MicroRNA regulated genes for fleshy fruit quality improvement
Plant microRNAs (miRNAs) constitute a major class of endogenous small RNAs that trigger the sequence-specific post-transcriptional repression of one to several target mRNAs with high sequence complementarity. A decade of miRNA biology studies establish their critical roles in a wide range of developmental processes, stresses and nutrient homeostasis.  During its maturation and ripening the tomato fruit pericarp expresses many miRNAs that target numerous transcription factor mRNAs, hinting on their importance as regulators of these developmental phases. To date, the involvement of only few miRNAs in tomato fruit development through the negative regulation of transcription factors and other proteins has been demonstrated. Still, the functions of many other fruit miRNAs await discovery. To this end our research is focused on the functional characterization of fleshy fruit miRNAs using CRISPR/Cas9 in a hope to understand their functions and utilize them for biotechnological improvements of major agricultural crops.
 
Elucidating the molecular mechanisms underlying fruit set
In angiosperm plants, fruit set is a key developmental milestone that ensures the species' survival, since fruit supports seed development and dispersal. To prevent seedless fruit production, which is futile from the plant's perspective, the ovary, which forms the fruit, ceases to grow shortly before anthesis and enters an ‘ovary arrest’ state. Only if fertilization is successfully completed, a signal believed to be produced by the fertilized ovules provokes the ovary to resume growth, i.e., set fruit. Multiple lines of evidence singled-out the phytohormones auxin and gibberellin (GA) as positive regulators of tomato fruit set, with auxin operating independent and upstream to GA. In tomato, upon fertilization, an increase in auxin and GA levels in the ovary activates corresponding signaling pathways that in turn trigger its growth or fruit set. Still the regulatory mechanism underlying ovary arrest before anthesis and its release following fertilization is not fully understood. We have showed that the ovaries of the tomato AGAMOUS-like-6 (SlAGL6) loss-of-function mutant develop normally until anthesis, but nevertheless can set fruits independent of fertilization (parthenocarpy). This parthenocarpic phenotype is associated with atypical ovule development. Current research is focused on defining SlAGL6 regulated gene network , protein partners and small RNAs that participate in fruit set.