WT was 26-fold higher after growth at 4 °C while the content in mex1-1 was low in both treatments (Figure 5). Accumulation of anthocyanins in response to cold is a common response in plants and presumably provides an adaptive advantage [27]. Thus mex1-1 would appear to be deficient in this aspect of the response to cold.

Bottom Line: Grown at 21 °C, mex1-1 plants were much smaller, with fewer leaves, and elevated carbohydrates and amino acids compared to WT.After prolonged growth at 4 °C, the shoot biomass, rosette diameter and number of leaves at bolting were similar in mex1-1 and WT.This may in turn compromise growth of mex1-1 in the warm relative to WT.

View Article: PubMed Central - PubMed

Affiliation: Australian Research Council Centre of Excellence in Plant Energy Biology, The University of Western Australia, Perth, Western Australia, Australia ; Institute of Biological, Environmental & Rural Sciences, Aberystwyth University, Aberystwyth, United Kingdom.

ABSTRACT

Background: Arabidopsis plants accumulate maltose from starch breakdown during cold acclimation. The Arabidopsis mutant, maltose excess1-1, accumulates large amounts of maltose in the plastid even in the warm, due to a deficient plastid envelope maltose transporter. We therefore investigated whether the elevated maltose level in mex1-1 in the warm could result in changes in metabolism and physiology typical of WT plants grown in the cold.

Principal findings: Grown at 21 °C, mex1-1 plants were much smaller, with fewer leaves, and elevated carbohydrates and amino acids compared to WT. However, after transfer to 4 °C the total soluble sugar pool and amino acid concentration was in equal abundance in both genotypes, although the most abundant sugar in mex1-1 was still maltose whereas sucrose was in greatest abundance in WT. The chlorophyll a/b ratio in WT was much lower in the cold than in the warm, but in mex1-1 it was low in both warm and cold. After prolonged growth at 4 °C, the shoot biomass, rosette diameter and number of leaves at bolting were similar in mex1-1 and WT.

Conclusions: The mex1-1 mutation in warm-grown plants confers aspects of cold acclimation, including elevated levels of sugars and amino acids and low chlorophyll a/b ratio. This may in turn compromise growth of mex1-1 in the warm relative to WT. We suggest that elevated maltose in the plastid could be responsible for key aspects of cold acclimation.

Show MeSH
Related in: MedlinePlus