Eric Gomès

Bio: Eric Gomès is an academic researcher from University of Bordeaux. The author has contributed to research in topics: Berry & Anthocyanin. The author has an hindex of 32, co-authored 64 publications receiving 2915 citations. Previous affiliations of Eric Gomès include Centre national de la recherche scientifique & University of Poitiers.

Berry ripening: recently heard through the grapevine

Abstract: Grapevine (Vitis vinifera L.) is a non-climacteric fruit species used as table fruit, dried raisins, and for vinification (wines) and distillation (liquors). In recent years, our knowledge of the molecular basis of ripening regulation has improved. Water status, light conditions, and temperature may hasten, delay, or enhance ripening. Hormones seem to play a central role, as their concentrations change prior to and during ripening and in response to several environmental cues. The review summarizes recent data related to the molecular and hormonal control of grape berry development and ripening, with special emphasis on secondary metabolism and its response to the environment, and pinpoints some experimental limitations.

The ACA4 Gene of Arabidopsis Encodes a Vacuolar Membrane Calcium Pump That Improves Salt Tolerance in Yeast

Abstract: Several lines of evidence suggest that regulation of intracellular Ca2+ levels is crucial for adaptation of plants to environmental stress. We have cloned and characterized Arabidopsis auto-inhibited Ca2+-ATPase, isoform 4 (ACA4), a calmodulin-regulated Ca2+-ATPase. Confocal laser scanning data of a green fluorescent protein-tagged version of ACA4 as well as western-blot analysis of microsomal fractions obtained from two-phase partitioning and Suc density gradient centrifugation suggest that ACA4 is localized to small vacuoles. The N terminus of ACA4 contains an auto-inhibitory domain with a binding site for calmodulin as demonstrated through calmodulin-binding studies and complementation experiments using the calcium transport yeast mutant K616. ACA4 and PMC1, the yeast vacuolar Ca2+-ATPase, conferred protection against osmotic stress such as high NaCl, KCl, and mannitol when expressed in the K616 strain. An N-terminally modified form of ACA4 specifically conferred increased NaCl tolerance, whereas full-length ATPase had less effect.

The ACA4 gene of Arabidopsis encodes a vacuolar membrane calcium pump that improves salt tolerance in yeast. [Erratum: July 2001. v. 126 (3), p. 1341-1342.]

Abstract: Several lines of evidence suggest that regulation of intracellular Ca2+ levels is crucial for adaptation of plants to environmental stress. We have cloned and characterized Arabidopsis auto-inhibited Ca2+ -ATPase, isoform 4 (ACA4), a calmodulin-regulated Ca2+ -ATPase. Confocal laser scanning data of a green fluorescent protein-tagged version of ACA4 as well as western-blot analysis of microsomal fractions obtained from two-phase partitioning and Suc density gradient centrifugation suggest that ACA4 is localized to small vacuoles. The N terminus of ACA4 contains an auto-inhibitory domain with a binding site for calmodulin as demonstrated through calmodulin-binding studies and complementation experiments using the calcium transport yeast mutant K616. ACA4 and PMC1, the yeast vacuolar Ca2+ -ATPase, conferred protection against osmotic stress such as high NaCl, KCl, and mannitol when expressed in the K616 strain. An N-terminally modified form ofACA4 specifically conferred increased NaCl tolerance, whereas full-length ATPase had less effect.

Ecophysiological, Genetic, and Molecular Causes of Variation in Grape Berry Weight and Composition: A Review

Abstract: Berry fresh weight and composition are under the control of complex interactions among genotype, environmental factors, and viticulture practice, which all affect not only the mean value but also the ranges of variation in berry traits. Both mean values and variation range in berry composition play a role in berry quality and, subsequently, wine typicity. This review examines recent ecophysiological, genetic, and molecular knowledge to provide better understanding of the mechanisms that influence variability in berry weight and composition. We specifically reviewed the variation range in berry weight and composition (including sugars, organic acids, and anthocyanins) among Vitis genotypes, the environmental and viticulture practices that cause variability for a given cultivar, the genetic clues underlying the genotypic variation, and the putative genes controlling berry weight and composition. Despite numerous studies comparing differences in the mean value of a berry trait among different environment conditions and viticulture practices, very few studies have explored the level of variation in response to those factors. Present genetic and molecular studies are mainly focused on identifying genes involved in the control of berry weight and composition, with few considerations of environmental factors that affect their expression. In the future, more effort should be directed toward integration of genetic and molecular work with ecophysiological approaches in an effort to gain novel insights into the cause of variability in grape fresh weight and composition.

Chilling tolerance in Arabidopsis involves ALA1, a member of a new family of putative aminophospholipid translocases.

Abstract: The lipid composition of membranes is a key determinant for cold tolerance, and enzymes that modify membrane structure seem to be important for low-temperature acclimation. We have characterized ALA1 (for aminophospholipid ATPase1), a novel P-type ATPase in Arabidopsis that belongs to the gene family ALA1 to ALA11. The deduced amino acid sequence of ALA1 is homologous with those of yeast DRS2 and bovine ATPase II, both of which are putative aminophospholipid translocases. ALA1 complements the deficiency in phosphatidylserine internalization into intact cells that is exhibited by the drs2 yeast mutant, and expression of ALA1 results in increased translocation of aminophospholipids in reconstituted yeast membrane vesicles. These lines of evidence suggest that ALA1 is involved in generating membrane lipid asymmetry and probably encodes an aminophospholipid translocase. ALA1 complements the cold sensitivity of the drs2 yeast mutant. Downregulation of ALA1 in Arabidopsis results in cold-affected plants that are much smaller than those of the wild type. These data suggest a link between regulation of transmembrane bilayer lipid asymmetry and the adaptation of plants to cold.

Climate change 2014 - Mitigation of climate change

Abstract: The talk with present the key results of the IPCC Working Group III 5th assessment report. Concluding four years of intense scientific collaboration by hundreds of authors from around the world, the report responds to the request of the world's governments for a comprehensive, objective and policy neutral assessment of the current scientific knowledge on mitigating climate change. The report has been extensively reviewed by experts and governments to ensure quality and comprehensiveness.

A Renaissance of Elicitors: Perception of Microbe-Associated Molecular Patterns and Danger Signals by Pattern-Recognition Receptors

Abstract: Microbe-associated molecular patterns (MAMPs) are molecular signatures typical of whole classes of microbes, and their recognition plays a key role in innate immunity. Endogenous elicitors are similarly recognized as damage-associated molecular patterns (DAMPs). This review focuses on the diversity of MAMPs/DAMPs and on progress to identify the corresponding pattern recognition receptors (PRRs) in plants. The two best-characterized MAMP/PRR pairs, flagellin/FLS2 and EF-Tu/EFR, are discussed in detail and put into a phylogenetic perspective. Both FLS2 and EFR are leucine-rich repeat receptor kinases (LRR-RKs). Upon treatment with flagellin, FLS2 forms a heteromeric complex with BAK1, an LRR-RK that also acts as coreceptor for the brassinolide receptor BRI1. The importance of MAMP/PRR signaling for plant immunity is highlighted by the finding that plant pathogens use effectors to inhibit PRR complexes or downstream signaling events. Current evidence indicates that MAMPs, DAMPs, and effectors are all perceived as danger signals and induce a stereotypic defense response.

Drought and Salt Tolerance in Plants

Abstract: Agricultural productivity worldwide is subject to increasing environmental constraints, particularly to drought and salinity due to their high magnitude of impact and wide distribution. Traditional breeding programs trying to improve abiotic stress tolerance have had some success, but are limited by the multigenic nature of the trait. Tolerant plants such as Craterostigma plantagenium, Mesembryanthemum crystallinum, Thellungiella halophila and other hardy plants could be valuable tools to dissect the extreme tolerance nature. In the last decade, Arabidopsis thaliana, a genetic model plant, has been extensively used for unravelling the molecular basis of stress tolerance. Arabidopsis also proved to be extremely important for assessing functions for individual stress-associated genes due to the availability of knock-out mutants and its amenability for genetic transformation. In this review, the responses of plants to salt and water stress are described, the regulatory circuits which allow plants to cope wit...

Acyl-Lipid Metabolism

Abstract: Acyl lipids in Arabidopsis and all other plants have a myriad of diverse functions. These include providing the core diffusion barrier of the membranes that separates cells and subcellular organelles. This function alone involves more than 10 membrane lipid classes, including the phospholipids, galactolipids, and sphingolipids, and within each class the variations in acyl chain composition expand the number of structures to several hundred possible molecular species. Acyl lipids in the form of triacylglycerol account for 35% of the weight of Arabidopsis seeds and represent their major form of carbon and energy storage. A layer of cutin and cuticular waxes that restricts the loss of water and provides protection from invasions by pathogens and other stresses covers the entire aerial surface of Arabidopsis. Similar functions are provided by suberin and its associated waxes that are localized in roots, seed coats, and abscission zones and are produced in response to wounding. This chapter focuses on the metabolic pathways that are associated with the biosynthesis and degradation of the acyl lipids mentioned above. These pathways, enzymes, and genes are also presented in detail in an associated website (ARALIP: http://aralip.plantbiology.msu.edu/). Protocols and methods used for analysis of Arabidopsis lipids are provided. Finally, a detailed summary of the composition of Arabidopsis lipids is provided in three figures and 15 tables.