Sugarcane (Saccharum X officinarum): A Reference Study for the Regulation of Genetically Modified Cultivars in Brazil

Global interest in sugarcane has increased significantly in recent years due to its economic impact on sustainable energy production. Sugarcane breeding and better agronomic practices have contributed to a huge increase in sugarcane yield in the last 30 years. Additional increases in sugarcane yield are expected to result from the use of biotechnology tools in the near future. Genetically modified (GM) sugarcane that incorporates genes to increase resistance to biotic and abiotic stresses could play a major role in achieving this goal. However, to bring GM sugarcane to the market, it is necessary to follow a regulatory process that will evaluate the environmental and health impacts of this crop. The regulatory review process is usually accomplished through a comparison of the biology and composition of the GM cultivar and a non-GM counterpart. This review intends to provide information on non-GM sugarcane biology, genetics, breeding, agronomic management, processing, products and byproducts, as well as the current technologies used to develop GM sugarcane, with the aim of assisting regulators in the decision-making process regarding the commercial release of GM sugarcane cultivars

Nitrite as the major source of nitric oxide production by Arabidopsis thaliana in response to Pseudomonas syringae

The origin of nitric oxide (,NO) in plants is unclear and an 'NO synthase (NOS)-like enzyme and nitrate reductase (NR) are claimed as potential sources. Here we used wild-type and NR-defective double mutant plants to investigate 'NO production in Arabidopsis thaliana in response to Pseudomonas syringae pv maculicola. NOS activity increased substantially in leaves inoculated with P. syringae. However, electron paramagnetic resonance experiments showed a much higher 'NO formation that was dependent on nitrite and mitochondrial electron transport rather than on arginine or nitrate. Overall, these results indicate that NOS, NR and a mitochondrial-dependent nitrite-reducing activity cooperate to produce 'NO during A. thaliana-P. syringae interaction. (c) 2005 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.579173814382

Decreased arginine and nitrite levels in nitrate reductase-deficient Arabidopsis thaliana plants impair nitric oxide synthesis and the hypersensitive response to Pseudomonas syringae

Nitric oxide ((center dot)NO) produced in plants is implicated in defense responses against pathogens. (center dot)NO synthesis in such conditions has been attributed to a nitric oxide synthase (NOS)-like enzyme and, more recently, to a mitochondrial-dependent NO(2)(-)-reducing activity. In this work, we used an NR-deficient double mutant (nia1 nia2) of Arabidopsis thaliana that is deficient in endogenous NO(2)(-) to analyse the hypersensitive response (HR) against an avirulent strain of Pseudomonas syringae pv. maculicola (Psm). The inoculation of Psm into nia1 nia2 A. thaliana caused leaf chlorosis whereas the HR was induced in wild-type plants. (center dot)NO production in situ was substantially increased in wild-type but not in nia1 nia2 leaves following inoculation of Psm, as measured with the fluorescent (center dot)NO indicator 4,5-diaminofluorescein diacetate. However, the infiltration of L-arginine or NO(2)(-) into nia1 nia2 leaves triggered (center dot)NO production in situ. Moreover, co-infiltration of NO(2)(-) and Psm restored the HR in the leaves of nia1 nia2 plants. The total content of free amino acids, particularly L-arginine, was much lower in nia1 nia2 leaves compared to wild-type leaves. Overall, these results suggest that the HR is affected in NR-deficient plants because these plants lack L-arginine and NO(2)(-), two important endogenous substrates for (center dot)NO synthesis. (c) 2006 Elsevier Ireland Ltd. All rights reserved.1711344