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| Author(s): |
Susan Ienne da Silva Vançan
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Instituto de Ciências Biomédicas (ICB/SDI) |
| Defense date: | 2012-05-22 |
| Examining board members: |
Bianca Silvana Zingales;
Marcelo Ribeiro da Silva Briones;
Ariel Mariano Silber;
Marta Maria Geraldes Teixeira;
Lucile Maria Floeter Winter
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| Advisor: | Bianca Silvana Zingales |
| Abstract | |
A gene codifying a pyruvate/indolepyruvate decarboxylase (PDC/IPDC) is present in the plant trypanosomatid Phytomonas serpens. PDC acts in the alcoholic fermentation, whyle IPDC acts in the biosynthesis of the phytohormone indole-3-acetic acid (IAA). Phylogenetic analysis indicate that P. serpens PDC/IPDC is monophyletic with gamma-proteobacteria IPDCs, suggesting a horizontal gene transfer event. Analysis of P. serpens culture media confirms production of ethanol and IAA. The functionality of the phytohormone was confirmed by tomato hypocotyl elongation tests. Tomatoes inoculated with P. serpens showed an increase in the concentration of IAA amide and ester conjugated. PDC activity was shown in P. serpens extracts. We conclude that the PDC/IPDC would be a 2-keto acid decaboxylase with variable catalytic activity for different substrates. The PDC activity appears to be prevalent in P. serpens representing a mechanism to oxidize part of NADH formed in glycolysis, responsible for ATP production in this organism. (AU) | |