Nathalie Hering's Master thesis was awarded with the Prize for the Best Plant Science Master Thesis, which was carried out at KIT Karlsruhe in the year 2019.
In-situ hybridization in Salvia flowers and closely related Lamiaceae for the detection of developmental genes
She detected an unexpected occurrence of B-class identity genes in the ovary of adult Salvia flowers and closely related Lamiaceae
The flower is an evolutionary key innovation that makes a major contribution to the conservation of the species, as a specialized flower-pollinator interaction is the key to preserve the genetic lineage for many species. Within the flower development, there exists so-called "Genes of Speciation", which are significantly involved in producing reproductive barriers. From this, the debate about the species concept could be resolved, as an analysis of these genes could allow a systematically correct classification of the species. In order to understand the flower development in Salvia and closely related Lamiaceae, the temporal and spatial expression pattern of participating homeotic genes must be considered comparatively. Within this work, the expression of the B-class developmental genes GLOBOSA (GLO) and DEFICIENS (DEF) was investigated qualitatively and quantitatively as well as with the help of in-situ hybridization (ISH) in adult Salvia flowers as well as closely related Lamiaceae. ISH is a molecular biology method for the specific detection of nucleic acids in the cell of histological sections in vivo. By applying this method, the developmental genes GLO and DEF could be successfully localized via ISH in the ovary and stamen of flowers of the Lamiaceae.
The occurrence of the B-class identity gene GLO in the stamens corresponds to the ABC model according to Coen and Meyerowitz. The unexpected localization of the two developmental genes GLO and DEF in the ovary might indicate an evolutionary young, unknown protein or point to a repression of the developmental genes by an unknown microRNA in the fourth whorl. The occurrence of the developmental genes in flowers is confirmed by a qualitative and quantitative gene expression analysis. Accurate temporal expression patterns of the developmental genes could not be detected, only that these genes occur more frequently in late developmental stages of flowering. However, the presence of DEF in the leaf implies an early involvement in the combinatorial network of flower development, in addition to its proper function as a B-class identity gene.
Nathalie Hering completed the work at the Botanical Institute I, Department of Biodiversitiy of the Karlsruhe Institute of Technology in the working group of Prof. Dr. Peter Nick.