Human and monogastric animals cannot synthesize 10 out of the 20 amino acids and therefore need to obtain these from their diet. Among the essential amino acids, lysine and threonine are considered to be exceedingly important in that they are the most limiting essential amino acids in cereal grains, which represent the largest source of food worldwide (Bright and Shewry, 1983). Because of the nutritional importance of lysine and threonine, the regulation of their metabolism has been studied extensively at the biochemical, genetic, and, more recently, molecular levels. Like many bacterial species, higher plants synthesize lysine and threonine from aspartate using two different branches of the aspartate family pathway, as shown schematically in Figure 1. The enzymes involved in lysine and threonine synthesis have been reviewed in detail (Bryan, 1980). In this review, I discuss the complex biochemical, cellular, developmental, physiological, and environmental controls of the synthesis of lysine and threonine. I also focus on specific enzymes that play major regulatory roles in the synthesis of these amino acids.

Regulation of Lysine and Threonine Synthesis

Plant microbiome and its manipulation herald a new era for plant biotechnology with the potential to benefit sustainable crop production. However, studies evaluating the diversity, structure and impact of the microbiota in economic important crops are still rare. Here we describe a comprehensive inventory of the structure and assemblage of the bacterial and fungal communities associated with sugarcane. Our analysis identified 23,811 bacterial OTUs and an unexpected 11,727 fungal OTUs inhabiting the endophytic and exophytic compartments of roots, shoots, and leaves. These communities originate primarily from native soil around plants and colonize plant organs in distinct patterns. The sample type is the primary driver of fungal community assemblage, and the organ compartment plays a major role in bacterial community assemblage. We identified core bacterial and fungal communities composed of less than 20% of the total microbial richness but accounting for over 90% of the total microbial relative abundance. The roots showed 89 core bacterial families, 19 of which accounted for 44% of the total relative abundance. Stalks are dominated by groups of yeasts that represent over 12% of total relative abundance. The core microbiome described here comprise groups whose biological role underlies important traits in plant growth and fermentative processes.

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Unlocking the bacterial and fungal communities assemblages of sugarcane microbiome.

The biosynthesis and metabolism of the aspartate derived amino acids in higher plants

Sugarcane bagasse is a large-volume agriculture residue that is generated on a ~540 million metric tons per year basis globally1,2 with the top-three producing countries in Latin America being Brazil (~181 million metric ton yr−1),3 Mexico (15 million metric ton yr−1),4 and Colombia (7 million metric ton yr−1),5 respectively.6 Given sustainability concerns and the need to maximize the utilization of bioresources, the use of sugarcane bagasse is receiving significant attention in biorefining applications, as it is a promising resource for the conversion to biofuels and biopower. This review provides a comprehensive review of bagasse and its chemical constituents and on-going research into its utilization as a feedstock for cellulosic ethanol and electricity generation. © 2016 Society of Chemical Industry and John Wiley & Sons, Ltd

A review of sugarcane bagasse for second‐generation bioethanol and biopower production

Water stress reveals differential antioxidant responses of tolerant and non-tolerant sugarcane genotypes.

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.

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

Lysine-ketoglutarate reductase activity was detected and characterized in the developing endosperm of maize (Zea mays L.). The enzyme showed specificity for its substrates: lysine, α-ketoglutarate, and NADPH. Formation of the reaction product saccharopine was demonstrated. The pH optimum of the enzyme was close to 7, and the Km for lysine and α-ketoglutarate were 5.2 and 1.8 millimolar, respectively.

William Jose da Silva

Papers

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

Lysine-ketoglutarate reductase activity in developing maize endosperm.

Relationship among maize endosperm characteristics of normal and sugary opaque-2 kernels during development