Location: Plant, Soil and Nutrition ResearchTitle: Effects of Al3+ and La3+ trivalent metal ions on tomato fruit proteomes
|SANGIREDDY, SASIKIRAN - Tennessee State University|
|OKEKEOGBU, IKENNA - Tennessee State University|
|YE, ZHUJIA - Tennessee State University|
|ZHOU, SUPING - Tennessee State University|
|Thannhauser, Theodore - Ted|
Submitted to: Proteomes
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/7/2017
Publication Date: 2/11/2017
Citation: Sangireddy, S., Okekeogbu, I., Ye, Z., Zhou, S., Howe, K.J., Fish, T., Thannhauser, T.W. 2017. Effects of Al3+ and La3+ trivalent metal ions on tomato fruit proteomes. Proteomes. 5(1):7. doi:10.3390/proteomoes5010007.
Interpretive Summary: Aluminum (Al3+) toxicity is a major constraint to plant growth and crop yield in acid soils. However, there are other trivalent ions such as lanthium (La3+) having similar valence properties yet exhibit a different phytotoxicity. To examine this phenomenon, tomato plants (Solanum lycopersicum, “Micro-Tom”) were grown hydroponically at pH 4.5 until the first two fruit reached the red ripe stage. At this point the growth media was augmented with either 50 uM Al3+ or 50 uM La3+ for nine days. The protein expression exhibited in the fruit (pericarp) of these plants was then compared between the Al3+ and La3+ treated plants at the mature green (MG), Turning (T) and Red Ripe (RR) stages of development using a multiplexed strategy involving isobaric, isotope coded labeling (iTRAQ). While at the MG stage significantly lower levels of expression was found for proteins involved in protein synthesis, photosynthesis and primary carbon metabolism in the Al3+ treated plants, virtually no difference in expression was found between the treatments at the later stages of development. These results suggest that it is necessary to consider the impacts of certain abiotic stresses on physiological processes such as photosynthesis, primary and secondary metabolites, flavor development etc. as a function of developmental stage and not assume these will be static over time. This study contributes to our understanding of mechanisms involved in adapting to similar, though distinct, toxic metal ions and may lead to novel strategies to enhance tolerance in an import crop plant.
Technical 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 uM 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.