title: Heterosis manifestation during early Arabidopsis seedling development is characterized by intermediate gene expression and enhanced metabolic activity in the hybrids.
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.
authors.affiliation: Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Corrensstraße 3, 06466 Gatersleben, Germany. meyer@ipk-gatersleben.de
authors.forename: Rhonda C
authors.initials: RC
authors.lastname: Meyer
authors.forename: Hanna
authors.initials: H
authors.lastname: Witucka-Wall
authors.forename: Martina
authors.initials: M
authors.lastname: Becher
authors.forename: Anna
authors.initials: A
authors.lastname: Blacha
authors.forename: Anastassia
authors.initials: A
authors.lastname: Boudichevskaia
authors.forename: Peter
authors.initials: P
authors.lastname: Dörmann
authors.forename: Oliver
authors.initials: O
authors.lastname: Fiehn
authors.forename: Svetlana
authors.initials: S
authors.lastname: Friedel
authors.forename: Maria
authors.initials: M
authors.lastname: von Korff
authors.forename: Jan
authors.initials: J
authors.lastname: Lisec
authors.forename: Michael
authors.initials: M
authors.lastname: Melzer
authors.forename: Dirk
authors.initials: D
authors.lastname: Repsilber
authors.forename: Renate
authors.initials: R
authors.lastname: Schmidt
authors.forename: Matthias
authors.initials: M
authors.lastname: Scholz
authors.forename: Joachim
authors.initials: J
authors.lastname: Selbig
authors.forename: Lothar
authors.initials: L
authors.lastname: Willmitzer
authors.forename: Thomas
authors.initials: T
authors.lastname: Altmann
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development* / Q000378:metabolism*; D005227:Fatty Acids / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D018525:Germination; D006823:Hybrid Vigor; D036226:Seedlings / Q000235:genetics / Q000254:growth & development / Q000378:metabolism
chemical_list: D005227:Fatty Acids