Analysis of Starch Metabolism in Chloroplasts

Hostettler, Carmen; Kölling, Katharina; Santelia, Diana; Streb, Sebastian; Kötting, Oliver; Zeeman, Samuel C.

doi:10.1007/978-1-61779-237-3_21

Cited by 60 publications

(63 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Rosettes from plants grown in hydroponic culture or in soil were harvested into liquid N 2 and extracted in 0.7 M perchloric acid as previously described (Hostettler et al, 2011). Starch in the insoluble fraction was determined by measuring the amount of glucose released by treatment with a-amylase and amyloglucosidase (both from Roche).…”

Section: Quantification Of Starch and Leaf Soluble Sugarsmentioning

confidence: 99%

Regulation of Leaf Starch Degradation by Abscisic Acid Is Important for Osmotic Stress Tolerance in Plants

et al. 2016

Self Cite

View full text Add to dashboard Cite

Starch serves functions that range over a timescale of minutes to years, according to the cell type from which it is derived. In guard cells, starch is rapidly mobilized by the synergistic action of b-AMYLASE1 (BAM1) and a-AMYLASE3 (AMY3) to promote stomatal opening. In the leaves, starch typically accumulates gradually during the day and is degraded at night by BAM3 to support heterotrophic metabolism. During osmotic stress, starch is degraded in the light by stress-activated BAM1 to release sugar and sugar-derived osmolytes. Here, we report that AMY3 is also involved in stress-induced starch degradation. Recently isolated Arabidopsis thaliana amy3 bam1 double mutants are hypersensitive to osmotic stress, showing impaired root growth. amy3 bam1 plants close their stomata under osmotic stress at similar rates as the wild type but fail to mobilize starch in the leaves. 14 C labeling showed that amy3 bam1 plants have reduced carbon export to the root, affecting osmolyte accumulation and root growth during stress. Using genetic approaches, we further demonstrate that abscisic acid controls the activity of BAM1 and AMY3 in leaves under osmotic stress through the AREB/ABF-SnRK2 kinase-signaling pathway. We propose that differential regulation and isoform subfunctionalization define starch-adaptive plasticity, ensuring an optimal carbon supply for continued growth under an ever-changing environment.

show abstract

Section: Quantification Of Starch and Leaf Soluble Sugarsmentioning

confidence: 99%

Regulation of Leaf Starch Degradation by Abscisic Acid Is Important for Osmotic Stress Tolerance in Plants

et al. 2016

Self Cite

View full text Add to dashboard Cite

show abstract

“…The insoluble fraction contained starch and was washed once with cold water, four times with 70% (v/v) ethanol, and resuspended in 1 mL water. Starch was quantified in the insoluble fraction as described in Hostettler et al (2011).…”

Section: Starch Measurementmentioning

confidence: 99%

Distinct Functions of STARCH SYNTHASE 4 Domains in Starch Granule Formation

Pfister

Jenny

et al. 2017

Plant Physiol.

Self Cite

View full text Add to dashboard Cite

The formation of normal starch granules in Arabidopsis (Arabidopsis thaliana) leaf chloroplasts requires STARCH SYNTHASE 4 (SS4). In plants lacking SS4, chloroplasts typically produce only one round granule rather than multiple lenticular granules. The mechanisms by which SS4 determines granule number and morphology are not understood. The N-terminal region of SS4 is unique among SS isoforms and contains several long coiled-coil motifs, typically implicated in protein-protein interactions. The C-terminal region contains the catalytic glucosyltransferase domains, which are widely conserved in plant SS and bacterial glycogen synthase (GS) isoforms. We investigated the specific roles of the N-and C-terminal regions of SS4 by expressing truncated versions of SS4 and a fusion between the N-terminal region of SS4 and GS in the Arabidopsis ss4 mutant. Expression of the N-terminal region of SS4 alone did not alter the ss4 mutant phenotype. Expression of the C-terminal region of SS4 alone increased granule initiation but did not rescue their aberrant round morphology. Expression of a self-priming GS from Agrobacterium tumefaciens also increased the number of round granules. Remarkably, fusion of the N-terminal region of SS4 to A. tumefaciens GS restored the development of wild-type-like lenticular starch granules. Interestingly, the N-terminal region of SS4 alone or when fused to GS conferred a patchy subchloroplastic localization similar to that of the full-length SS4 protein. Considered together, these data suggest that, while the glucosyltransferase activity of SS4 is important for granule initiation, the N-terminal part of SS4 serves to establish the correct granule morphology by properly localizing this activity.

show abstract

“…Sepals, stamens, and carpels were harvested into liquid N 2 and extracted in 200 mL of 0.7 M perchloric acid as described (Hostettler et al, 2011). Starch in the insoluble fraction was resuspended in 195 mL of 0.22 M sodium acetate, pH 4.8, and determined by measuring the amount of Glc released by treatment with a-amylase (Roche) and amyloglucosidase (Roche) as described (Hostettler et al, 2011).…”

Section: Starch Quantificationmentioning

confidence: 99%

Starch Turnover and Metabolism during Flower and Early Embryo Development

et al. 2016

Self Cite

View full text Add to dashboard Cite

ORCID IDs: 0000-0002-4761-3731 (A.H.); 0000-0002-6552-4708 (H.V.); 0000-0001-9554-5318 (M.W.S.); 0000-0001-9686-1216 (D.S.); 0000-0002-0522-8974 (U.G.).The accumulation of starch within photosynthetic tissues and within dedicated storage organs has been characterized extensively in many species, and a function in buffering carbon availability or in fueling later growth phases, respectively, has been proposed. However, developmentally regulated starch turnover within heterotrophic tissues other than dedicated storage organs is poorly characterized, and its function is not well understood. Here, we report on the characterization of starch turnover during flower, early embryo, and silique development in Arabidopsis (Arabidopsis thaliana) using a combined clearing-staining technique on whole-mount tissue. Besides the two previously documented waves of transient starch accumulation in the stamen envelope, occurring during meiosis and pollen mitosis I, we identified a novel, third wave of starch amylogenesis/amylolysis during the last stages of stamen development. To gain insights into the underlying molecular mechanisms, we analyzed publicly available microarray data, which revealed a developmentally coordinated expression of carbohydrate transport and metabolism genes during these waves of transient starch accumulation. Based on this analysis, we characterized starch dynamics in mutants affecting hexose phosphate metabolism and translocation, and identified the Glc-6-phosphate/phosphate antiporter GPT1 as the putative translocator of Glc-6-phosphate for starch biosynthesis in reproductive tissues. Based on these results, we propose a model of starch synthesis within the pollen grain and discuss the nutrient transport route feeding the embryo within the developing seed.

show abstract

Analysis of Starch Metabolism in Chloroplasts

Cited by 60 publications

References 14 publications

Regulation of Leaf Starch Degradation by Abscisic Acid Is Important for Osmotic Stress Tolerance in Plants

Regulation of Leaf Starch Degradation by Abscisic Acid Is Important for Osmotic Stress Tolerance in Plants

Distinct Functions of STARCH SYNTHASE 4 Domains in Starch Granule Formation

Starch Turnover and Metabolism during Flower and Early Embryo Development

Contact Info

Product

Resources

About