Induction of isoprenyl diphosphate synthases, plant hormones and defense signalling genes correlates with traumatic resin duct formation in Norway spruce (Picea abies)

Norway spruce (Picea abies) defends itself against herbivores and pathogens by formation of traumatic resin ducts filled with terpenoid-based oleoresin. An important group of enzymes in terpenoid biosynthesis are the short-chain isoprenyl diphosphate synthases which produce geranyl diphosphate (C10), farnesyl diphosphate (C15), and geranylgeranyl diphosphate (C20) as precursors of monoterpenes, sesquiterpenes, and diterpene resin acids, respectively. After treatment with methyl jasmonate (MJ) we investigated the expression of all isoprenyl diphosphate synthase genes characterized to date from Norway spruce and correlated this with formation of traumatic resin ducts and terpene accumulation. Formation of traumatic resin ducts correlated with higher amounts of monoterpenes, sesquiterpenes and diterpene resin acids and an upregulation of isoprenyl diphosphate synthase genes producing geranyl diphosphate or geranylgeranyl diphosphate. Among defense hormones, jasmonate and jasmonate-isoleucine conjugate accumulated to higher levels in trees with extensive traumatic resin duct formation, whereas salicylate did not. Jasmonate and ethylene are likely to both be involved in formation of traumatic resin ducts based on elevated transcripts of genes encoding lipoxygenase and 1-aminocyclopropane-1-carboxylic acid oxidase associated with resin duct formation. Other genes involved in defense signalling in other systems, mitogen-activated protein kinase3 and nonexpressor of pathogenesis-related gene1, were also associated with traumatic resin duct formation. These responses were detected not only at the site of MJ treatment, but also systemically up to 60 cm above the site of treatment on the trunk

The state-of-the-art of grapevine biotechnology and new breeding technologies (NBTS)

Context of the review: The manipulation of the genetic basis controlling grapevine adaptation and phenotypic plasticity can be performed either by classical genetics or biotechnologies. In the last 15 years, considerable knowledge has accumulated about the grapevine genome as well as the mechanisms involved in the interaction of the vine with the environment, pests and diseases. Despite the difficulties associated with genetic mapping in this species (allele diversity, chimerism, long generation intervals...), several major QTLs (quantitative trait loci) controlling important vegetative or reproductive traits have been identified. Considering the huge genotypic and phenotypic diversities existing in Vitis, breeding offers a substantial range of options to improve the performances of cultivars. However, even if marker-assisted selection was largely developed to shorten breeding programs, the selection of improved cultivars, whether for agronomic traits or disease tolerances, is still long and uncertain. Moreover, breeding by crossing does not preserve cultivar genetic background, when the wine industry and market are still based on varietal wines. Significance of the review: In grapevine, pioneering biotechnologies were set up in the 1960s to propagate and/or clean the material from micro-organisms. In the 1990s, the basis of genetic engineering was primary established through biolistic or Agrobacterium with several derived technologies refined in the last 10 years. The latest advance is represented by a group of technologies based on genome editing which allows a much more precise modification of the genome. These technologies, so-called NBTs (new breeding technologies), which theoretically do not deconstruct the phenotype of existing cultivars, could be potentially better accepted by the wine industry and consumers than previous GMO (genetically modified organism) approaches. This paper reviews the current state-ofthe- art of the biotechnologies available for grapevine genome manipulation and future prospects for genetic improvement

Biotech and new breeding technologies: the state-of-the-art and prospects for grapevine improvement

The manipulation of the genetic basis controlling grapevine adaptation and phenotypic plasticity can be performed either by classical genetics or biotechnologies. In the last 15 years, considerable knowledge has accumulated about the grapevine genome as well as the mechanisms involved in the interaction of the vine with the environment, pests and diseases. Despite the difficulties associated with genetic mapping in this species (allele diversity, chimerism, long generation intervals...), several major QTLs controlling important vegetative or reproductive traits, i.e. resistance to diseases have been identified. Considering the huge genotypic and phenotypic diversities existing in Vitis, breeding offers a substantial range of options to improve the performances of cultivars. However, even if marker-assisted selection was largely developed to shorten breeding programs, the selection of improved cultivars, whether for agronomic traits or disease tolerances, is still long and uncertain. Moreover, breeding by crossing breaks the cultivar structure with the wine industry and market still based on varietal wines. In grapevine, pioneering biotechnologies were set up in the 60's to propagate and/or clean the material from microorganisms. In the 90's, the basis of genetic engineering were primary established through biolistic or Agrobacterium with several deriving technologies that were refined in the last 10 years. The lastest advance is represented by a group of technologies based on genome editing which allows a much more precise modification of the genome. These technologies, so-called NBT (new breeding technologies), which doesn't deconstruct the phenotype of the improved cultivar, could be potentially better accepted by the industry and consumers than GMO. This communication will review the current state-of-the- art of the biotechnologies available for grapevine and future prospects for genetic improvement

Grapevine adaptation to abiotic stress: an overview

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Flg22 regulates the release of an ethylene response factor substrate from MAP kinase 6 in Arabidopsis thaliana via ethylene signaling

Mitogen-activated protein kinase (MAPK)–mediated responses are in part regulated by the repertoire of MAPK substrates, which is still poorly elucidated in plants. Here, the in vivo enzyme–substrate interaction of the Arabidopsis thaliana MAP kinase, MPK6, with an ethylene response factor (ERF104) is shown by fluorescence resonance energy transfer. The interaction was rapidly lost in response to flagellin-derived flg22 peptide. This complex disruption requires not only MPK6 activity, which also affects ERF104 stability via phosphorylation, but also ethylene signaling. The latter points to a novel role of ethylene in substrate release, presumably allowing the liberated ERF104 to access target genes. Microarray data show enrichment of GCC motifs in the promoters of ERF104–up-regulated genes, many of which are stress related. ERF104 is a vital regulator of basal immunity, as altered expression in both erf104 and overexpressors led to more growth inhibition by flg22 and enhanced susceptibility to a non-adapted bacterial pathogen

IFN-γ produced by CD8 T cells induces T-bet–dependent and –independent class switching in B cells in responses to alum-precipitated protein vaccine

Alum-precipitated protein (alum protein) vaccines elicit long-lasting neutralizing antibody responses that prevent bacterial exotoxins and viruses from entering cells. Typically, these vaccines induce CD4 T cells to become T helper 2 (Th2) cells that induce Ig class switching to IgG1. We now report that CD8 T cells also respond to alum proteins, proliferating extensively and producing IFN-γ, a key Th1 cytokine. These findings led us to question whether adoptive transfer of antigen-specific CD8 T cells alters the characteristic CD4 Th2 response to alum proteins and the switching pattern in responding B cells. To this end, WT mice given transgenic ovalbumin (OVA)-specific CD4 (OTII) or CD8 (OTI) T cells, or both, were immunized with alum-precipitated OVA. Cotransfer of antigen-specific CD8 T cells skewed switching patterns in responding B cells from IgG1 to IgG2a and IgG2b. Blocking with anti–IFN-γ antibody largely inhibited this altered B-cell switching pattern. The transcription factor T-bet is required in B cells for IFN-γ–dependent switching to IgG2a. By contrast, we show that this transcription factor is dispensable in B cells both for IFN-γ–induced switching to IgG2b and for inhibition of switching to IgG1. Thus, T-bet dependence identifies distinct transcriptional pathways in B cells that regulate IFN-γ–induced switching to different IgG isotypes