**Acknowledgements**

equilibrium for each different isotopic molecule - thermodynamic effect or in the rate with which the isotopes participate in a process or reaction - kinetic effect. Lighter elements, such as H, C, N, O and S suffer more pronounced isotopic variations because of the high relative mass difference between their isotopes. Nevertheless, heavier elements are subject to isotope

A Comprehensive Survey of International Soybean Research - Genetics, Physiology, Agronomy and Nitrogen

As relative abundances cannot be measured directly, these studies are based on measuring the isotope ratio of an element because it is experimental accessible. The isotope ratio meas‐ ured in a particular sample (Rx) is compared to the corresponding one in another sample, frequently a reference sample (RRF) [118]. The differences found are frequently very small and thus high reproducibility/repeatability is required. Thus, the ICP-MS technique is be‐ coming the more advantageous choice for most applications employing isotope ratios, main‐ ly considering the recent instrumental developments. As the elements are subject to isotope fractionation in nature, the genetic modification could also provoke or intensify this effect. In view of that comment here, it is easy to rationalize that many aspects can be explored

The initial hypothesis formulated that the genetic modification itself is stressing the soy‐ bean, is apparently right, once the plant is searching a new equilibrium as living organism. The results presented in this chapter demonstrate that not only is the proteomic map changed with some proteins increasing and others decreasing, but also chromatographic separations are altered when transgenic and non-transgenic soybeans are compared. Exam‐ ples are activities of some enzymes (as CAT, SOD, GPx, among others) involved in neutrali‐ zation of ROS, as well as the possible capacity in taking metals from the soil (mainly for Fe and Cu). Because of these modifications that occur when both transgenic and non-transgenic organisms are compared, the theme of genetic modification could be even better explained with some alternative strategies, such as quantitative proteomics, image analysis, tracer ex‐

Finally, in our point of view, one of the key points for the success of studies involving trans‐ genic organisms is not only to involve good technology, but also a transdisciplinary view, involving different areas of expertise. With this strategy, it will be easier to understand this area of investigation, making possible the demystification of the genetic modification that

have occurred, and allowing answers for some questions that still remain unknown.

2-D-HPLC Two-Dimensional High Performance Liquid Chromatography

fractionation, even though the change is minor [121].

when focusing on studies related to transgenic soybean.

periments with stable isotopes, and other possibilities.

**10. Nomenclature and acronyms**

2-D PAGE Two-Dimensional Gel Electrophoresis

**9. Conclusion**

Relationships

602

The authors are grateful to the Fundação de Amparo a Pesquisa do Estado de São Paulo (FAPESP, São Paulo, Brazil), Conselho Nacional de Desenvolvimento Científico e Tecnológi‐ co (CNPq, Brasília, Brazil), and Coordenação de Aperfeiçoamento de Pessoal de Nível Supe‐ rior (CAPES, Brasília, Brazil), for financial support.
