Proteínas expressas durante a ontogenia do botão floral de algodoeiro (Gossypium hirsutum L.)

Abstract

Cotton is considered one of the main commodities worldwide. In the national scenario, due to its economic and social value, cotton occupies a prominent position as one of the most important crops produced in the country. The genus Gossypium presents unique aspects as to its reproduction and for that reason it attracts the scientific interest. Studies related to the identification of proteins present in the reproductive structure of the cotton plant and their respective genes can help the improvement of plants to obtain cultivars with resistance to insects. In this work, the objective was to investigate the proteins expressed in the floral bud of cotton in different stages of development. In order to establish the best methodology for protein extraction, two protocols were tested: TCA and TCA associated with the phenol method (TCA / Phenol). The second one was the best one, and was chosen for the analysis. The extracted proteins were analyzed by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate (SDS-PAGE). The different phases of development of the floral bud (2 to 20 mm) presented similar protein profile, but with some differentially accumulated bands. A total of 34 bands from 2, 12 and 20 mm floral bud electrophoresis were excised for analysis by mass spectrometry in AutoFlex III ToF / ToF, using MALDI-TOF MS. The mass spectra obtained were analyzed in the MASCOT database, which allowed the identification of 241 proteins accumulated in floral bud of cotton, 132 of these characterized and with clear cellular papers, however only six presented a significant score when compared with the databases, are they: ATP synthase alpha subunit, mitochondrial; Transcription factor RADIALIS; Protein F-box associated with FBD At5g56380; Reticulum-like protein; Acyl carrier protein 2, mitochondrial; and Glyceraldehyde-3-phosphate dehydrogenase. From these results it is possible to infer functional aspects of the floral bud of cotton, as well as its association with physiological and metabolic factors.