Project description:In plants, microRNAs (miRNAs) play a critical role in post-transcriptional gene regulation and have been shown to control many genes involved in various biological and metabolic processes. Deep sequencing technologies have facilitated identification of species-specific or lowly expressed as well as conserved or highly expressed miRNAs in plants. Strawberry is one of the most economically important fruit throughout the world.Although miRNAs have been extensively studied in the past five years, limited systematic study of miRNAs has been performed on the Fragaria genus. These results show that regulatory miRNAs exist in agronomically important strawberry and may play an important role in strawberry growth, development, and response to disease.
Project description:Breeding day-neutral strawberry (Fragaria x ananassa Duchesne) is pivotal to extend fruit-bearing season and increase the efficiency of production. However, genetic improvement of day-neutrality by the means of molecular marker technologies remains slow due to genome complexity of octoploid strawberry. This study employs an innovative approach by integrating the Subtracted Diversity Array (SDA) technology and Bulked Segregant Analysis (BSA) to facilitate the identification of molecular markers associated with day-neutrality in octoploid strawberry. A Fragaria Discovery Panel (FDP) containing 287 features specific to strawberry genome was constructed as a platform for rapid screening of DNA polymorphism between one short day (SD) strawberry DNA bulk and three day-neutral (DN) bulks varrying in flowering strength. Differential array hybridisation patterns between the DN and SD bulks revealed a novel molecular marker, FaP2E11, closely linked to CYTOKININ OXIDASE 1 (CKX1) gene possibly involved in promoting flowering under non-inductive condition. Interestingly, a 12 bp deletion was observed within the FaP2E11 sequence cloned from SD genotypes but not DN genotypes. As cytokinin is required to induce flowering, this result indicates that full sequence of FaP2E11 and the sequence with deletion are allelic variants linked to the low enzyme activity CKX1 and the wild type alleles, respectively.
Project description:Strawberry cultivation is associated with high mineral fertilizer doses and excessive use of chemical plant protection products. Based on previous research, we expected that chitin application to the growing medium will increase the nutrient availability and activate the plant’s systemic defense response, resulting in higher strawberry yields and less disease symptoms. We set up two experiments in which the temporal variability and differences in initial nutrient concentrations of the growing media were taken into account. Chitin induced the plant’s shoot biomass, explained by elevated N concentration in the growing medium and/or the attraction of plant-growth promoting fungal genera towards the plant root, such as Mortierella and Umbelopsis. The over-excessive N concentration and P and K deficiencies in the chitin treatment led to nutrient disbalances. This may explain the decreased fruit yield and disease resistance of the fruits towards Botrytis cinerea. In contrast, chitin caused a clear defense priming effect of the strawberry leaves, with a strong induction of the jasmonic acid response, resulting in less disease symptoms. Chitin caused positive effects on shoot growth and disease resistance of the leaves, but caution needs to be taken for nutrient disbalances leading to negative influences on fruit production and disease susceptibly.
Project description:In plants, microRNAs (miRNAs) play a critical role in post-transcriptional gene regulation and have been shown to control many genes involved in various biological and metabolic processes. Deep sequencing technologies have facilitated identification of species-specific or lowly expressed as well as conserved or highly expressed miRNAs in plants. Strawberry is one of the most economically important fruit throughout the world.Although miRNAs have been extensively studied in the past five years, limited systematic study of miRNAs has been performed on the Fragaria genus. These results show that regulatory miRNAs exist in agronomically important strawberry and may play an important role in strawberry growth, development, and response to disease. High throughput sequencing was employed to identify miRNAs in strawberry and try to describe their functions in strawberry growth and development