The Impact of Callose Metabolism on the Mechanical Properties of Cell Wall during Tomato Ripening .

Projektbeschreibung

Die Rolle der Callose beim Reifeprozess von Tomaten

Aufgrund ihrer ernährungsphysiologischen Eigenschaften gilt die Tomate als eine der wichtigsten Nutzpflanzen überhaupt. Doch als weiche Frucht verliert sie schnell viel von ihrer festen Konsistenz. Durch widerstandsfähigere Sorten ließen sich Erzeugung, Verarbeitung und Transport deutlich optimieren. Forschungsergebnisse deuten darauf hin, dass das β-1,3-Glucan Callose am Abbau der Fruchtfestigkeit beteiligt ist. Im EU-finanzierten Projekt CallMechanics soll die Rolle der Callose beim Weichwerden der Frucht untersucht werden, um herauszufinden, wie sich Veränderungen in der Callose-Akkumulation auf die späten Phasen der Fruchterzeugung auswirken. Daraus ergeben sich neue molekulare Instrumente, die bei Auswahl und Anbau widerstandsfähigerer Sorten zum Einsatz kommen.

Ziel

Tomato, SolanTomato, Solanum lycopersicum L. is one of the most important crops and an important source of nutrients in the world. However, around 25-42% of the yield are lost during postharvest. Rapid softening is one of the main causes reducing the shelf-life of the fruit. Therefore, delaying this process is one of the major targets in fruit breeding programmes.
Evidence show that stimulating callose in tomatoes via bruising or heating induce changes in fruit texture. In this project, the impact on fruit softening of cell wall modifications targeting the synthesis/degradation of the beta 1,3 glucan component (named callose) will be investigated. The aim is to determine how changes in callose accumulation at the latest stages of fruit development modify the texture, the structural and mechanical properties of tomato fruit. Introgression and transgenic lines with modified callose metabolism will be generated and cell wall biochemistry and mechanical properties will be characterized combining cross-disciplinary approaches such as immunolocalization, Fourier-transformed infrared, nano and macro indentation and Raman spectroscopy. Moreover, the impact of callose modifications on plant/fruit development and on other processes related to softening (such as water content or pathogen susceptibility) will be determined.
The results of our project will provide novel molecular tools to use in the selection and breeding of fruit varieties. As a direct outcome, we expect to obtain plants producing fruits that maintain their firmness for a longer period of time, thus with reduce susceptibility to mechanical damage and pathogen attack during the postharvest period. This achievement will have a positive impact on the European Union economy by optimizing processes such as the frequency of harvesting, the handling and the transport procedures. It will also impact on human health and food security by reducing losses and the spreading of pathogens that thrive in mature soft fruits.