Abstract Glutamate (Glu) metabolism and amino acid translocation were investigated in the young old leaves of tobacco (Nicotiana tabacum L. cv Xanthi) using [15N]ammonium [2-15N]Glu tracers. Regardless leaf age, assimilation occurred via glutamine synthetase (GS; EC 6.1.1.3) Glu synthase (ferredoxin [Fd]-GOGAT; 1.4.7.1; NADH-GOGAT; 1.4.1.14), both light darkness, it did not depend on dehydrogenase (GDH; 1.4.1.2). The ammonium accumulation patterns support role GDH deamination to provide...

• Processes allowing the recycling of organic nitrogen and export to young leaves seeds are important determinants plant yield, especially when plants nitrate-limited. Because autophagy is induced during leaf ageing in response starvation, its role remobilization was suspected. It recently shown that participates trafficking Rubisco-containing bodies vacuole. To investigate remobilization, several autophagy-defective (atg) Arabidopsis mutants were grown under low high nitrate supplies...

Tomato (Lycopersiconesculentum) seedlings were grown in the presence of cadmium. After 1 week Cd treatment, a sharp decline biomass accumulation leaves and roots was observed, together with decrease rate photosynthetic activity due to both Rubisco chlorophyll degradation stomata closure. Cadmium induced significant nitrate content inhibition activities reductase, nitrite glutamine synthetase (GS) ferredoxin-glutamate synthase. An increase NADH-glutamate synthase dehydrogenase observed...

Five recombinant inbred lines (RILs) of Arabidopsis (Arabidopsis thaliana), previously selected from the Bay-0 × Shahdara RIL population on basis differential leaf senescence phenotypes (from early senescing to late senescing) when cultivated under nitrogen (N)-limiting conditions, were analyzed monitor metabolic markers related N assimilation and remobilization pathways. In each RIL, a decrease total N, free amino acid, soluble protein contents with aging was observed. parallel, expression...

For the first time in Arabidopsis thaliana, this work proposes identification of quantitative trait loci (QTLs) associated with leaf senescence and stress response symptoms such as yellowing anthocyanin-associated redness. When plants were cultivated under low nitrogen conditions, we observed that both old leaves rosette whole redness promoted. Leaf is a symptom related to chlorophyll breakdown. Redness anthocyanin accumulation plant ageing nutrient limitation. In work, used model system...

To investigate the role of stress in nitrogen management plants, effect pathogen attack, elicitors, and phytohormone application on expression two senescence-related markers GS1 (cytosolic glutamine synthetase EC 6.3.1.2) GDH (glutamate dehydrogenase, 1.4.1.2) involved mobilization senescing leaves tobacco (Nicotiana tabacum L.) was studied. The genes primary assimilation such as GS2 (chloroplastic synthetase) Nia (nitrate reductase, 1.6.1.1) also analysed. Glubas gene, coding a...

Abstract Comparison of the extent leaf senescence depending on genetic background different recombinant inbred lines (RILs) Arabidopsis (Arabidopsis thaliana) is described. Five RILs Bay-0 × Shahdara population showing differential phenotypes (from early senescing to late senescing) were selected determine metabolic markers discriminate basis senescence-dependent changes in metabolism. The proportion γ-aminobutyric acid, leucine, isoleucine, aspartate, and glutamate correlated with (1) age...

Summary In this article, we discuss the ways in which our understanding of controls nitrogen remobilisation model species and crop plants have been increased through classical physiological studies use transgenic or mutants with modified capacities for carbon assimilation recycling. An improved transition between recycling will be vital, if improvements efficiency are to reduce need excessive input fertilisers improve stabilise yield. review, present an overall view past work more recent on...

Adaptation to steady-state low-nutrient availability was investigated by comparing the Wassileskija (WS) accession of Arabidopsis thaliana grown on 2 or 10 mM nitrate. Low nitrogen conditions led a limited rosette biomass and seed yield. The latter mainly due reduced number, while weight less affected. However, harvest index lower in high nitrate compared with conditions. Under nitrogen-limiting conditions, reductase activity decreased glutamine synthetase increased higher accumulation...

Nineteen Arabidopsis accessions grown at low (LOW N) and high (HIGH nitrate supplies were labelled using 15N to trace nitrogen remobilization the seeds. Effects of genotype nutrition examined. Nitrate availability affected biomass yield, highly modified concentration in dry remains. Surprisingly, variations one-seed weight (DW1S) harvest index (HI) poorly by nutrition. Nitrogen (NHI) was correlated with HI showed that use efficiency (NUE) increased LOW N. (NRE), as partitioning seeds...

Abstract Autophagy is a fundamental process in the plant life story, playing key role immunity, senescence, nutrient recycling, and adaptation to environment. Transcriptomics metabolomics of rosette leaves Arabidopsis thaliana autophagy mutants (atg) show that essential for cell homeostasis stress responses several metabolic pathways are affected. Depletion hexoses, quercetins, anthocyanins parallel overaccumulation amino acids related compounds, such as glutamate, methionine, glutathione,...

Eighteen accessions of Arabidopsis thaliana were grown with low (N–) and high (N+) nitrogen supply. N uptake was monitored by feeding plants 15N-enriched nutritive solution over 24 h. Biomass [fresh matter (FM) dry (DM)], concentration (N%), 15N content computed to determine the use efficiency (NUE) (NupE). NUE has been estimated as ratio between biomass (DM/N%) NupE in [μg (g−1 DM)]. Accession traits analysed detect common individual genotype features. The genetic variation at input mainly...

Summary Autophagy is present at a basal level in all plant tissues and induced during leaf ageing response to nitrogen ( N ) starvation. Nitrogen remobilization from the rosette seeds impaired autophagy mutants. This report focuses on role of management proteolysis ageing. Metabolites, enzyme activities protein contents were monitored several autophagy‐defective atg Arabidopsis mutants grown under low high nitrate conditions. Results showed that carbon C statuses affected before any...

Glutamine synthetase (EC 6.3.1.2) is a key enzyme of ammonium assimilation and recycling in plants where it catalyses the synthesis glutamine from glutamate. In Arabidopsis, five GLN1 genes encode GS1 isoforms. GLN1;2 most highly expressed leaves over-expressed roots by supply rosettes ample nitrate compared with limiting supply. It shown here that promoter mainly active minor veins flowers and, to lower extent, parenchyma mature leaves. Cytoimmunochemistry reveals protein present companion...

In nature, plants are constantly exposed to many transient, but recurring, stresses. Thus, complete their life cycles, require a dynamic balance between capacities recover following cessation of stress and maintenance memory. Recently, we uncovered new functional role for macroautophagy/autophagy in regulating recovery from heat (HS) resetting cellular memory HS Arabidopsis thaliana. Here, demonstrated that NBR1 (next BRCA1 gene 1) plays crucial as receptor selective autophagy during HS....