Agrobacterium-mediated genetic transformation of a tropical elite maize line.

ABSTRACT: The efficiency of maize transformation mediated by Agrobacterium tumefaciens is influenced by various factors. The aim of this study was to test the effect of different concentrations of N6 salts (50% ? half strength, and 100% - full strength) in the infection and cocultivation media on genetic transformation efficiency of the L3 tropical elite maize line. Immature embryos were transformed via A. tumefaciens harboring the binary vector pTF102 containing the genes uidA and BAR under control of the CaMV35S promoter. The efficiency of the transgenic events produced was 3% for full strength and 1.1% for half strength N6 salts. Although under a lower concentration of salts, GUS expression was stronger; under this concentration, regeneration was less efficient. Thus, the results showed that the presence of 100% N6 salts in the infection and cocultivation media favored genetic transformation of the L3 maize inbred line mediated by A. tumefaciens

Interaction of genotype, environment and processing in the chemical composition expression and sensorial quality of Arabica coffee.

The present study was carried out to analyze chemical descriptors present in the raw coffee bean and to establish an association of these descriptors with the sensorial quality of the coffee beverage, based on expressions resulting from the interactions of coffee genotype, environment, and processing. The chemical descriptors caffeine, trigonelline, sucrose, and isomers of chlorogenic acid (3-CQA, 4-CQA, and 5-CQA), were analyzed through the use of high performance liquid chromatography (HPLC). Trained and qualified cuppers, certified as judges of specialty coffees, carried out the sensorial analysis using the methodology proposed by the Specialty Coffee Association of America (SCAA). Based on the cultivation environment, altitude and the genotype, it was possible to associate the chemical composition of the raw coffee bean with the coffee beverage sensorial quality. Yellow Bourbon cultivated above 1,200 m of altitude present higher contents of trigonelline and 3-CQA in the raw beans as well as high sensorial quality in the beverage