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Research, production, and use of genetically modified (GM) crops have split the world between supporters and opponents. Up to now, this technology has been limited to the control of weeds and pests, whereas the second generation of GM crops is expected to assist farmers in abiotic stress tolerance or improved nutritional features. Aiming to analyze this subject holistically, in this presentation we address an advanced technology for drought-tolerant GM crops, upscaling from molecular details obtained in the laboratory to an extensive network of field trials as well as the impact of the introduction of this innovation into the market. Sunflower has divergent transcription factors, which could be key actors in the drought response orchestrating several signal transduction pathways, generating an improved performance to deal with water deficit. One of such factors, HaHB4, belongs to the homeodomain-leucine zipper family and was first introduced in Arabidopsis. Transformed plants had improved tolerance to water deficits, through the inhibition of ethylene sensitivity and not by stomata closure. Wheat and soybean plants expressing the HaHB4 gene were obtained and cropped across a wide range of growing conditions exhibiting enhanced adaptation to drought-prone environments, the most important constraint affecting crop yield worldwide. The performance of wheat and soybean, however, differed slightly across mentioned environments; whereas the improved behavior of GM wheat respect to controls was less dependent on the temperature regime (cool or warm), differences between GM and wild-type soybeans were remarkably larger in warmer compared to cooler conditions. In both species, these GM crops are good candidates to become market products in the near future. In anticipation of consumers' and other stakeholders' interest, spectral analyses of field crops have been conducted to differentiate these GM crops from wild type and commercial cultivars. In this paper, the potential impact of the release of such market products is discussed, considering the perspectives of different stakeholders.
RESUMO
BACKGROUND: Glycosidases profusion in male reproductive fluids suggests a possible relationship with sperm function. Although Hexosaminidase (Hex) is the most active glycosidase in epididymal fluid and seminal plasma, as well as in spermatozoa, Glucosidase is considered a marker for epididymal function and azoospermia. OBJECTIVE: The aim of this study was to determine Hex activity in seminal plasma from patients with normal and abnormal spermograms and analyze its correlation with seminal parameters. MATERIALS AND METHODS: In this cross sectional study, seminal plasma from azoospermic, asthenozoospermic, teratozoospermic, and normozoospermic patients was analyzed for the activity of: total Hex, HexA isoform, and glucosidase. Besides, hexosamine levels were determined, and the amount of Hex was quantified by immunoblot with a specific antibody. Correlation of Hex activity with seminal parameters was also analyzed. RESULTS: Hex activity, like glucosidase, was significantly reduced in azoospermic samples (44, 49, and 60% reduction for total Hex, HexA and glucosidase, respectively). A reduced amount of Hex in azoospermic samples was confirmed by western immunoblot. Hex activity was negatively correlated with round cells in azoospermic samples and positively correlated with motility in asthenozoospermic ones. CONCLUSION: The results suggested that Hex activity was reduced in azoospermic samples and this was due to a lower amount of enzyme. The correlation to seminal parameters related to particular pathologies suggests a possible relationship of Hex with fertilizing capacity.