Search results for "ABO"

The Glycerate and Phosphorylated Pathways of Serine Synthesis in Plants : The Branches of Plant Glycolysis Linking Carbon and Nitrogen Metabolism

2018

Serine metabolism in plants has been studied mostly in relation to photorespiration where serine is formed from two molecules of glycine. However, two other pathways of serine formation operate in plants and represent the branches of glycolysis diverging at the level of 3-phosphoglyceric acid. One branch (the glycerate – serine pathway) is initiated in the cytosol and involves glycerate formation from 3-phosphoglycerate, while the other (the phosphorylated serine pathway) operates in plastids and forms phosphohydroxypyruvate as an intermediate. Serine formed in these pathways becomes a precursor of glycine, formate and glycolate accumulating in stress conditions. The pathways can be linked …

2021

The scarcity of transcriptional regulatory genes in Buchnera aphidicola, an obligate endosymbiont in aphids, suggests the stability of expressed gene patterns and metabolic pathways. This observation argues in favor of the hypothesis that this endosymbiont bacteria might contribute little to the host adaptation when aphid hosts are facing challenging fluctuating environment. Finding evidence for the increased expression or silenced genes involved in metabolic pathways under the pressure of stress conditions and/or a given environment has been challenging for experimenters with this bacterial symbiotic model. Transcriptomic data have shown that Buchnera gene expression changes are confined t…

New Insights on the Evolutionary History of Aphids and Their Primary Endosymbiont Buchnera aphidicola

2011

Since the establishment of the symbiosis between the ancestor of modern aphids and their primary endosymbiont,Buchnera aphidicola, insects and bacteria have coevolved. Due to this parallel evolution, the analysis of bacterial genomic features constitutes a useful tool to understand their evolutionary history. Here we report, based on data fromB. aphidicola, the molecular evolutionary analysis, the phylogenetic relationships among lineages and a comparison of sequence evolutionary rates of symbionts of four aphid species from three subfamilies. Our results support previous hypotheses of divergence ofB. aphidicolaand their host lineages during the early Cretaceous and indicate a closer relati…

Changing of the guard: mixed specialization and flexibility in nest defense (Tetragonisca angustula)

2019

Abstract Task allocation is a central challenge of collective behavior in a variety of group-living species, and this is particularly the case for the allocation of social insect workers for group defense. In social insects, both benefits and considerable costs are associated with the production of specialized soldiers. We asked whether colonies mitigate costs of production of specialized soldiers by simultaneously employing behavioral flexibility in nonspecialist workers that can augment defense capabilities at short time scales. We studied colonies of the stingless bee Tetragonisca angustula, a species that has 2 discrete nest-guarding tasks typically performed by majors: hovering guardin…

Effects of peroxidizing herbicides on protoporphyrin IX levels in non-chlorophyllous soybean cell culture

1990

Abstract The mode of action of 16 peroxidizing herbicides belonging to four different families (diphenyl ethers, oxadiazon, pyridine derivatives, and pyrazole derivatives) has been studied in nonchlorophyllous soybean cell cultures. Whenever possible, we have compared active and inactive compounds. Phytotoxic effects were estimated on the basis of growth inhibition, either in the dark or in the light. Protoporphyrin IX accumulations were estimated in dark-treated samples, using a simple methodology. In all cases, we have found a positive correlation between cellular damages and protoporphyrin IX accumulations. The results provide further evidences in favor of the light-dependent activity of…

Intracellular compartmentation and plant cell signalling

1997

Compartmentation is an essential feature of eukaryotic cells, and is crucial for the regulation of cell metabolism. Recent progress has significantly improved the understanding of signal transduction pathways in plants, including the activation of light-signalling networks and the tightly controlled generation of the calcium message. Cell compartmentation is important for the regulation and proliferation of these signalling processes.

Time course analysis of the brain transcriptome during transitions between brood care and reproduction in the clonal raider ant

2017

AbstractDivision of labor between reproductive queens and non-reproductive workers that perform brood care is the hallmark of insect societies. However, the molecular basis of this fundamental dichotomy remains poorly understood, in part because the caste of an individual cannot typically be experimentally manipulated at the adult stage. Here we take advantage of the unique biology of the clonal raider ant,Ooceraea biroi, where reproduction and brood care behavior can be experimentally manipulated in adults. To study the molecular regulation of reproduction and brood care, we induced transitions between both states, and monitored brain gene expression at multiple time points. We found that …

Absorption, translocation and metabolism of pyridate in a tolerant crop (Zea mays) and two susceptible weeds (Polygonum lapathifolium L. and Chenopod…

1988

Summary Absorption, translocation and metabolism of 14C-pyridate were compared in tolerant maize. moderately susceptible Polygonum lapathifolium and susceptible Chenopodium album. Foliar absorption was limited in all species, but comparatively higher penetration levels were observed in younger leaves of dicotyledonous species. The absorbed radioactivity was not very mobile and translocation appeared mainly sym-plastic. Herbicide selectivity could not be explained on the basis of absorption and transport. Chenopodium and P. lapathifolium degraded pyridate and formed unstable water-soluble conjugates that easily released a phytotoxic metabolite. By contrast, more stable unidentified water-sol…

Aspartic Proteinase from Barley Seeds is Related to Animal Cathepsin D

1991

In contrast to the well-characterized mammalian aspartic proteinases, plant aspartic proteinases have received little attention so far. Aspartic proteinase activity has been detected, for example, in resting seeds of scots pine (Salmia et al., 1978), soybean (Bond & Bowles, 1983), barley and wheat (Morris et al., 1985) as well as in leaves of orange (Garcia-Martinez & Moreno, 1986) and barley (Kervinen et al., 1990). Aspartic proteinases have been purified from the seeds of rice (Doi et al., 1980), cucumber, squash (Polanowski et al 1985) and wheat (Dunaevsky et al., 1989) as well as from the leaves of tomato (Rodrigo et al., 1989). The plant aspartic proteinases have been reported to enhan…

Phylogenomics Identifies an Ancestral Burst of Gene Duplications Predating the Diversification of Aphidomorpha

2019

Aphids (Aphidoidea) are a diverse group of hemipteran insects that feed on plant phloem sap. A common finding in studies of aphid genomes is the presence of a large number of duplicated genes. However, when these duplications occurred remains unclear, partly due to the high relatedness of sequenced species. To better understand the origin of aphid duplications we sequenced and assembled the genome of Cinara cedri, an early branching lineage (Lachninae) of the Aphididae family. We performed a phylogenomic comparison of this genome with 20 other sequenced genomes, including the available genomes of five other aphids, along with the transcriptomes of two species belonging to Adelgidae (a close…