Maltose is the major form of carbon exported from the chloroplast at night

@article{Weise2004MaltoseIT,
  title={Maltose is the major form of carbon exported from the chloroplast at night},
  author={Sean E. Weise and Andreas P. M. Weber and Thomas David Sharkey},
  journal={Planta},
  year={2004},
  volume={218},
  pages={474-482}
}
Transitory starch is formed in chloroplasts during the day and broken down at night. We investigated carbon export from chloroplasts resulting from transitory-starch breakdown. Starch-filled chloroplasts from spinach (Spinacia oleracea L. cv. Nordic IV) were isolated 1 h after the beginning of the dark period and incubated for 2.5 h, followed by centrifugation through silicone oil. Exported products were measured in the incubation medium to avoid measuring compounds retained inside the… 

The role of amylomaltase in maltose metabolism in the cytosol of photosynthetic cells

Results show that Arabidopsis has an amylomaltase that is involved in the conversion of maltose to sucrose in the cytosol, and it is proposed that maltose metabolism in the cytoplasm of Arabidoptera leaves is similar to that in the Cytosol of E. coli.

Blocking the Metabolism of Starch Breakdown Products in Arabidopsis Leaves Triggers Chloroplast Degradation

It is proposed that the accumulation of maltose and malto-oligosaccharides causes chloroplast dysfunction, which may by signaled via a form of retrograde signaling and trigger chloropleft degradation.

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It is hypothesized that maltose metabolism is a bridge between transitory starch breakdown and the plants' adaptation to changes in environmental conditions, and could provide a mechanism for adjusting starch breakdown rates to day length.

b -Maltose Is the Metabolically Active Anomer of Maltose during Transitory Starch Degradation 1[w]

Maltose is the major form of carbon exported from the chloroplast at night as a result of transitory starch breakdown. Maltose exists as an a - or b -anomer. We developed an enzymatic technique for

Carbon Balance and Circadian Regulation of Hydrolytic and Phosphorolytic Breakdown of Transitory Starch1

Maltose was increased under photorespiratory conditions in both wild type and plants lacking starch phosphorylase, indicating that regulation of starch breakdown may occur at a point preceding the division of the hydrolytic and phosphorolytic pathways.

β-Maltose Is the Metabolically Active Anomer of Maltose during Transitory Starch Degradation1[w]

It is concluded that β-maltose is the metabolically active anomer of maltose and that a sufficient gradient of β-Maltose exists between the chloroplast and cytosol to allow for passive transport of Maltose out of chloroplasts at night.

The diurnal metabolism of leaf starch.

The present review provides an overview of starch biosynthesis, starch structure and starch degradation in the leaves of plants, focusing on recent advances in each area and highlighting outstanding questions.

A transglucosidase necessary for starch degradation and maltose metabolism in leaves at night acts on cytosolic heteroglycans (SHG).

Evidence is presented that DPE2 acts on the recently identified cytosolic water-soluble heteroglycans (SHG) as does the cytOSolic phosphorylase (EC 2.4.1.1) isoform, and in vitro two-step (14)C labeling assays are demonstrated that the two transferases can utilize the same acceptor sites of the SHG.

Daylength and Circadian Effects on Starch Degradation and Maltose Metabolism1

The expression of genes encoding starch degradation-related enzymes was under very strong circadian control in continuous light, and the amount of maltose showed a strong endogenous rhythm close to 24 h, indicating that maltose metabolism is under circadian control.

Feedback Inhibition of Starch Degradation in Arabidopsis Leaves Mediated by Trehalose 6-Phosphate1[W][OPEN]

It is proposed that Tre6P is a component in a signaling pathway that mediates the feedback regulation of starch breakdown by sucrose, potentially linking starch turnover to demand for sucrose by growing sink organs at night.
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