Effects of Al3+ and La3+ Trivalent Metal Ions on Tomato Fruit Proteomes

Abstract

The tomato (Solanum lycopersicum) ripening process from mature green (MG) to turning and then to red stages is accompanied by the occurrences of physiological and biochemical reactions, which ultimately result in the formation of the flavor, color and texture of ripe fruits. The two trivalent metal ions Al3+ and La3+ are known to induce different levels of phytotoxicity in suppressing root growth. This paper aims to understand the impacts of these two metal ions on tomato fruit proteomes. Tomato ‘Micro-Tom’ plants were grown in a hydroponic culture system supplemented with 50 μM aluminum sulfate (Al2 (SO4)3.18H2O) for Al3+ or La2(SO4)3 for La3+. Quantitative proteomics analysis, using isobaric tags for relative and absolute quantitation, were performed for fruits at MG, turning and red stages. Results show that in MG tomatoes, proteins involved in protein biosynthesis, photosynthesis and primary carbohydrate metabolisms were at a significantly lower level in Al-treated compared to La-treated plants. For the turning and red tomatoes, only a few proteins of significant differences between the two metal treatments were identified. Results from this study indicate that compared to La3+, Al3+ had a greater influence on the basic biological activities in green tomatoes, but such an impact became indistinguishable as tomatoes matured into the late ripening stages.

Proteomics of Reproductive Development, Fruit Ripening, and Stress Responses in Tomato

“…114 Metal elements such as Al 3+ and La 3+ are able to induce some differential regulation of proteomic fluxes during the green, turning (breaker), and ripe stages of 'MicroTom' tomatoes, with greater influence on the biological activities of green stages. 88 Transcription factors modulate the development stages of fruit ripening by catalyzing the secondary metabolism. A recent study of the role of R2-R3MYB transcription factors in tomatoes reported their involvement in fruit setting from the period of anthesis.…”

“…Some metalloproteases in tomato plants (Sl2-MMP and Sl3-MMP) were characterized to play roles in remodeling the cell wall structure in order to regulate cellular senescence and quick ripening of fruits . Metal elements such as Al 3+ and La 3+ are able to induce some differential regulation of proteomic fluxes during the green, turning (breaker), and ripe stages of ‘MicroTom’ tomatoes, with greater influence on the biological activities of green stages …”