Search

Atmospheric carbon dioxide (CO) directly determines the rate of plant photosynthesis and indirectly effects plant productivity and fitness and may therefore act as a selective pressure driving evolution, but evidence to support this contention is sparse. Using Plantago lanceolata L. seed collected from a naturally high CO spring and adjacent ambient CO control site, we investigated multigenerational response to future, elevated atmospheric CO. Plants were grown in either ambient or elevated CO (700 ?mol mol), enabling for the first time, characterization of the functional and population genomics of plant acclimation and adaptation to elevated CO. This revealed that spring and control plants differed significantly in phenotypic plasticity for traits underpinning fitness including above-ground biomass, leaf size, epidermal cell size and number and stomatal density and index. Gene expression responses to elevated CO (acclimation) were modest [33-131 genes differentially expressed (DE)], whilst those between control and spring plants (adaptation) were considerably larger (689-853 DE genes). In contrast, population genomic analysis showed that genetic differentiation between spring and control plants was close to zero, with no fixed differences, suggesting that plants are adapted to their native CO environment at the level of gene expression. An unusual phenotype of increased stomatal index in spring but not control plants in elevated CO correlated with altered expression of stomatal patterning genes between spring and control plants for three loci (YODA, CDKB1;1 and SCRM2) and between ambient and elevated CO for four loci (ER, YODA, MYB88 and BCA1). We propose that the two positive regulators of stomatal number (SCRM2) and CDKB1;1 when upregulated act as key controllers of stomatal adaptation to elevated CO. Combined with significant transcriptome reprogramming of photosynthetic and dark respiration and enhanced growth in spring plants, we have identified the potential basis of plant adaptation to high CO likely to occur over coming decades.

(1917). XIV. On the partial separation by thermal diffusion of gases of equal molecular weight. The London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science: Vol. 34, No. 200, pp. 146-151.

Summary available.

International audience; Agriculture, and in particular systematic and repeated cultivation of plants, is one of the main characteristics of post-Neolithic sedentary human societies. Deciphering the domestication pathways that have allowed for extensive cultivation of crops is of great scientific importance: first, because it can reveal the patterns and processes of human-induced selection and contribute to the knowledge of the genetic basis of adaptive traits, and second, because identifying the times and locations of domestication is crucial to the understanding of our own evolutionary history, in particular for the last ca. 12,000 years. Finally, the identification of genes involved in domestication could offer potential for future crop improvement. In some instances, knowledge from one crop can be transferred to another to reveal broad patterns, as well as the extent to which parallel evolution has given rise to the crops we rely on today. There have been a number of studies into eggplant domestication, but clarifying the routes and even the number of domestications has until today been limited. This is due to (1) partial knowledge on the identity of eggplant wild relatives, (2) sparse sampling (both in terms of species/accessions and types of data), and (3) inadequacy of the statistical tools used for phylogenetic/demographic inferences. However, the most recent analyses of Solanum melongena point to a single domestication and significant crop-wild-weedy gene flow, which likely hampered earlier phylogenetic attempts. Here, we provide an overview of the current understanding of the domestication frameworks for the three eggplants, Solanum melongena, S. aethiopicum and S. macrocarpon. First, we detail the phenotypical traits of the crops and of their wild progenitors. Then, we detail the historical hypotheses on domestication of eggplants and, when possible, we re-evaluate them in the light of the genomic data generated within the last couple of years.