Nitrogen assimilation in Citrus based on CitEST data mining

Abstract

Assimilation of nitrate and ammonium are vital procedures for plant development and growth. From these primary paths of inorganic nitrogen assimilation, this metabolism integrates diverse paths for biosynthesis of macromolecules, such as amino acids and nucleotides, and the central intermediate metabolism, like carbon metabolism and photorespiration. This paper reports research performed in the CitEST (Citrus Expressed Sequence Tag) database for the main genes involved in nitrogen metabolism and those previously described in other organisms. The results show that a complete cluster of genes involved in the assimilation of nitrogen and the metabolisms of glutamine, glutamate, aspartate and asparagine can be found in the CitEST data. The main enzymes found were nitrate reductase (NR), nitrite reductase (NiR), glutamine synthetase (GS), glutamate synthetase (GOGAT), glutamate dehydrogenase (GDH), aspartate aminotransferase (AspAT) and asparagine synthetase (AS). The different enzymes involved in this metabolism have been shown to be highly conserved among the Citrus and Poncirus species. This work serves as a guide for future functional analysis of these enzymes in citrus.

Biochemical Traits and Physico-Chemical Attributes of Aromatic-Fine Rice in Relation to Yield Potential

“…Whatever the form of nitrogen is applied in the soil, it is synthesized into amino acids and amides for incorporation into the carbon skeletons of different organic molecules. This conversion of nitrogen to amide and amino acids is regulated by the nitrogen assimilating enzymes [7]. For upland crops, nitrate reductase (NR) is the main nitrogen assimilating enzymes which is substrate inducible.…”

Nitrogen Metabolism in Citrus Based on Expressed Tag Analysis

“…According to Kato ( 1986 ) , who performed an excellent revision of nitrogen metabolism and utilization in citrus, NiR had not been reported in citrus yet. However, in CitEST database, NiR was observed predominantly in leaf and fruit tissues (Table 17.3 ) and probably has the same level of expression in both (Wickert et al 2007 ) . It was also observed both in healthy and sick plants manifesting CVC ( X. fastidiosa infection), suggesting that its expression apparently was not (Joy and Hageman 1966 ) .…”

“…Inorganic nitrogen is assimilated and primarily incorporated in organic forms into glutamine, glutamate, asparagines, and aspartate, which in turn constitute the main nitrogen carriers within the plants. These primary amino acids are the major compounds that are used as precursors for the synthesis of other amino acids, amides, and amines, culminating in the production of purine, pyrimidine, and other related reduced nitrogen-carbon compounds (Lam et al 1996 ;Wickert et al 2007 ) .…”

“…Root libraries would have been the primary focus on the nitrogen assimilatory analysis, but they were so scarce that render little contribution (Wickert et al 2007 ) (Wickert et al 2007 ) Bark libraries were poor too, but they have shown entries for more different enzymes. By the time, the leaf and fruit libraries were the most abundant in reads both in healthy and sick conditions (Table 17.3 ).…”

Técnica de mineração de dados: uma revisão da literatura

“…Among these phases, the most important is the data mining, focuses of countless studies in several areas of knowledge (1,7,(9)(10)(13)(14)(15)(16)(17) , that confirms the assumption of the changing of data into information and later into knowledge, which makes the technique necessary for the making-decision process.…”