TY  - JOUR
A1  - Meyer, Rhonda C.
A1  - Witucka-Wall, Hanna
A1  - Becher, Martina
A1  - Blacha, Anna Maria
A1  - Boudichevskaia, Anastassia
A1  - Dörmann, Peter
A1  - Fiehn, Oliver
A1  - Friedel, Svetlana
A1  - von Korff, Maria
A1  - Lisec, Jan
A1  - Melzer, Michael
A1  - Repsilber, Dirk
A1  - Schmidt, Renate
A1  - Scholz, Matthias
A1  - Selbig, Joachim
A1  - Willmitzer, Lothar
A1  - Altmann, Thomas
T1  - Heterosis manifestation during early Arabidopsis seedling development is characterized by intermediate gene expression and enhanced metabolic activity in the hybrids
JF  - The plant journal
N2  - 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.
KW  - heterosis
KW  - seedlings
KW  - metabolite profiling
KW  - transcript profiling
KW  - morphological analysis
KW  - Arabidopsis thaliana
KW  - biomass
Y1  - 2012
U6  - https://doi.org/10.1111/j.1365-313X.2012.05021.x
SN  - 0960-7412
VL  - 71
IS  - 4
SP  - 669
EP  - 683
PB  - Wiley-Blackwell
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Brotman, Yariv
A1  - Landau, Udi
A1  - Pnini, Smadar
A1  - Lisec, Jan
A1  - Balazadeh, Salma
A1  - Müller-Röber, Bernd
A1  - Zilberstein, Aviah
A1  - Willmitzer, Lothar
A1  - Chet, Ilan
A1  - Viterbo, Ada
T1  - 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
JF  - Molecular plant
N2  - 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.
KW  - abiotic stress
KW  - chitin-induced signaling
KW  - chitinases
KW  - LysM receptor kinase
KW  - Trichoderma
Y1  - 2012
U6  - https://doi.org/10.1093/mp/sss021
SN  - 1674-2052
VL  - 5
IS  - 5
SP  - 1113
EP  - 1124
PB  - Oxford Univ. Press
CY  - Oxford
ER  -