A5018156800- Plant nutrient uptake and metabolism
- Food composition and properties
- Enzyme Production and Characterization
- Plant Molecular Biology Research
- Phytase and its Applications
- Genetic Mapping and Diversity in Plants and Animals
- Photosynthetic Processes and Mechanisms
- Plant Reproductive Biology
- Polysaccharides and Plant Cell Walls
- Soybean genetics and cultivation
- Biofuel production and bioconversion
- Chromosomal and Genetic Variations
- Protein Tyrosine Phosphatases
- Glycogen Storage Diseases and Myoclonus
- Plant Stress Responses and Tolerance
- Plant-Microbe Interactions and Immunity
- Lysosomal Storage Disorders Research
- Plant responses to water stress
- Microbial Metabolites in Food Biotechnology
- Plant Gene Expression Analysis
- Plant biochemistry and biosynthesis
- Heat shock proteins research
- Microbial metabolism and enzyme function
- Animal Genetics and Reproduction
- Ubiquitin and proteasome pathways
Institute of Molecular Biology, Academia Sinica
2003-2022
Academia Sinica
1996-2014
National Chung Hsing University
2010-2012
National Taipei University
2010-2012
Institute of Plant and Microbial Biology, Academia Sinica
2009
National Defense Medical Center
2009
National Taiwan University
2009
Sainsbury Laboratory
2009
Norwich Research Park
2009
John Innes Centre
2004-2009
A previously unknown maltose transporter is essential for the conversion of starch to sucrose in Arabidopsis leaves at night. The was identified by isolating two allelic mutants with high levels and very maltose, an intermediate breakdown. mutations affect a gene function, MEX1 . We show that MEX1is unrelated other sugar transporters. severe mex1 phenotype demonstrates predominant route carbohydrate export from chloroplasts Homologous genes plants including rice potato indicate widespread...
The function of DNA methylation in higher plants was investigated by expression a complementary encoding cytosine methyltransferase (MET1) from Arabidopsis thaliana as an antisense RNA transgenic plants. This resulted 34 to 71 percent reduction total genomic methylation. Loss observed both repetitive and single-copy gene sequences. Developmental effects included altered heterochrony, changes meristem identity organ number, female sterility. Cytosine demethylation prolonged vegetative...
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...
Summary Maltose is exported from the Arabidopsis chloroplast as main product of starch degradation at night. To investigate its fate in cytosol, we characterised plants with mutations a gene encoding putative glucanotransferase (disproportionating enzyme; DPE2), protein similar to maltase Q (MalQ) involved maltose metabolism bacteria. Use DPE2 antiserum revealed that cytosolic. Four independent mutant lines lacked this and displayed decreased capacity for both synthesis leaves. They...
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...
Abstract Starch is the major storage carbohydrate in plants. It comprised of glucans that form semicrystalline granules. Glucan phosphorylation a prerequisite for normal starch breakdown, but phosphoglucan metabolism not understood. A putative protein phosphatase encoded at Excess 4 (SEX4) locus Arabidopsis thaliana was recently shown to be required breakdown. Here, we show SEX4 vivo and define its role within degradation pathway. dephosphorylates both granule surface soluble phosphoglucans...
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....
Summary Floral initiation is orchestrated by systemic floral activators and inhibitors. This remote‐control system may integrate environmental cues to modulate initiation. Recently, FLOWERING LOCUS T (FT) was found be a florigen. However, the identity of inhibitor or anti‐florigen remains elucidated. Here we show that Arabidopsis thaliana CENTRORADIALIS homologue ( ATC ), an FT homologue, act in non‐cell autonomous manner inhibit Analysis null mutant revealed short‐day‐induced inhibitor....
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...
ABSTRACT We have analyzed donor and target sites of the mobile element Activator (Ac) that are altered as a result somatic transposition from P locus in maize. Previous genetic analysis has indicated two mitotic daughter lineages which Ac differ their constitution at locus. Both lineages, however, usually contain transposed elements map to same position. Using methylation-sensitive restriction enzymes genomic blot analysis, we identified both used this assay clone identify elements. Daughter...
Abstract A putative phosphatase, LSF1 (for LIKE SEX4; previously PTPKIS2), is closely related in sequence and structure to STARCH-EXCESS4 (SEX4), an enzyme necessary for the removal of phosphate groups from starch polymers during degradation Arabidopsis (Arabidopsis thaliana) leaves at night. We show that also required degradation: lsf1 mutants, like sex4 have substantially more their than wild-type plants throughout diurnal cycle. chloroplastic located on surface granules. mutants similar,...
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...
We evaluated the application of gas chromatography-mass spectrometry metabolic fingerprinting to classify forward genetic mutants with similar phenotypes. Mutations affecting distinct or signaling pathways can result in common phenotypic traits that are used identify screens. Measurement a broad range metabolites provides information about underlying processes affected such mutants. Metabolite profiles Arabidopsis (Arabidopsis thaliana) defective starch metabolism and uncharacterized...
• Sumoylation, a post-translational modification, has important functions in both animals and plants. However, the biological function of SUMO E3 ligase, SIZ1, rice (Oryza sativa) is still under investigation. In this study, we employed two different genetic approaches, use siz1 T-DNA mutant SIZ1-RNAi transgenic plants, to characterize SIZ1. Genetic results revealed co-segregation single insertional recessive mutation with observed phenotypes siz1. addition showing reduced plant height,...
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...
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...
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...
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....
Tiller initiation and panicle development are important agronomical traits for grain production in Oryza sativa L. (rice), but their regulatory mechanisms not yet fully understood. In this study, T-DNA mutant RNAi transgenic approaches were used to functionally characterize a unique rice gene, LAGGING GROWTH AND DEVELOPMENT 1 (LGD1). The lgd1 showed slow growth, reduced tiller number plant height, altered architecture yield. fewer unelongated internodes cells led respective reductions...