A5043567254- Plant nutrient uptake and metabolism
- Enzyme Production and Characterization
- Food composition and properties
- Phytase and its Applications
- Plant Molecular Biology Research
- Photosynthetic Processes and Mechanisms
- Microbial Metabolites in Food Biotechnology
- Plant responses to water stress
- Plant Stress Responses and Tolerance
- Plant Micronutrient Interactions and Effects
- Plant Reproductive Biology
- Protein Tyrosine Phosphatases
- Aluminum toxicity and tolerance in plants and animals
- Biofuel production and bioconversion
- Polysaccharides and Plant Cell Walls
- Glycogen Storage Diseases and Myoclonus
- Glycosylation and Glycoproteins Research
- Biochemical and Molecular Research
- Plant Physiology and Cultivation Studies
- Lysosomal Storage Disorders Research
- Soybean genetics and cultivation
- Cassava research and cyanide
Institute of Molecular Biology, Academia Sinica
1996-2022
Academia Sinica
2014
Institute of Plant and Microbial Biology, Academia Sinica
2009
National Defense Medical Center
2009
National Taiwan University
2009
Starch is the major storage carbohydrate in higher plants and of considerable importance for human diet numerous technical applications. In addition, starch can be accumulated transiently chloroplasts as a temporary deposit carbohydrates during ongoing photosynthesis. This transitory has to mobilized subsequent dark period. Mutants defective mobilization are characterized by high contents leaves after prolonged periods darkness therefore termed excess (sex) mutants. Here we describe...
In this study, our goal was to evaluate the role of starch debranching enzymes in determination structure amylopectin. We screened mutant populations Arabidopsis for plants with alterations leaf by using iodine staining. The leaves two lines stained reddish brown, whereas wild-type brownish black, indicating that a more highly branched polyglucan than amylopectin present. mutants were allelic, and mutation mapped position 18.8 on chromosome 1. One line lacked transcript gene sequence...
The Arabidopsis thaliana genome encodes three α-amylase-like proteins (AtAMY1, AtAMY2, and AtAMY3). Only AtAMY3 has a predicted N-terminal transit peptide for plastidial localization. is an unusually large α-amylase (93.5 kDa) with the C-terminal half showing similarity to other known α-amylases. When expressed in Escherichia coli, both whole protein alone show activity. We that localized chloroplasts. starch-excess mutant of sex4, previously shown have reduced activity, deficient protein....
Abstract We isolated pgi1-1, an Arabidopsis mutant with a decreased plastid phospho-glucose (Glc) isomerase activity. Whilepgi1-1 has deficiency in leaf starch synthesis, it accumulates root cap cells. It been shown that transporter for hexose phosphate transports cytosolic Glc-6-P into plastids and expresses restricted mainly to the heterotrophic tissues. The content leaves of thepgi1-1 indicates cannot be efficiently transported chloroplasts complement mutant's chloroplastic phospho-Glc...
We report that protein phosphorylation is involved in the control of starch metabolism Arabidopsis leaves at night. sex4 (starch excess 4) mutants, which have strongly reduced rates metabolism, lack a predicted to be dual specificity phosphatase. shown this chloroplastic and can bind glucans presented evidence it acts regulate initial steps degradation granule surface. Remarkably, most closely related SEX4 outside plant kingdom laforin, glucan-binding phosphatase required for mammalian...
A recessive Arabidopsis mutation, carbohydrate accumulation mutant1 (cam1), which maps to position 22.8 on chromosome 3, was identified by screening leaves of ethyl methanesulfonate-mutagenized M2 plants stained with iodine for altered starch content. Increased content in the cam1 mutant observed at onset flowering. This also had a delayed floral initiation phenotype more rosette than parental line. In addition, activities several enzymes associated metabolism were mutant. The late-flowering...
In illuminated chloroplasts, one mechanism involved in reduction-oxidation (redox) homeostasis is the malate-oxaloacetate (OAA) shuttle. Excess electrons from photosynthetic electron transport form of nicotinamide adenine dinucleotide phosphate, reduced are used by NADP-dependent malate dehydrogenase (MDH) to reduce OAA malate, thus regenerating acceptor NADP. NADP-MDH a strictly redox-regulated, light-activated enzyme that inactive dark. dark or nonphotosynthetic tissues, malate-OAA shuttle...
Starch synthesis and degradation require the participation of many enzymes, occur in both photosynthetic nonphotosynthetic tissues, are subject to environmental developmental regulation. We examine distribution starch vegetative tissues Arabidopsis (Arabidopsis thaliana) expression genes encoding core enzymes for synthesis. is accumulated plastids epidermal, mesophyll, vascular, root cap cells but not proper cells. also identify that can synthesize heterotrophically albino mutants. leaves...
Two mutants of Arabidopsis have been isolated that affect ADPG pyrophosphorylase (ADGase) activity. Previously, it has shown ADG2 encodes the large subunit ADGase. This study characterizes adg1 mutant phenotype and ADG1 gene structure. RNA blot analyses indicate adg1-1 accumulates transcripts encoding both small subunits ADGase, while adg1-2 only transcripts. RFLP analysis complementation with ADGase demonstrate subunit. Sequence indicates represents a missense mutation within gene. Western...
In Arabidopsis (Arabidopsis thaliana) leaves, starch is synthesized during the day and degraded at night to fuel growth metabolism. Starch primarily by β-amylases, liberating maltose, but this activity preceded glucan phosphorylation accompanied dephosphorylation. A phosphatase family member, LIKE SEX4 1 (LSF1), binds required for normal degradation, its exact role unclear. Here, we show that LSF1 does not dephosphorylate glucans. The recombinant dual specificity (DSP) domain of had no...
Arabidopsis mutants affecting ADPG pyrophosphorylase (ADGase) activity can be divided into two complementation groups, adg1 and adg2 . Previous biochemical studies of adg2‐1 mutant indicated that plants do not accumulate ADGase large subunit protein small subunits assemble as homotetramers. This suggested the ADG2 gene may encode ADGase. In this paper, it is shown near wild‐type levels transcripts encoding both However, by RFLP analysis with gene, we show does represent a mutation gene....
Phosphoglucose isomerase (PGI) catalyzes the interconversion of fructose-6-phosphate and glucose-6-phosphate, which impacts cell carbon metabolic flow. Arabidopsis (Arabidopsis thaliana) contains two nuclear PGI genes respectively encoding plastidial PGI1 cytosolic (cPGI). The loss impairs conversion F6P Calvin-Benson cycle to G6P for synthesis transitory starch in leaf chloroplasts. Since cpgi knockout mutants have not yet been obtained, they are thought be lethal. lethality can rescued by...