RESUMO
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.
RESUMO
Progression of leaf senescence depends on several families of transcription factors. In Arabidopsis, the NAC family plays crucial roles in the modulation of leaf senescence; however, the mechanisms involved in this NAC-mediated regulation have not been extensively explored in agronomic species. Petunia hybrida is an ornamental plant that is commonly found worldwide. Decreasing the rate of leaf and petal senescence in P. hybrida is essential for maintaining plant quality. In this study, we examined the NAC-mediated networks involved in regulating senescence in this species. From 41 NAC genes, the expression of which changed in Arabidopsis during leaf senescence, we identified 29 putative orthologs in P. hybrida. Analysis using quantitative real-time-PCR indicated that 24 genes in P. hybrida changed their transcript levels during natural leaf senescence. Leaf-expressed genes were subsequently assessed in petals undergoing natural and pollination-induced senescence. Expression data and phylogenetic analysis were used to generate a list of 10-15 candidate genes; 7 of these were considered key regulatory candidates in senescence because of their consistent upregulation in the three senescence processes examined. Altogether, we identified common and distinct patterns of gene expression at different stages of leaf and petal development and during progression of senescence. The results obtained in this study will contribute to the understanding of NAC-mediated regulatory networks in petunia.
Assuntos
Petunia/genética , Fatores de Transcrição/metabolismo , Flores/genética , Flores/fisiologia , Regulação da Expressão Gênica de Plantas , Petunia/fisiologia , Filogenia , Melhoramento Vegetal , Folhas de Planta/genética , Folhas de Planta/fisiologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Polinização , Fatores de Transcrição/genética , Regulação para CimaRESUMO
Background: Calibrachoa Cerv. (ex La Llave & Lexarza) is a genus of the Solanaceae family (La Llave and Lexarza, 1825). This genus has a high ornamental and economic value due to its intrinsic variability and multiplicity of flower colours. In Argentina there are eight native species, and one of them is Calibrachoa caesia. The genetic diversity among 35 accessions of C. caesia, from five departments in the province of Misiones, was analyzed using ISSR markers. Results: Thirteen ISSR primers yielded a reproducible banding pattern, with 701 amplified loci and 98 percent of polymorphism. The ISSR primers 5CT, 5CA, 5GA, 5GACA, 3CAC, 3TG and 3TC generated 100% polymorphic patterns. The Rp values ranged from 23.20 to 10.29 for 5GACA and 3AG primers, respectively, while the average values for MI and PIC were 0.367 and 0.231, respectively. The more informative primers were 5GACA and 5GA, and the less informative was 3AC. Simple matching coefficient of similarity varied from 0.8875 to 0.6659, indicating high levels of genetic similarity among the genotypes studied. The UPGMA cluster analysis indicated three distinct clusters; one comprised genotypes of the five departments, while the second included individuals from Guaraní and Oberá regions and the third cluster included the San Pedro individuals. The overall grouping pattern is in agreement with principal coordinate analysis (PCoA). Conclusions: The Bayesian cluster analysis revealed structuring of the C. caesia population and two clusters were identified, which correspond to UPGMA major clades. The AMOVA test for all populations showed highest genetic variation within populations (90 percent), meanwhile the Fst coefficient was 0.098, indicating a medium differentiation between populations. These results showed a great intrapopulation genetic diversity but no significant difference was detected among populations...
Assuntos
Marcadores Genéticos , Variação Genética , Repetições de Microssatélites , Petunia/genética , Solanaceae/genéticaRESUMO
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.