@article{ApeltBreuerNikoloskietal.2015,
  author    = {Apelt, Federico and Breuer, David and Nikoloski, Zoran and Stitt, Mark and Kragler, Friedrich},
  title     = {Phytotyping(4D): a light-field imaging system for non-invasive and accurate monitoring of spatio-temporal plant growth},
  series = {The plant journal},
  volume    = {82},
  journal   = {The plant journal},
  number    = {4},
  publisher = {Wiley-Blackwell},
  address   = {Hoboken},
  issn      = {0960-7412},
  doi       = {10.1111/tpj.12833},
  pages     = {693 -- 706},
  year      = {2015},
  abstract  = {Integrative studies of plant growth require spatially and temporally resolved information from high-throughput imaging systems. However, analysis and interpretation of conventional two-dimensional images is complicated by the three-dimensional nature of shoot architecture and by changes in leaf position over time, termed hyponasty. To solve this problem, Phytotyping(4D) uses a light-field camera that simultaneously provides a focus image and a depth image, which contains distance information about the object surface. Our automated pipeline segments the focus images, integrates depth information to reconstruct the three-dimensional architecture, and analyses time series to provide information about the relative expansion rate, the timing of leaf appearance, hyponastic movement, and shape for individual leaves and the whole rosette. Phytotyping(4D) was calibrated and validated using discs of known sizes, and plants tilted at various orientations. Information from this analysis was integrated into the pipeline to allow error assessment during routine operation. To illustrate the utility of Phytotyping(4D), we compare diurnal changes in Arabidopsis thaliana wild-type Col-0 and the starchless pgm mutant. Compared to Col-0, pgm showed very low relative expansion rate in the second half of the night, a transiently increased relative expansion rate at the onset of light period, and smaller hyponastic movement including delayed movement after dusk, both at the level of the rosette and individual leaves. Our study introduces light-field camera systems as a tool to accurately measure morphological and growth-related features in plants. Significance Statement Phytotyping(4D) is a non-invasive and accurate imaging system that combines a 3D light-field camera with an automated pipeline, which provides validated measurements of growth, movement, and other morphological features at the rosette and single-leaf level. In a case study in which we investigated the link between starch and growth, we demonstrated that Phytotyping(4D) is a key step towards bridging the gap between phenotypic observations and the rich genetic and metabolic knowledge.},
  language  = {en}
}
@article{HansenMeyerFerrarietal.2017,
  author    = {Hansen, Bjoern Oest and Meyer, Etienne H. and Ferrari, Camilla and Vaid, Neha and Movahedi, Sara and Vandepoele, Klaas and Nikoloski, Zoran and Mutwil, Marek},
  title     = {Ensemble gene function prediction database reveals genes important for complex I formation in Arabidopsis thaliana},
  series = {New phytologist : international journal of plant science},
  volume    = {217},
  journal   = {New phytologist : international journal of plant science},
  number    = {4},
  publisher = {Wiley},
  address   = {Hoboken},
  issn      = {0028-646X},
  doi       = {10.1111/nph.14921},
  pages     = {1521 -- 1534},
  year      = {2017},
  abstract  = {Recent advances in gene function prediction rely on ensemble approaches that integrate results from multiple inference methods to produce superior predictions. Yet, these developments remain largely unexplored in plants. We have explored and compared two methods to integrate 10 gene co-function networks for Arabidopsis thaliana and demonstrate how the integration of these networks produces more accurate gene function predictions for a larger fraction of genes with unknown function. These predictions were used to identify genes involved in mitochondrial complex I formation, and for five of them, we confirmed the predictions experimentally. The ensemble predictions are provided as a user-friendly online database, EnsembleNet. The methods presented here demonstrate that ensemble gene function prediction is a powerful method to boost prediction performance, whereas the EnsembleNet database provides a cutting-edge community tool to guide experimentalists.},
  language  = {en}
}
@article{KuekenGennermannNikoloski2020,
  author    = {K{\"u}ken, Anika and Gennermann, Kristin and Nikoloski, Zoran},
  title     = {Characterization of maximal enzyme catalytic rates in central metabolism of Arabidopsis thaliana},
  series = {The plant journal},
  volume    = {103},
  journal   = {The plant journal},
  number    = {6},
  publisher = {Wiley},
  address   = {Oxford},
  issn      = {0960-7412},
  doi       = {10.1111/tpj.14890},
  pages     = {2168 -- 2177},
  year      = {2020},
  abstract  = {Availability of plant-specific enzyme kinetic data is scarce, limiting the predictive power of metabolic models and precluding identification of genetic factors of enzyme properties. Enzyme kinetic data are measuredin vitro, often under non-physiological conditions, and conclusions elicited from modeling warrant caution. Here we estimate maximalin vivocatalytic rates for 168 plant enzymes, including photosystems I and II, cytochrome-b6f complex, ATP-citrate synthase, sucrose-phosphate synthase as well as enzymes from amino acid synthesis with previously undocumented enzyme kinetic data in BRENDA. The estimations are obtained by integrating condition-specific quantitative proteomics data, maximal rates of selected enzymes, growth measurements fromArabidopsis thalianarosette with and fluxes through canonical pathways in a constraint-based model of leaf metabolism. In comparison to findings inEscherichia coli, we demonstrate weaker concordance between the plant-specificin vitroandin vivoenzyme catalytic rates due to a low degree of enzyme saturation. This is supported by the finding that concentrations of nicotinamide adenine dinucleotide (phosphate), adenosine triphosphate and uridine triphosphate, calculated based on our maximalin vivocatalytic rates, and available quantitative metabolomics data are below reportedKMvalues and, therefore, indicate undersaturation of respective enzymes. Our findings show that genome-wide profiling of enzyme kinetic properties is feasible in plants, paving the way for understanding resource allocation.},
  language  = {en}
}
@article{PandeyYuOmranianetal.2019,
  author    = {Pandey, Prashant K. and Yu, Jing and Omranian, Nooshin and Alseekh, Saleh and Vaid, Neha and Fernie, Alisdair R. and Nikoloski, Zoran and Laitinen, Roosa A. E.},
  title     = {Plasticity in metabolism underpins local responses to nitrogen in Arabidopsis thaliana populations},
  series = {Plant Direct},
  volume    = {3},
  journal   = {Plant Direct},
  number    = {11},
  publisher = {John Wiley \& sonst LTD},
  address   = {Chichester},
  issn      = {2475-4455},
  doi       = {10.1002/pld3.186},
  pages     = {6},
  year      = {2019},
  abstract  = {Nitrogen (N) is central for plant growth, and metabolic plasticity can provide a strategy to respond to changing N availability. We showed that two local A. thaliana populations exhibited differential plasticity in the compounds of photorespiratory and starch degradation pathways in response to three N conditions. Association of metabolite levels with growth-related and fitness traits indicated that controlled plasticity in these pathways could contribute to local adaptation and play a role in plant evolution.},
  language  = {en}
}