Claim · model-written summary
Oxaloacetate stimulated formation of starch-breakdown transport metabolites.
- Taxon
- spinach
Spinacia oleraceae2 - Treatment
- oxaloacetatee0
- Outcome
- dihydroxyacetone phosphate and 3-phosphoglyceratee1
- Direction
- stimulatede0
Not reportedMaterialGeneCompoundOrgan / stageInteractorInteractor roleSecond interactorSecond interactor roleComparatorSettingValueQualifier
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Formation of these compounds from starch was stimulated by ATP or oxaloacetate.”
e1“The principal products of starch breakdown in the presence of phosphate were the transport metabolites dihydroxyacetone phosphate and 3-phosphoglycerate.”
e2“isolated spinach chloroplasts”
Title
Hans W. Heldt; Chong Ja Chon; Dorothea Maronde; et al. PLANT PHYSIOLOGY 1977. doi:10.1104/pp.59.6.1146
Other claims from this paper (19)
- Intervention effect Phosphate starvation or treatments lowering cytoplasmic orthophosphate increased leaf starch synthesis.
- Observation Usually less than 30% of fixed carbon entered starch in spinach, spinach beet and tobacco leaves.
- Observation Starch formation from CO2 in isolated spinach chloroplasts was usually less than in leaves.
- Intervention effect Low phosphate nearly completely inhibited starch synthesis without substantial 3-phosphoglycerate.
- Intervention effect 3-phosphoglycerate overcame phosphate inhibition of starch synthesis.
- Mechanism The phosphoglycerate to orthophosphate ratio appeared to control starch synthesis rather than stromal hexose monophosphate.
- Mechanism Control was suggested to operate through the phosphate translocator and ADP-glucose pyrophosphorylase regulation.
- Intervention effect Dihydroxyacetone phosphate favored starch synthesis.
- Intervention effect High light favored starch synthesis.
- Intervention effect High temperature favored starch synthesis.
- Intervention effect Oxygen inhibited starch synthesis, possibly through carbon drain into glycolate.
- Intervention effect Added glucose did not promote starch formation by intact chloroplasts.
- Intervention effect Added glucose 6-phosphate did not promote starch formation by intact chloroplasts.
- Intervention effect Orthophosphate promoted starch mobilization in the dark.
- Intervention effect Phosphoglycerate inhibited phosphate-dependent starch mobilization.
- Observation Phosphate-dependent starch breakdown chiefly produced dihydroxyacetone phosphate and 3-phosphoglycerate.
- Intervention effect ATP stimulated formation of starch-breakdown transport metabolites.
- Observation Starch also converted to maltose and glucose through a phosphate-independent reaction.
- Observation Phosphate-dependent phosphorolysis degraded starch much faster than starch hydrolysis.