Among the different biosynthetic pathways found in extant organisms, lysine biosynthesis is peculiar because it has two different anabolic routes. One is the diaminopimelic acid pathway (DAP), and the other over the a-aminoadipic acid route (AAA). A variant of the AAA route that includes some enzymes involved in arginine and leucine biosyntheses has been recently reported in Thermus thermophilus (Nishida et al. 1999). Here we describe the results of a detailed genomic analysis of each of the sequences involved in the two lysine anabolic routes, as well as of genes from other routes related to them. No evidence was found of an evolutionary relationship between the DAP and AAA enzymes. Our results suggest that the DAP pathway is related to arginine metabolism, since the lysC, asd, dapC, dapE, and lysA genes from lysine biosynthesis are related to the argB, argC, argD, argE, and speAC genes, respectively, whose products catalyze different steps in arginine metabolism. This work supports previous reports on the relationship between AAA gene products and some enzymes involved in leucine biosynthesis and the tricarboxylic acid cycle (Irvin and Bhattacharjee 1998; Miyazaki et al. 2001). Here we discuss the significance of the recent finding that several genes involved in the arginine (Arg) and leucine (Leu) biosynthesis participate in a new alternative route of the AAA pathway (Miyazaki et al. 2001). Our results demonstrate a clear relationship between the DAP and Arg routes, and between the AAA and Leu pathways.

This study provides a better understanding of the perspective and attitudes of farmers towards sustainable land management (SLM) practices in central Spain. Farmer's willingness to change from conventional tillage to cover crops in vineyards is seen as an indicator for adoption of sustainable agriculture. Two complementary approaches were used: open interviews (n = 25) and surveys (n = 64). The portrait of these winegrowers is of mature farmers, owners of their lands and conscious of soil erosion problems (81%), although not on their own lands. They observe soil degradation (45%); however, they are more conscious of problems in their vines or grapes (64%). Only 32% would be willing to use cover crops to avoid erosion. The barriers for adoption were mainly related to water constraints, lack of knowledge and inability to accept production decreases. Results indicate an underlying lack of information on SLM. They show confusion or mistakes regarding the relationship between tillage and erosion. Young farmers are more prone to change practices. Scientific results are not effectively communicated; there are no efficient local structures to provide them with knowledge and advice in their work, including guidance on environmental issues. The EU agri‐environment payments cover the costs of SLM practices for avoiding erosion or compaction and increasing SOC. In spite of that, participants do not apply for subsidies to compensate the income foregone. Policy makers, extension services and scientists have to face this situation to tackle the limited knowledge transfer revealed in this study. Copyright © 2014 John Wiley & Sons, Ltd.

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The possibility of a high-temperature origin of life has gained support based on indirect evidence of a hot, early Earth and on the basal position of hyperthermophilic organisms in rRNA-based phylogenies. However, although the availability of more than 80 completely sequenced cellular genomes has led to the identification of hyperthermophilic-specific traits, such as a trend towards smaller genomes, reduced protein-encoding gene sizes, and glutamic-acid-rich simple sequences, none of these characteristics are in themselves an indication of primitiveness. There is no geological evidence for the physical setting in which life arose, but current models suggest that the Earth's surface cooled down rapidly. Moreover, at 100 degrees C the half-lives of several organic compounds, including ribose, nucleobases, and amino acids, which are generally thought to have been essential for the emergence of the first living systems, are too short to allow for their accumulation in the prebiotic environment. Accordingly, if hyperthermophily is not truly primordial, then heat-loving lifestyles may be relics of a secondary adaptation that evolved after the origin of life, and before or soon after separation of the major lineages.

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