Search results for "REGULATION"

Sex versus parthenogenesis: A transcriptomic approach of photoperiod response in the model aphid Acyrthosiphon pisum (Hemiptera: Aphididae)

2007

International audience; Most aphids develop a cyclic parthenogenesis life-cycle. After several generations of viviparous parthenogenetic females, it follows a single annual generation of sexual individuals, usually in autumn, that mate and lay the sexual eggs. Shortening of photoperiod at the end of the summer is a key factor inducing the sexual response. With the survey here reported we aimed at identifying a collection of candidate genes to participate at some point in the cascade of events that lead to the sexual phenotypes. Following a suppression subtractive hybridization methodology (SSH) on the model aphid Acyrthosiphon pisum, we built and characterised two reciprocal cDNA libraries …

Stimulation of Defense Reactions in Medicago truncatula by Antagonistic Lipopeptides from Paenibacillus sp. Strain B2

2010

ABSTRACT With the aim of obtaining new strategies to control plant diseases, we investigated the ability of antagonistic lipopolypeptides (paenimyxin) from Paenibacillus sp. strain B2 to elicit hydrogen peroxide (H 2 O 2 ) production and several defense-related genes in the model legume Medicago truncatula . For this purpose, M. truncatula cell suspensions were used and a pathosystem between M. truncatula and Fusarium acuminatum was established. In M. truncatula cell cultures, the induction of H 2 O 2 reached a maximum 20 min after elicitation with paenimyxin, whereas concentrations higher than 20 μM inhibited H 2 O 2 induction and this was correlated with a lethal effect. In plant roots in…

Changes in carbohydrate metabolism in Plasmopara viticola-infected grapevine leaves.

2011

International audience; The oomycete Plasmopara viticola is responsible for downy mildew, a severe grapevine disease. In infected grapevine leaves, we have observed an abnormal starch accumulation at the end of the dark period, suggesting modifications in starch metabolism. Therefore, several complementary approaches, including transcriptomic analyses, measurements of enzyme activities, and sugar quantification, were performed in order to investigate and to understand the effects of P. viticola infection on leaf starch and-to a larger extent-carbohydrate metabolism. Our results indicate that starch accumulation is associated with an increase in ADP-glucose pyrophosphorylase (AGPase) activit…

2019

PIWI proteins and their guiding Piwi-interacting (pi-) RNAs direct the silencing of target nucleic acids in the animal germline and soma. Although in mammal testes fetal piRNAs are involved in extensive silencing of transposons, pachytene piRNAs have additionally been shown to act in post-transcriptional gene regulation. The bulk of pachytene piRNAs is produced from large genomic loci, named piRNA clusters. Recently, the presence of reversed pseudogenes within piRNA clusters prompted the idea that piRNAs derived from such sequences might direct regulation of their parent genes. Here, we examine primate piRNA clusters and integrated pseudogenes in a comparative approach to gain a deeper unde…

Assessment of genetically modified soybean MON 87751 for food and feed uses under Regulation (EC) No 1829/2003 (application EFSA‐GMO‐NL‐2014‐121)

2018

Abstract Soybean MON 87751 was developed through Agrobacterium tumefaciens‐mediated transformation to provide protection certain specific lepidopteran pests by the expression of the Cry1A.105 and Cry2Ab2 proteins derived from Bacillus thuringiensis. The molecular characterisation data and bioinformatic analyses did not identify issues requiring assessment for food and feed safety. None of the compositional, agronomic and phenotypic differences identified between soybean MON 87751 and the conventional counterpart required further assessment. The GMO Panel did not identify safety concerns regarding the toxicity and allergenicity of the Cry1A.105 and Cry2Ab2 proteins as expressed in soybean MO…

Scientific Opinion on application EFSA‐GMO‐BE‐2013‐117 for authorisation of genetically modified maize MON 87427 × MON 89034 × NK603 and subcombinati…

2017

Scientific opinionRequestor: Competent Authority of BelgiumQuestion number: EFSA-Q-2013-00765; In this opinion, the EFSA Panel on Genetically Modified Organisms (GMO Panel) assessed the three-event stack maize MON 87427 9 MON 89034 9 NK603 and its three subcombinations, independently of their origin. The GMO Panel has previously assessed the three single events combined to produce this three-event stack maize and did not identify safety concerns. No new data on the single events, leading to modification of the original conclusions on their safety, were identified. Based on the molecular, agronomic, phenotypic and compositional characteristics, the combination of the single maize events and …

AtCCS is a functional homolog of the yeast copper chaperone Ccs1/Lys7

2005

AbstractIn plant chloroplasts two superoxide dismutase (SOD) activities occur, FeSOD and Cu/ZnSOD, with reciprocal regulation in response to copper availability. This system presents a unique model to study the regulation of metal-cofactor delivery to an organelle. The Arabidopsis thaliana gene AtCCS encodes a functional homolog to yeast Ccs1p/Lys7p, a copper chaperone for SOD. The AtCCS protein was localized to chloroplasts where it may supply copper to the stromal Cu/ZnSOD. AtCCS mRNA expression levels are upregulated in response to Cu-feeding and senescence. We propose that AtCCS expression is regulated to allow the most optimal use of Cu for photosynthesis.

Expression of xyloglucan endotransglucosylase/hydrolase (XTH) genes and XET activity in ethylene treated apple and tomato fruits.

2013

[EN] Xyloglucan endotransglucosylase/hydrolase (XTHs: EC 2.4.1.207 and/or EC 3.2.1.151), a xyloglucan modifying enzyme, has been proposed to have a role during tomato and apple fruit ripening by loosening the cell wall. Since the ripening of climacteric fruits is controlled by endogenous ethylene biosynthesis, we wanted to study whether XET activity was ethylene-regulated, and if so, which specific genes encoding ripening-regulated XTH genes were indeed ethylene-regulated. XET specific activity in tomato and apple fruits was significantly increased by the ethylene treatment, as compared with the control fruits, suggesting an increase in the XTH gene expression induced by ethylene. The 25 Sl…

Experimental increase in fecundity causes upregulation of fecundity and body maintenance genes in the fat body of ant queens.

2021

In most organisms, fecundity and longevity are negatively associated and the molecular regulation of these two life-history traits is highly interconnected. In addition, nutrient intake often has opposing effects on lifespan and reproduction. In contrast to solitary insects, the main reproductive individual of social hymenopterans, the queen, is also the most long-lived. During development, queen larvae are well-nourished, but we are only beginning to understand the impact of nutrition on the queens' adult life and the molecular regulation and connectivity of fecundity and longevity. Here, we used two experimental manipulations to alter queen fecundity in the ant Temnothorax rugatulus and …

Demosponge EST sequencing reveals a complex genetic toolkit of the simplest metazoans.

2010

Sponges (Porifera) are among the simplest living and the earliest branching metazoans. They hold a pivotal role for studying genome evolution of the entire metazoan branch, both as an outgroup to Eumetazoa and as the closest branching phylum to the common ancestor of all multicellular animals (Urmetazoa). In order to assess the transcription inventory of sponges, we sequenced expressed sequence tag libraries of two demosponge species, Suberites domuncula and Lubomirskia baicalensis, and systematically analyzed the assembled sponge transcripts against their homologs from complete proteomes of six well-characterized metazoans--Nematostella vectensis, Caenorhabditis elegans, Drosophila melanog…