@misc{ApriyantoCompartFettke2022,
  author    = {Apriyanto, Ardha and Compart, Julia and Fettke, J{\"o}rg},
  title     = {A review of starch, a unique biopolymer - structure, metabolism and in planta modifications},
  series = {Plant science : an international journal of experimental plant biology},
  volume    = {318},
  journal   = {Plant science : an international journal of experimental plant biology},
  publisher = {Elsevier Science},
  address   = {Amsterdam [u.a.]},
  issn      = {0168-9452},
  doi       = {10.1016/j.plantsci.2022.111223},
  pages     = {8},
  year      = {2022},
  abstract  = {Starch is a complex carbohydrate polymer produced by plants and especially by crops in huge amounts. It consists of amylose and amylopectin, which have alpha-1,4-and alpha-1,6-linked glucose units. Despite this simple chemistry, the entire starch metabolism is complex, containing various (iso)enzymes/proteins. However, whose interplay is still not yet fully understood. Starch is essential for humans and animals as a source of nutrition and energy. Nowadays, starch is also commonly used in non-food industrial sectors for a variety of purposes. However, native starches do not always satisfy the needs of a wide range of (industrial) applications. This review summarizes the structural properties of starch, analytical methods for starch characterization, and in planta starch modifications.},
  language  = {en}
}
@article{LiApriyantoFloresCastellanosetal.2022,
  author    = {Li, Xiaoping and Apriyanto, Ardha and Flores Castellanos, Junio and Compart, Julia and Muntaha, Sidratul Nur and Fettke, J{\"o}rg},
  title     = {Dpe2/phs1 revealed unique starch metabolism with three distinct phases characterized by different starch granule numbers per chloroplast, allowing insights into the control mechanism of granule number regulation by gene co-regulation and metabolic profiling},
  series = {Frontiers in Plant Science},
  journal   = {Frontiers in Plant Science},
  publisher = {Frontiers},
  address   = {Lausanne, Schweiz},
  issn      = {1664-462X},
  doi       = {10.3389/fpls.2022.1039534},
  pages     = {1 -- 16},
  year      = {2022},
  abstract  = {An Arabidopsis mutant lacking both the cytosolic Disproportionating enzyme 2 (DPE2) and the plastidial glucan Phosphorylase 1 (PHS1) revealed a unique starch metabolism. Dpe2/phs1 has been reported to have only one starch granule number per chloroplast when grown under diurnal rhythm. For this study, we analyzed dpe2/phs1 in details following the mutant development, and found that it showed three distinct periods of granule numbers per chloroplast, while there was no obvious change observed in Col-0. In young plants, the starch granule number was similar to that in Col-0 at first, and then decreased significantly, down to one or no granule per chloroplast, followed by an increase in the granule number. Thus, in dpe2/phs1, control over the starch granule number is impaired, but it is not defective in starch granule initiation. The data also indicate that the granule number is not fixed, and is regulated throughout plant growth. Furthermore, the chloroplasts revealed alterations during these three periods, with a partially strong aberrant morphology in the middle phase. Interestingly, the unique metabolism was perpetuated when starch degradation was further impaired through an additional lack of Isoamylase 3 (ISA3) or Starch excess 4 (SEX4). Transcriptomic studies and metabolic profiling revealed the co-regulation of starch metabolism-related genes and a clear metabolic separation between the periods. Most senescence-induced genes were found to be up-regulated more than twice in the starch-less mature leaves. Thus, dpe2/phs1 is a unique plant material source, with which we may study starch granule number regulation to obtain a more detailed understanding.},
  language  = {en}
}
@misc{LiApriyantoFloresCastellanosetal.2022,
  author    = {Li, Xiaoping and Apriyanto, Ardha and Flores Castellanos, Junio and Compart, Julia and Muntaha, Sidratul Nur and Fettke, J{\"o}rg},
  title     = {Dpe2/phs1 revealed unique starch metabolism with three distinct phases characterized by different starch granule numbers per chloroplast, allowing insights into the control mechanism of granule number regulation by gene co-regulation and metabolic profiling},
  series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  journal   = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  number    = {1286},
  issn      = {1866-8372},
  doi       = {10.25932/publishup-57125},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-571250},
  pages     = {16},
  year      = {2022},
  abstract  = {An Arabidopsis mutant lacking both the cytosolic Disproportionating enzyme 2 (DPE2) and the plastidial glucan Phosphorylase 1 (PHS1) revealed a unique starch metabolism. Dpe2/phs1 has been reported to have only one starch granule number per chloroplast when grown under diurnal rhythm. For this study, we analyzed dpe2/phs1 in details following the mutant development, and found that it showed three distinct periods of granule numbers per chloroplast, while there was no obvious change observed in Col-0. In young plants, the starch granule number was similar to that in Col-0 at first, and then decreased significantly, down to one or no granule per chloroplast, followed by an increase in the granule number. Thus, in dpe2/phs1, control over the starch granule number is impaired, but it is not defective in starch granule initiation. The data also indicate that the granule number is not fixed, and is regulated throughout plant growth. Furthermore, the chloroplasts revealed alterations during these three periods, with a partially strong aberrant morphology in the middle phase. Interestingly, the unique metabolism was perpetuated when starch degradation was further impaired through an additional lack of Isoamylase 3 (ISA3) or Starch excess 4 (SEX4). Transcriptomic studies and metabolic profiling revealed the co-regulation of starch metabolism-related genes and a clear metabolic separation between the periods. Most senescence-induced genes were found to be up-regulated more than twice in the starch-less mature leaves. Thus, dpe2/phs1 is a unique plant material source, with which we may study starch granule number regulation to obtain a more detailed understanding.},
  language  = {en}
}
@article{MuntahaLiCompartetal.2022,
  author    = {Muntaha, Sidratul Nur and Li, Xiaoping and Compart, Julia and Apriyanto, Ardha and Fettke, J{\"o}rg},
  title     = {Carbon pathways during transitory starch degradation in Arabidopsis differentially affect the starch granule number and morphology in the dpe2/phs1 mutant background},
  series = {Plant physiology and biochemistry : an official journal of the Federation of European Societies of Plant Physiology},
  volume    = {180},
  journal   = {Plant physiology and biochemistry : an official journal of the Federation of European Societies of Plant Physiology},
  publisher = {Elsevier},
  address   = {Paris},
  issn      = {0981-9428},
  doi       = {10.1016/j.plaphy.2022.03.033},
  pages     = {35 -- 41},
  year      = {2022},
  abstract  = {The Arabidopsis knockout mutant lacking both the cytosolic disproportionating enzyme 2 (DPE2) and the plastidial phosphorylase (PHS1) had a dwarf-growth phenotype, a reduced and uneven distribution of starch within the plant rosettes, and a lower starch granule number per chloroplast under standard growth conditions. In contrast, a triple mutant impaired in starch degradation by its additional lack of the glucan, water dikinase (GWD) showed improved plant growth, a starch-excess phenotype, and a homogeneous starch distribution. Furthermore, the number of starch granules per chloroplast was increased and was similar to the wild type. We concluded that ongoing starch degradation is mainly responsible for the observed phenotype of dpe2/phs1. Next, we generated two further triple mutants lacking either the phosphoglucan, water dikinase (PWD), or the disproportionating enzyme 1 (DPE1) in the background of the double mutant. Analysis of the starch metabolism revealed that even minor ongoing starch degradation observed in dpe2/phs1/pwd maintained the double mutant phenotype. In contrast, an additional blockage in the glucose pathway of starch breakdown, as in dpe2/phs1/ dpe1, resulted in a nearly starch-free phenotype and massive chloroplast degradation. The characterized mutants were discussed in the context of starch granule formation.},
  language  = {en}
}
@article{ApriyantoCompartFettke2023,
  author    = {Apriyanto, Ardha and Compart, Julia and Fettke, J{\"o}rg},
  title     = {Transcriptomic analysis of mesocarp tissue during fruit development of the oil palm revealed specific isozymes related to starch metabolism that control oil yield},
  series = {Frontiers in plant science},
  volume    = {14},
  journal   = {Frontiers in plant science},
  publisher = {Frontiers Media},
  address   = {Lausanne},
  issn      = {1664-462X},
  doi       = {10.3389/fpls.2023.1220237},
  pages     = {13},
  year      = {2023},
  abstract  = {The oil palm (Elaeis guineensis Jacq.) produces a large amount of oil from the fruit. However, increasing the oil production in this fruit is still challenging. A recent study has shown that starch metabolism is essential for oil synthesis in fruit-producing species. Therefore, the transcriptomic analysis by RNA-seq was performed to observe gene expression alteration related to starch metabolism genes throughout the maturity stages of oil palm fruit with different oil yields. Gene expression profiles were examined with three different oil yields group (low, medium, and high) at six fruit development phases (4, 8, 12, 16, 20, and 22 weeks after pollination). We successfully identified and analyzed differentially expressed genes in oil palm mesocarps during development. The results showed that the transcriptome profile for each developmental phase was unique. Sucrose flux to the mesocarp tissue, rapid starch turnover, and high glycolytic activity have been identified as critical factors for oil production in oil palms. For starch metabolism and the glycolytic pathway, we identified specific gene expressions of enzyme isoforms (isozymes) that correlated with oil production, which may determine the oil content. This study provides valuable information for creating new high-oil-yielding palm varieties via breeding programs or genome editing approaches.},
  language  = {en}
}
@article{CompartSinghFettkeetal.2023,
  author    = {Compart, Julia and Singh, Aakanksha and Fettke, J{\"o}rg and Apriyanto, Ardha},
  title     = {Customizing starch properties},
  series = {Polymers},
  volume    = {15},
  journal   = {Polymers},
  number    = {16},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {2073-4360},
  doi       = {10.3390/polym15163491},
  pages     = {20},
  year      = {2023},
  abstract  = {Starch has been a convenient, economically important polymer with substantial applications in the food and processing industry. However, native starches present restricted applications, which hinder their industrial usage. Therefore, modification of starch is carried out to augment the positive characteristics and eliminate the limitations of the native starches. Modifications of starch can result in generating novel polymers with numerous functional and value-added properties that suit the needs of the industry. Here, we summarize the possible starch modifications in planta and outside the plant system (physical, chemical, and enzymatic) and their corresponding applications. In addition, this review will highlight the implications of each starch property adjustment.},
  language  = {en}
}
@article{ApriyantoCompartZimmermannetal.2022,
  author    = {Apriyanto, Ardha and Compart, Julia and Zimmermann, Vincent and Alseekh, Saleh and Fernie, Alisdair R. 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}
}