@article{SinghCompartALRawietal.2022, author = {Singh, Aakanksha and Compart, Julia and AL-Rawi, Shadha Abduljaleel and Mahto, Harendra and Ahmad, Abubakar Musa and Fettke, J{\"o}rg}, title = {LIKE EARLY STARVATION 1 alters the glucan structures at the starch granule surface and thereby influences the action of both starch-synthesizing and starch-degrading enzymes}, series = {The plant journal}, volume = {111}, journal = {The plant journal}, number = {3}, publisher = {Wiley-Blackwell}, address = {Oxford}, issn = {0960-7412}, doi = {10.1111/tpj.15855}, pages = {819 -- 835}, year = {2022}, abstract = {For starch metabolism to take place correctly, various enzymes and proteins acting on the starch granule surface are crucial. Recently, two non-catalytic starch-binding proteins, pivotal for normal starch turnover in Arabidopsis leaves, namely, EARLY STARVATION 1 (ESV1) and its homolog LIKE EARLY STARVATION 1 (LESV), have been identified. Both share nearly 38\% sequence homology. As ESV1 has been found to influence glucan phosphorylation via two starch-related dikinases, alpha-glucan, water dikinase (GWD) and phosphoglucan, water dikinase (PWD), through modulating the surface glucan structures of the starch granules and thus affecting starch degradation, we assess the impact of its homolog LESV on starch metabolism. Thus, the 65-kDa recombinant protein LESV and the 50-kDa ESV1 were analyzed regarding their influence on the action of GWD and PWD on the surface of the starch granules. We included starches from various sources and additionally assessed the effect of these non-enzymatic proteins on other starch-related enzymes, such as starch synthases (SSI and SSIII), starch phosphorylases (PHS1), isoamylase and beta-amylase. The data obtained indicate that starch phosphorylation, hydrolyses and synthesis were affected by LESV and ESV1. Furthermore, incubation with LESV and ESV1 together exerted an additive effect on starch phosphorylation. In addition, a stable alteration of the glucan structures at the starch granule surface following treatment with LESV and ESV1 was observed. Here, we discuss all the observed changes that point to modifications in the glucan structures at the surface of the native starch granules and present a model to explain the existing processes.}, language = {en} } @article{SchmiederNitschkeSteupetal.2013, author = {Schmieder, Peter and Nitschke, Felix and Steup, Martin and Mallow, Keven and Specker, Edgar}, title = {Determination of glucan phosphorylation using heteronuclear H-1,C-13 double and H-1,C-13,P-31 triple-resonance NMR spectra}, series = {Magnetic resonance in chemistry}, volume = {51}, journal = {Magnetic resonance in chemistry}, number = {10}, publisher = {Wiley-Blackwell}, address = {Hoboken}, issn = {0749-1581}, doi = {10.1002/mrc.3996}, pages = {655 -- 661}, year = {2013}, abstract = {Phosphorylation and dephosphorylation of starch and glycogen are important for their physicochemical properties and also their physiological functions. It is therefore desirable to reliably determine the phosphorylation sites. Heteronuclear multidimensional NMR-spectroscopy is in principle a straightforward analytical approach even for complex carbohydrate molecules. With heterogeneous samples from natural sources, however, the task becomes more difficult because a full assignment of the resonances of the carbohydrates is impossible to obtain. Here, we show that the combination of heteronuclear H-1,C-13 and H-1,C-13,P-31 techniques and information derived from spectra of a set of reference compounds can lead to an unambiguous determination of the phosphorylation sites even in heterogeneous samples.}, language = {en} } @article{MeridaFettke2021, author = {Merida, Angel and Fettke, J{\"o}rg}, title = {Starch granule initiation in Arabidopsis thaliana chloroplasts}, series = {The plant journal}, volume = {107}, journal = {The plant journal}, number = {3}, publisher = {Wiley}, address = {Hoboken}, issn = {0960-7412}, doi = {10.1111/tpj.15359}, pages = {688 -- 697}, year = {2021}, abstract = {The initiation of starch granule formation and the mechanism controlling the number of granules per plastid have been some of the most elusive aspects of starch metabolism. This review covers the advances made in the study of these processes. The analyses presented herein depict a scenario in which starch synthase isoform 4 (SS4) provides the elongating activity necessary for the initiation of starch granule formation. However, this protein does not act alone; other polypeptides are required for the initiation of an appropriate number of starch granules per chloroplast. The functions of this group of polypeptides include providing suitable substrates (maltooligosaccharides) to SS4, the localization of the starch initiation machinery to the thylakoid membranes, and facilitating the correct folding of SS4. The number of starch granules per chloroplast is tightly regulated and depends on the developmental stage of the leaves and their metabolic status. Plastidial phosphorylase (PHS1) and other enzymes play an essential role in this process since they are necessary for the synthesis of the substrates used by the initiation machinery. The mechanism of starch granule formation initiation in Arabidopsis seems to be generalizable to other plants and also to the synthesis of long-term storage starch. The latter, however, shows specific features due to the presence of more isoforms, the absence of constantly recurring starch synthesis and degradation, and the metabolic characteristics of the storage sink organs.}, language = {en} } @article{FettkeLeifelsBrustetal.2012, author = {Fettke, J{\"o}rg and Leifels, Lydia and Brust, Henrike and Herbst, Karoline and Steup, Martin}, title = {Two carbon fluxes to reserve starch in potato (Solanum tuberosum L.) tuber cells are closely interconnected but differently modulated by temperature}, series = {Journal of experimental botany}, volume = {63}, journal = {Journal of experimental botany}, number = {8}, publisher = {Oxford Univ. Press}, address = {Oxford}, issn = {0022-0957}, doi = {10.1093/jxb/ers014}, pages = {3011 -- 3029}, year = {2012}, abstract = {Parenchyma cells from tubers of Solanum tuberosum L. convert several externally supplied sugars to starch but the rates vary largely. Conversion of glucose 1-phosphate to starch is exceptionally efficient. In this communication, tuber slices were incubated with either of four solutions containing equimolar [U-C-14]glucose 1-phosphate, [U-C-14]sucrose, [U-C-14]glucose 1-phosphate plus unlabelled equimolar sucrose or [U-C-14]sucrose plus unlabelled equimolar glucose 1-phosphate. C-14-incorporation into starch was monitored. In slices from freshly harvested tubers each unlabelled compound strongly enhanced C-14 incorporation into starch indicating closely interacting paths of starch biosynthesis. However, enhancement disappeared when the tubers were stored. The two paths (and, consequently, the mutual enhancement effect) differ in temperature dependence. At lower temperatures, the glucose 1-phosphate-dependent path is functional, reaching maximal activity at approximately 20 degrees C but the flux of the sucrose-dependent route strongly increases above 20 degrees C. Results are confirmed by in vitro experiments using [U-C-14]glucose 1-phosphate or adenosine-[U-C-14]glucose and by quantitative zymograms of starch synthase or phosphorylase activity. In mutants almost completely lacking the plastidial phosphorylase isozyme(s), the glucose 1-phosphate-dependent path is largely impeded. Irrespective of the size of the granules, glucose 1-phosphate-dependent incorporation per granule surface area is essentially equal. Furthermore, within the granules no preference of distinct glucosyl acceptor sites was detectable. Thus, the path is integrated into the entire granule biosynthesis. In vitro C-14-incorporation into starch granules mediated by the recombinant plastidial phosphorylase isozyme clearly differed from the in situ results. Taken together, the data clearly demonstrate that two closely but flexibly interacting general paths of starch biosynthesis are functional in potato tuber cells.}, language = {en} } @article{DauvilleeChochoisSteupetal.2006, author = {Dauvillee, David and Chochois, Vincent and Steup, Martin and Haebel, Sophie and Eckermann, Nora and Ritte, Gerhard and Ral, Jean-Philippe and Colleoni, Christophe and Hicks, Glenn and Wattebled, Fabrice and Deschamps, Philippe and Lienard, Luc and Cournac, Laurent and Putaux, Jean-Luc and Dupeyre, Danielle and Ball, Steven G.}, title = {Plastidial phosphorylase is required for normal starch synthesis in Chlamydomonas reinhardtii}, series = {The plant journal}, volume = {48}, journal = {The plant journal}, number = {2}, publisher = {Blackwell}, address = {Oxford}, issn = {0960-7412}, doi = {10.1111/j.1365-313X.2006.02870.x}, pages = {274 -- 285}, year = {2006}, abstract = {Among the three distinct starch phosphorylase activities detected in Chlamydomonas reinhardtii, two distinct plastidial enzymes (PhoA and PhoB) are documented while a single extraplastidial form (PhoC) displays a higher affinity for glycogen as in vascular plants. The two plastidial phosphorylases are shown to function as homodimers containing two 91-kDa (PhoA) subunits and two 110-kDa (PhoB) subunits. Both lack the typical 80-amino-acid insertion found in the higher plant plastidial forms. PhoB is exquisitely sensitive to inhibition by ADP-glucose and has a low affinity for malto-oligosaccharides. PhoA is more similar to the higher plant plastidial phosphorylases: it is moderately sensitive to ADP-glucose inhibition and has a high affinity for unbranched malto-oligosaccharides. Molecular analysis establishes that STA4 encodes PhoB. Chlamydomonas reinhardtii strains carrying mutations at the STA4 locus display a significant decrease in amounts of starch during storage that correlates with the accumulation of abnormally shaped granules containing a modified amylopectin structure and a high amylose content. The wild-type phenotype could be rescued by reintroduction of the cloned wild-type genomic DNA, thereby demonstrating the involvement of phosphorylase in storage starch synthesis.}, language = {en} } @article{BrustOrzechowskiFettke2020, author = {Brust, Henrike and Orzechowski, Slawomir and Fettke, J{\"o}rg}, title = {Starch and Glycogen Analyses}, series = {Biomolecules}, volume = {10}, journal = {Biomolecules}, number = {7}, publisher = {MDPI}, address = {Basel}, issn = {2218-273X}, doi = {10.3390/biom10071020}, pages = {24}, year = {2020}, abstract = {For complex carbohydrates, such as glycogen and starch, various analytical methods and techniques exist allowing the detailed characterization of these storage carbohydrates. In this article, we give a brief overview of the most frequently used methods, techniques, and results. Furthermore, we give insights in the isolation, purification, and fragmentation of both starch and glycogen. An overview of the different structural levels of the glucans is given and the corresponding analytical techniques are discussed. Moreover, future perspectives of the analytical needs and the challenges of the currently developing scientific questions are included}, language = {en} } @article{ApriyantoCompartZimmermannetal.2022, author = {Apriyanto, Ardha and Compart, Julia and Zimmermann, Vincent and Alseekh, Saleh and Fernie, Alisdair and Fettke, J{\"o}rg}, title = {Indication that starch and sucrose are biomarkers for oil yield in oil palm (Elaeis guineensis Jacq.)}, series = {Food chemistry}, volume = {393}, journal = {Food chemistry}, publisher = {Elsevier}, address = {New York, NY [u.a.]}, issn = {0308-8146}, doi = {10.1016/j.foodchem.2022.133361}, pages = {11}, year = {2022}, abstract = {Oil palm (Elaeis guineensis Jacq.) is the most productive oil-producing crop per hectare of land. The oil that accumulates in the mesocarp tissue of the fruit is the highest observed among fruit-producing plants. A comparative analysis between high-, medium-, and low-yielding oil palms, particularly during fruit development, revealed unique characteristics. Metabolomics analysis was able to distinguish accumulation patterns defining of the various developmental stages and oil yield. Interestingly, high- and medium-yielding oil palms exhibited substantially increased sucrose levels compared to low-yielding palms. In addition, parameters such as starch granule morphology, granule size, total starch content, and starch chain length distribution (CLD) differed significantly among the oil yield categories with a clear correlation between oil yield and various starch parameters. These results provide new insights into carbohydrate and starch metabolism for biosynthesis of oil palm fruits, indicating that starch and sucrose can be used as novel, easy-to-analyze, and reliable biomarker for oil yield.}, language = {en} } @article{AnnunziataApeltCarilloetal.2017, author = {Annunziata, Maria Grazia and Apelt, Federico and Carillo, Petronia and Krause, Ursula and Feil, Regina and Mengin, Virginie and Lauxmann, Martin A. and Koehl, Karin and Nikoloski, Zoran and Stitt, Mark and Lunn, John Edward}, title = {Getting back to nature: a reality check for experiments in controlled environments}, series = {Journal of experimental botany}, volume = {68}, journal = {Journal of experimental botany}, publisher = {Oxford Univ. Press}, address = {Oxford}, issn = {0022-0957}, doi = {10.1093/jxb/erx220}, pages = {4463 -- 4477}, year = {2017}, abstract = {Irradiance from sunlight changes in a sinusoidal manner during the day, with irregular fluctuations due to clouds, and light-dark shifts at dawn and dusk are gradual. Experiments in controlled environments typically expose plants to constant irradiance during the day and abrupt light-dark transitions. To compare the effects on metabolism of sunlight versus artificial light regimes, Arabidopsis thaliana plants were grown in a naturally illuminated greenhouse around the vernal equinox, and in controlled environment chambers with a 12-h photoperiod and either constant or sinusoidal light profiles, using either white fluorescent tubes or light-emitting diodes (LEDs) tuned to a sunlight-like spectrum as the light source. Rosettes were sampled throughout a 24-h diurnal cycle for metabolite analysis. The diurnal metabolite profiles revealed that carbon and nitrogen metabolism differed significantly between sunlight and artificial light conditions. The variability of sunlight within and between days could be a factor underlying these differences. Pairwise comparisons of the artificial light sources (fluorescent versus LED) or the light profiles (constant versus sinusoidal) showed much smaller differences. The data indicate that energy-efficient LED lighting is an acceptable alternative to fluorescent lights, but results obtained from plants grown with either type of artificial lighting might not be representative of natural conditions.}, language = {en} }