@article{MeyerWituckaWallBecheretal.2012,
  author    = {Meyer, Rhonda C. and Witucka-Wall, Hanna and Becher, Martina and Blacha, Anna Maria and Boudichevskaia, Anastassia and D{\"o}rmann, Peter and Fiehn, Oliver and Friedel, Svetlana and von Korff, Maria and Lisec, Jan and Melzer, Michael and Repsilber, Dirk and Schmidt, Renate and Scholz, Matthias and Selbig, Joachim and Willmitzer, Lothar and Altmann, Thomas},
  title     = {Heterosis manifestation during early Arabidopsis seedling development is characterized by intermediate gene expression and enhanced metabolic activity in the hybrids},
  series = {The plant journal},
  volume    = {71},
  journal   = {The plant journal},
  number    = {4},
  publisher = {Wiley-Blackwell},
  address   = {Hoboken},
  issn      = {0960-7412},
  doi       = {10.1111/j.1365-313X.2012.05021.x},
  pages     = {669 -- 683},
  year      = {2012},
  abstract  = {Heterosis-associated cellular and molecular processes were analyzed in seeds and seedlings of Arabidopsis thaliana accessions Col-0 and C24 and their heterotic hybrids. Microscopic examination revealed no advantages in terms of hybrid mature embryo organ sizes or cell numbers. Increased cotyledon sizes were detectable 4 days after sowing. Growth heterosis results from elevated cell sizes and numbers, and is well established at 10 days after sowing. The relative growth rates of hybrid seedlings were most enhanced between 3 and 4 days after sowing. Global metabolite profiling and targeted fatty acid analysis revealed maternal inheritance patterns for a large proportion of metabolites in the very early stages. During developmental progression, the distribution shifts to dominant, intermediate and heterotic patterns, with most changes occurring between 4 and 6 days after sowing. The highest incidence of heterotic patterns coincides with establishment of size differences at 4 days after sowing. In contrast, overall transcript patterns at 4, 6 and 10 days after sowing are characterized by intermediate to dominant patterns, with parental transcript levels showing the largest differences. Overall, the results suggest that, during early developmental stages, intermediate gene expression and higher metabolic activity in the hybrids compared to the parents lead to better resource efficiency, and therefore enhanced performance in the hybrids.},
  language  = {en}
}
@article{BrotmanLandauPninietal.2012,
  author    = {Brotman, Yariv and Landau, Udi and Pnini, Smadar and Lisec, Jan and Balazadeh, Salma and M{\"u}ller-R{\"o}ber, Bernd and Zilberstein, Aviah and Willmitzer, Lothar and Chet, Ilan and Viterbo, Ada},
  title     = {The LysM Receptor-Like Kinase LysM RLK1 is required to activate defense and abiotic-stress responses induced by overexpression of fungal chitinases in arabidopsis plants},
  series = {Molecular plant},
  volume    = {5},
  journal   = {Molecular plant},
  number    = {5},
  publisher = {Oxford Univ. Press},
  address   = {Oxford},
  issn      = {1674-2052},
  doi       = {10.1093/mp/sss021},
  pages     = {1113 -- 1124},
  year      = {2012},
  abstract  = {Application of crab shell chitin or pentamer chitin oligosaccharide to Arabidopsis seedlings increased tolerance to salinity in wild-type but not in knockout mutants of the LysM Receptor-Like Kinase1 (CERK1/LysM RLK1) gene, known to play a critical role in signaling defense responses induced by exogenous chitin. Arabidopsis plants overexpressing the endochitinase chit36 and hexoaminidase excy1 genes from the fungus Trichoderma asperelleoides T203 showed increased tolerance to salinity, heavy-metal stresses, and Botrytis cinerea infection. Resistant lines, overexpressing fungal chitinases at different levels, were outcrossed to lysm rlk1 mutants. Independent homozygous hybrids lost resistance to biotic and abiotic stresses, despite enhanced chitinase activity. Expression analysis of 270 stress-related genes, including those induced by reactive oxygen species (ROS) and chitin, revealed constant up-regulation (at least twofold) of 10 genes in the chitinase-overexpressing line and an additional 76 salt-induced genes whose expression was not elevated in the lysm rlk1 knockout mutant or the hybrids harboring the mutation. These findings elucidate that chitin-induced signaling mediated by LysM RLK1 receptor is not limited to biotic stress response but also encompasses abiotic-stress signaling and can be conveyed by ectopic expression of chitinases in plants.},
  language  = {en}
}