@misc{CisekTokarzKontenisetal.2018,
  author    = {Cisek, Richard and Tokarz, Danielle and Kontenis, Lukas and Barzda, Virginijus and Steup, Martin},
  title     = {Polarimetric second harmonic generation microscopy},
  series = {Starch-Starke},
  volume    = {70},
  journal   = {Starch-Starke},
  number    = {1-2},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {0038-9056},
  doi       = {10.1002/star.201700031},
  pages     = {15},
  year      = {2018},
  abstract  = {Second harmonic generation (SHG) is a nonlinear optical process that inherently generates signal in non-centrosymmetric materials, such as starch granules, and therefore can be used for label-free imaging. Both intensity and polarization of SHG are determined by material properties that are characterized by the nonlinear susceptibility tensor, ((2)). Examination of the tensor is performed for each focal volume of the image by measuring the outgoing polarization state of the SHG signal for a set of incoming laser beam polarizations. Mapping of nonlinear properties expressed as the susceptibility ratio reveals structural features including the organization of crystalline material within a single starch granule, and the distribution of structural properties in a population of granules. Isolated granules, as well as in situ starch, can be analyzed using polarimetric SHG microscopy. Due to the fast sample preparation and short imaging times, polarimetric SHG microscopy allows for a quick assessment of starch structure and permits rapid feedback for bioengineering applications. This article presents the basics of SHG theory and microscopy applications for starch-containing materials. Quantification of ultrastructural features within individual starch granules is described. New results obtained by polarization resolved SHG microscopy of starch granules are presented for various maize genotypes revealing heterogeneity within a single starch particle and between various granules.},
  language  = {en}
}
@misc{CencilNitschkeSteupetal.2014,
  author    = {Cencil, Ugo and Nitschke, Felix and Steup, Martin and Minassian, Berge A. and Colleoni, Christophe and Ball, Steven G.},
  title     = {Transition from glycogen to starch metabolism in Archaeplastida},
  series = {Trends in plant science},
  volume    = {19},
  journal   = {Trends in plant science},
  number    = {1},
  publisher = {Elsevier},
  address   = {London},
  issn      = {1360-1385},
  doi       = {10.1016/j.tplants.2013.08.004},
  pages     = {18 -- 28},
  year      = {2014},
  abstract  = {In this opinion article we propose a scenario detailing how two crucial components have evolved simultaneously to ensure the transition of glycogen to starch in the cytosol of the Archaeplastida last common ancestor: (i) the recruitment of an enzyme from intracellular Chlamydiae pathogens to facilitate crystallization of alpha-glucan chains; and (ii) the evolution of novel types of polysaccharide (de)phosphorylating enzymes from preexisting glycogen (de)phosphorylation host pathways to allow the turnover of such crystals. We speculate that the transition to starch benefitted Archaeplastida in three ways: more carbon could be packed into osmotically inert material; the host could resume control of carbon assimilation from the chlamydial pathogen that triggered plastid endosymbiosis; and cyanobacterial photosynthate export could be integrated in the emerging Archaeplastida.},
  language  = {en}
}