Abstract Reactive oxygen species and redox signaling undergo synergistic antagonistic interactions with phytohormones to regulate protective responses of plants against biotic abiotic stresses. However, molecular insight into the nature this crosstalk remains scarce. We demonstrate that hydrogen peroxide–responsive UDP-glucosyltransferase UGT74E2 Arabidopsis thaliana is involved in modulation plant architecture water stress response through its activity toward auxin indole-3-butyric acid...

Yield and quality improvement of bread wheat (Triticum aestivum) is a focus in efforts to meet new demands from population growth changing human diets. As the complexity genome unravelled, determining how it used build protein machinery plants key next step explaining detailed aspects development. The specific functions organs during vegetative development role metabolism, degradation remobilisation driving grain production are foundations crop performance have recently become accessible...

Summary Plant asparaginyl endopeptidases ( AEP s) are expressed as inactive zymogens that perform maturation of seed storage protein upon cleavage‐dependent autoactivation in the low‐ pH environment vacuoles. The s have attracted attention for their macrocyclization reactions, and been classified cleavage or ligation specialists. However, we recently shown ability to produce either cyclic acyclic products can be altered by mutations active site region, several capable given favorable...

Malate and citrate underpin the characteristic flexibility of central plant metabolism by linking mitochondrial respiratory with cytosolic biosynthetic pathways. However, identity carrier proteins that influence both processes has remained elusive. Here we show a systems approach DICARBOXYLATE CARRIER 2 (DIC2) facilitates malate-citrate exchange in vivo Arabidopsis thaliana. DIC2 knockout (dic2-1) retards growth vegetative tissues. In vitro organello analyses demonstrate preferentially...

Mitochondria complex II (succinate dehydrogenase, SDH) plays a central role in respiratory metabolism as component of both the electron transport chain and tricarboxylic acid cycle. We report identification an SDH assembly factor by analysis T-DNA insertions At5g51040, protein with unknown function that was identified mass spectrometry low abundance mitochondrial protein. This gene is co-expressed number genes encoding proteins, including SDH1-1, has partial sequence similarity to human...

Mitochondrial malate dehydrogenase (mMDH; EC 1.1.1.37) has multiple roles; the most commonly described is its catalysis of interconversion and oxaloacetate in tricarboxylic acid cycle. The roles mMDH Arabidopsis (Arabidopsis thaliana) seed development germination were investigated mMDH1 mMDH2 double knockout plants. A significant proportion mmdh1mmdh2 seeds nonviable developed only to torpedo-shaped embryos, indicative arrested embryo growth during embryogenesis. viable had an impaired...

Glutaredoxins (Grxs) are small proteins that function as oxidoreductases with roles in deglutathionylation of proteins, reduction antioxidants, and assembly iron-sulfur (Fe-S) cluster-containing enzymes. Which the 33 Grxs Arabidopsis (Arabidopsis thaliana) perform Fe-S mitochondria is unknown. We have examined detail monothiol GrxS15 plants. Our results show its exclusive mitochondrial localization, we concluding it major or only Grx this subcellular location. Recombinant has a very low...

Sugar metabolism and the oxidative pentose phosphate pathway (OPPP) are strongly implicated in N assimilation, although relationship between them roles of plastidial cytosolic OPPP have not been established genetically. We studied a knock-down mutant plastid-localized enzyme 6-phosphogluconolactonase 3 (PGL3). pgl3-1 plants exhibited relatively greater resource allocation to roots but were smaller than wild type. They had lower content amino acids free NO3 - leaves type, despite exhibiting...

Summary Mitochondrial Lon1 loss impairs oxidative phosphorylation complexes and TCA enzymes causes accumulation of specific mitochondrial proteins. Analysis over 400 protein degradation rates using 15 N labelling showed that 205 were significantly different between wild type ( WT ) lon1‐1 . Those proteins included ribosomal proteins, electron transport chain subunits enzymes. For respiratory I V, decreased abundance correlated with higher rate in total extracts. After blue native separation,...

Protein homeostasis in eukaryotic organelles and their progenitor prokaryotes is regulated by a series of proteases including the caseinolytic protease (CLPP). CLPP has essential roles chloroplast biogenesis maintenance, but significance plant mitochondrial remains unknown factors that aid coordination nuclear- mitochondrial-encoded subunits for complex assembly mitochondria await discovery. We generated knockout lines single gene CLP subunit, CLPP2, Arabidopsis (Arabidopsis thaliana)....

Phosphite () induces a range of physiological and developmental responses in plants by disturbing the homeostasis macronutrient phosphate. Because its close structural resemblance to phosphate, phosphite impairs sensing, membrane transport, subcellular compartmentation In addition, plant defence an as yet unknown mode action. this study, acclimation Arabidopsis thaliana sustained supply growth medium was investigated compared with growing under varying phosphate supplies. Unlike did not...

Abiotic stress in plants causes accumulation of reactive oxygen species (ROS) leading to the need for new protein synthesis defend against ROS and replace existing proteins that are damaged by oxidation. Functional plant ribosomes critical these activities, however we know little about impact oxidative on ribosome abundance, turnover, function. Using Arabidopsis cell culture as a model system, induced using 1 µm H2 O2 or 5 menadione more than halve growth rate limit total content. We show...

In reverse genetic knockout (KO) studies that aim to assign function specific genes, confirming the reduction in abundance of encoded protein will often aid link between genotype and phenotype. However, measuring is particularly difficult plant research, where only a limited number antibodies are available. This problem enhanced when studying gene families or different proteins derived from same (isoforms), as many cross react with more than one protein. We show utilizing selected reaction...

Summary Leaf respiration in the dark ( R ) is often measured at a single time during day, with hot‐acclimation lowering common measuring temperature. However, it unclear whether diel cycle influences extent of thermal acclimation , or how temperature and day interact to influence respiratory metabolites. To examine these issues, we grew rice under 25°C : 20°C, 30°C 40°C 35°C night cycles, changes metabolites five points spanning 24‐h period. differed among treatments day. there was no...

Succinate dehydrogenase (SDH, complex II), which plays an essential role in mitochondrial respiration and tricarboxylic acid metabolism, requires the assembly of eight nuclear-encoded subunits insertion various cofactors. Here, we report on characterization Arabidopsis thaliana leucine-tyrosine-arginine (LYR) protein family member SDHAF1, (At2g39725) is a factor required for SDH activity. SDHAF1 located mitochondria can fully complement yeast deletion strain. Knockdown using RNA interference...

Multiple studies have shown ribulose-1,5-bisphosphate carboxylase/oxygenase (E.C. 4.1.1.39; Rubisco) to be subject Lys-acetylation at various residues; however, opposing reports exist about the biological significance of these post-translational modifications. One aspect that has not been addressed in plants generally, or with Rubisco specifically, is stoichiometry which events occur. As a method ascertain sites on Arabidopsis might regulatory importance its catalytic function Calvin-Benson...

SUMMARY Autophagy is a conserved catabolic process that plays an essential role under nutrient starvation conditions and influences different developmental processes. We observed seedlings of autophagy mutants ( atg2 , atg5 atg7 atg9 ) germinated in the dark showed delayed chloroplast development following illumination. The was characterized by decrease photosynthetic chlorophyll biosynthetic proteins, lower content, reduced size, increased levels proteins involved lipid biosynthesis....

Summary Determining which proteins are actively synthesized at a given point in time and extracting representative sample for analysis is important to understand plant responses. Here we show that the methionine (Met) analogue homopropargylglycine (HPG) enables Bio‐Orthogonal Non‐Canonical Amino acid Tagging (BONCAT) of small being Arabidopsis plants or cell cultures, facilitating their click‐chemistry enrichment analysis. The sites HPG incorporation could be confirmed by peptide mass...

Abstract Plant asparaginyl endopeptidases (AEPs) are expressed as inactive zymogens that perform seed storage protein maturation upon cleavage dependent auto-activation in the low pH environment of vacuoles. AEPs have attracted attention for their macrocyclization reactions and been classified or ligation specialists. However, we recently shown ability to produce either cyclic acyclic products can be altered by mutations active site region, several capable given favorable conditions. One AEP...

Autophagy is a catabolic process facilitating the degradation of cytoplasmic proteins and organelles in lysosome- or vacuole-dependent manner plants, animals, fungi. Proteomic studies have demonstrated that autophagy controls shapes proteome has identified both receptor cargo inside autophagosomes. In smaller selection studies, proteomics been used for analysis post-translational modifications target elimination protein–protein interactions between receptors cargo, providing better...

ABSTRACT Malate is the major substrate for respiratory oxidative phosphorylation in illuminated leaves. In mitochondria malate converted to citrate either replenishing tricarboxylic acid (TCA) cycle with carbon, or be exported as cytosolic biosynthetic pathways storage vacuole. this study, we show that DIC2 functions a mitochondrial malate/citrate carrier vivo Arabidopsis. knockout ( dic2-1 ) results growth retardation can only restored by expressing but not its closest homologs DIC1 DIC3,...

Abstract Protein homeostasis in eukaryotic organelles and their progenitor prokaryotes is regulated by a series of proteases including the caseinolytic protease (CLPP). CLPP has essential roles chloroplast biogenesis maintenance, but significance plant mitochondrial remains unknown factors that aid coordination nuclear encoded subunits for complex assembly mitochondria await discovery. We generated knock-out lines single gene CLP subunit, CLPP2, Arabidopsis thaliana . Mutants had higher...