Characterization and expression analysis of WRKY genes during leaf and corolla senescence of Petunia hybrida plants.

Several families of transcription factors (TFs) control the progression of senescence. Many key TFs belonging to the WRKY family have been described to play crucial roles in the regulation of leaf senescence, mainly in Arabidopsis thaliana. However, little is known about senescence-associated WRKY members in floricultural species. Delay of senescence in leaves and petals of Petunia hybrida, a worldwide ornamental crop are highly appreciated traits. In this work, starting from 28 differentially expressed WRKY genes of A. thaliana during the progression of leaf senescence, we identified the orthologous in P. hybrida and explored the expression profiles of 20 PhWRKY genes during the progression of natural (age-related) leaf and corolla senescence as well as in the corollas of flowers undergoing pollination-induced senescence. Simultaneous visualization showed consistent and similar expression profiles of PhWRKYs during natural leaf and corolla senescence, although weak expression changes were observed during pollination-induced senescence. Comparable expression trends between PhWRKYs and the corresponding genes of A. thaliana were observed during leaf senescence, although more divergence was found in petals of pollinated petunia flowers. Integration of expression data with phylogenetics, conserved motif and cis-regulatory element analyses were used to establish a list of candidates that could regulate more than one senescence process. Our results suggest that several members of the WRKY family of TFs are tightly linked to the regulation of senescence in P. hybrida. Supplementary Information: The online version contains supplementary material available at 10.1007/s12298-022-01243-y.

Construction of a molecular identification profile of new varieties of Nierembergia linariaefolia by anchored microsatellites

The objective of the present work was to establish the molecular identification profile for six new varieties of Nierembergia linariaefolia to incorporate the fingerprint, as complementary information to the standard registration data. Total DNA was extracted from young leaves following the protocol of the cetyltrimethylammonium bromide. Anchored microsatellites were used as molecular markers. The amplification reactions were carried out with seven primers. A total of 251 loci were detected, 98 percent of them were polymorphic. The average of polymorphic loci was 35 loci per primer and, 41 loci per genotype. Six out of the seven primers used discriminated all the individuals involved in the present study; consequently, it was possible to generate the molecular identification profile for the six new varieties. This result, supported together with our previous reports, indicates that the anchored microsatellites are a very useful technique for the fingerprints generation in N. linariaefolia.