Nitrogen supply controls vegetative growth, biomass and nitrogen allocation for grapevine (cv. Shiraz) grown in pots

2015 ◽  
Vol 42 (1) ◽  
pp. 105 ◽  
Author(s):  
Aurélie Metay ◽  
Jessica Magnier ◽  
Nicolas Guilpart ◽  
Angélique Christophe
Keyword(s):  
Vegetative Growth ◽  
Limiting Factor ◽  
Dependent Manner ◽  
Leaf Emergence ◽  
N Supply ◽  
Secondary Axis ◽  
Axis Elongation ◽  
Primary Axis ◽  
N Deficiency ◽  
Area Expansion

Maintaining grapevine productivity with limited inputs is crucial in Mediterranean areas. Apart from water, nitrogen (N) is also an important limiting factor in grape growing. The effects of N deficiency on grapevine growth were investigated in this study. Two-year-old Vitis vinifera L.cv. Shiraz plants grafted on 110 R were grown in pots placed outside and exposed to various N supplies (0, 0.6, 1.2, 2.4 and 12 g plant–1) under well-watered conditions. At veraison, plants were harvested and organs separately dried, weighed and analysed for N. During plant growth, the length of the primary and secondary axes and the number of leaves on them were recorded. The N content of leaves was also analysed at three phenological stages (flowering, bunch closure and veraison). All growth processes were inhibited by N deficiency in an intensity-dependent manner. Quantitative relationships with N supply were established. Vegetative growth responded negatively to N stress when comparing control N supply with no N supply: primary axis elongation (–61%), leaf emergence on the primary axis (–47%), leaf emergence on the secondary axis (–94%) and lamina area expansion (–45%). Significant differences on the plant N status were observed from flowering onwards which might be useful for managing fertilisation.

scholarly journals Optimal Nitrogen Supply Ameliorates the Performance of Wheat Seedlings under Osmotic Stress in Genotype-Specific Manner

Plants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 493 ◽  
Author(s):  
Tania Kartseva ◽  
Anelia Dobrikova ◽  
Konstantina Kocheva ◽  
Vladimir Alexandrov ◽  
Georgi Georgiev ◽  
...  
Keyword(s):  
Osmotic Stress ◽  
Stress Tolerance ◽  
Wheat Variety ◽  
Growth And Yield ◽  
Physiological Status ◽  
Wheat Seedlings ◽  
Modern Variety ◽  
N Supply ◽  
N Assimilation ◽  
N Deficiency

Strategies and coping mechanisms for stress tolerance under sub-optimal nutrition conditions could provide important guidelines for developing selection criteria in sustainable agriculture. Nitrogen (N) is one of the major nutrients limiting the growth and yield of crop plants, among which wheat is probably the most substantial to human diet worldwide. Physiological status and photosynthetic capacity of two contrasting wheat genotypes (old Slomer and modern semi-dwarf Enola) were evaluated at the seedling stage to assess how N supply affected osmotic stress tolerance and capacity of plants to survive drought periods. It was evident that higher N input in both varieties contributed to better performance under dehydration. The combination of lower N supply and water deprivation (osmotic stress induced by polyethylene glycol treatment) led to greater damage of the photosynthetic efficiency and a higher degree of oxidative stress than the individually applied stresses. The old wheat variety had better N assimilation efficiency, and it was also the one with better performance under N deficiency. However, when both N and water were deficient, the modern variety demonstrated better photosynthetic performance. It was concluded that different strategies for overcoming osmotic stress alone or in combination with low N could be attributed to differences in the genetic background. Better performance of the modern variety conceivably indicated that semi-dwarfing (Rht) alleles might have a beneficial effect in arid regions and N deficiency conditions.

scholarly journals Global Expression Profiling and Physiological Characterization of Corynebacterium glutamicum Grown in the Presence of l-Valine

2003 ◽  
Vol 69 (5) ◽  
pp. 2521-2532 ◽  
Author(s):  
C. Lange ◽  
D. Rittmann ◽  
V. F. Wendisch ◽  
M. Bott ◽  
H. Sahm
Keyword(s):  
Corynebacterium Glutamicum ◽  
Expression Profiling ◽  
Large Subunit ◽  
Mrna Level ◽  
Acetohydroxyacid Synthase ◽  
Limiting Factor ◽  
Unexpected Result ◽  
Dependent Manner ◽  
Wild Type ◽  
Concentration Dependent Manner

ABSTRACT Addition of l-valine (50 to 200 mM) to glucose minimal medium had no effect on the growth of wild-type Corynebacterium glutamicum ATCC 13032 but inhibited the growth of the derived valine production strain VAL1 [13032 ΔilvA ΔpanBC(pJC1ilvBNCD)] in a concentration-dependent manner. In order to explore this strain-specific valine effect, genomewide expression profiling was performed using DNA microarrays, which showed that valine caused an increased ilvBN mRNA level in VAL1 but not in the wild type. This unexpected result was confirmed by an increased cellular level of the ilvB protein product, i.e., the large subunit of acetohydroxyacid synthase (AHAS), and by an increased AHAS activity of valine-treated VAL1 cells. The conclusion that valine caused the limitation of another branched-chain amino acid was confirmed by showing that high concentrations of l-isoleucine could relieve the valine effect on VAL1 whereas l-leucine had the same effect as valine. The valine-caused isoleucine limitation was supported by the finding that the inhibitory valine effect was linked to the ilvA deletion that results in isoleucine auxotrophy. Taken together, these results implied that the valine effect is caused by competition for uptake of isoleucine by the carrier BrnQ, which transports all branched-chained amino acids. Indeed, valine inhibition could also be relieved by supplementing VAL1 with the dipeptide isoleucyl-isoleucine, which is taken up by a dipeptide transport system rather than by BrnQ. Interestingly, addition of external valine stimulated valine production by VAL1. This effect is most probably due to a reduced carbon usage for biomass production and to the increased expression of ilvBN, indicating that AHAS activity may still be a limiting factor for valine production in the VAL1 strain.

scholarly journals Microstructural and physiological responses to cadmium stress under different nitrogen levels in Populus cathayana females and males

2020 ◽  
Vol 40 (1) ◽  
pp. 30-45 ◽  
Author(s):  
Miao Liu ◽  
Jingwen Bi ◽  
Xiucheng Liu ◽  
Jieyu Kang ◽  
Helena Korpelainen ◽  
...  
Keyword(s):  
Nitrogen Deficiency ◽  
Ion Homeostasis ◽  
N Availability ◽  
Cd Stress ◽  
Cd Accumulation ◽  
N Supply ◽  
Populus Cathayana ◽  
N Deficiency ◽  
Cellular Compartments ◽  
Cd Translocation

Abstract Although increasing attention has been paid to the relationships between heavy metal and nitrogen (N) availability, the mechanism underlying adaptation to cadmium (Cd) stress in dioecious plants has been largely overlooked. This study examined Cd accumulation, translocation and allocation among tissues and cellular compartments in Populus cathayana Rehder females and males. Both leaf Cd accumulation and root-to-shoot Cd translocation were significantly greater in females than in males under a normal N supply, but they were reduced in females and enhanced in males under N deficiency. The genes related to Cd uptake and translocation, HMA2, YSL2 and ZIP2, were strongly induced by Cd stress in female roots and in males under a normal N supply. Cadmium largely accumulated in the leaf blades of females and in the leaf veins of males under a normal N supply, while the contrary was true under N deficiency. Furthermore, Cd was mainly distributed in the leaf epidermis and spongy tissues of males, and in the leaf palisade tissues of females. Nitrogen deficiency increased Cd allocation to the spongy tissues of female leaves and to the palisade tissues of males. In roots, Cd was preferentially distributed to the epidermis and cortices in both sexes, and also to the vascular tissues of females under a normal N supply but not under N deficiency. These results suggested that males possess better Cd tolerance compared with females, even under N deficiency, which is associated with their reduced root-to-shoot Cd translocation, specific Cd distribution in organic and/or cellular compartments, and enhanced antioxidation and ion homeostasis. Our study also provides new insights into engineering woody plants for phytoremediation.

Crop species present different qualitative types of response to N deficiency during their vegetative growth

2008 ◽  
Vol 105 (3) ◽  
pp. 253-265 ◽  
Author(s):  
Gilles Lemaire ◽  
Erik van Oosterom ◽  
Marie-Hélène Jeuffroy ◽  
François Gastal ◽  
Angelo Massignam
Keyword(s):  
Vegetative Growth ◽  
Crop Species ◽  
N Deficiency

Crop nitrogen demand and canopy area expansion in winter wheat during vegetative growth

2002 ◽  
Vol 16 (4) ◽  
pp. 279-294 ◽  
Author(s):  
Jørgen E. Olesen ◽  
Jørgen Berntsen ◽  
Elly M. Hansen ◽  
Bjørn M. Petersen ◽  
Jens Petersen
Keyword(s):  
Winter Wheat ◽  
Vegetative Growth ◽  
Canopy Area ◽  
Area Expansion ◽  
Nitrogen Demand

scholarly journals Histones Induce the Release of Extracellular Hemoglobin and Red Blood Cell-Derived Microvesicles with Procoagulant Activity

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 2514-2514
Author(s):  
Denis Noubouossie ◽  
Juraj Sokol ◽  
Mark Gerard Piegore ◽  
Anton Ilich ◽  
Michael Wayne Henderson ◽  
...  
Keyword(s):  
Cell Membranes ◽  
Cell Activation ◽  
Calcium Ionophore ◽  
Lipid Vesicles ◽  
Morbidity And Mortality ◽  
Limiting Factor ◽  
Dependent Manner ◽  
Histone Binding ◽  
Extracellular Histones ◽  
Free Plasma

Abstract Background Histones are nuclear proteins that can be released extracellularly following cell death or certain mechanisms of cell activation. Infusion of high doses of histones into mice causes lethality. Circulating levels of extracellular histones are elevated in several disease states associated with inflammation and thrombosis. The mechanisms by which extracellular histones induce morbidity and mortality are not fully understood. Histones may activate or be toxic to several cell types in vitro. Most of these activities have been shown to be dependent on histone signaling through toll-like receptors (TLRs). Red blood cells (RBC) do not express TLRs. However, previous studies have reported that histones promote RBC aggregation, increase shear-dependent RBC fragility, reduce deformability under flow and cause hemolytic anemia in mice. Histones also induce calcium influx and promote PS expression on RBC membranes thereby supporting the prothrombinase activity and shortening clotting times in plasma. Histones may insert into cell membranes (independently of TLRs), and form pore-like structures similar to ionophore. The role of this process in histone-induced RBC toxicity has not been fully investigated. Objective We assessed the ability of individual histones to promote the release of extracellular hemoglobin (Ex-Hb) and RBC-derived microvesicles (RBC-MVs), as well as RBC-MVs' ability to initiate or propagate thrombin generation (TG) in MV-free plasma. Methods RBCs were isolated from citrated whole blood from healthy volunteers, and were re-suspended in buffer with or without 10uM A23187 (calcium ionophore), recombinant histones H2A, H2B, H3 or H4 for 1 hour at 37°C. To assess histone binding, RBCs were washed and dual-stained with fluorophore-conjugated anti-glycophorin A (GPA) and anti-panhistone antibodies. Stained RBCs were analyzed using imaging flow cytometry, and were considered positive for histone binding if the fluorescence intensity was > 95th percentile of RBCs processed in the absence of histones. RBCs were removed by centrifugation at 2,500g for 15 minutes x2. RBC-MVs present in the supernatant were pelleted by centrifugation at 20,000g for 30 min. Isolated RBC-MVs were then re-suspended in buffer to assess PS exposure using the microparticle activity assay (Hyphen Biomed). RBC-MVs were also re-suspended in re-calcified MV-free plasma supplemented with 4uM 41%PC/44%PE/15%PS lipid vesicles to assess their ability to initiate TG by monitoring the activity of thrombin on a fluorogenic substrate over time. To assess their ability to propagate TG, coagulation was initiated by 1pM tissue factor in MV-free plasma containing histone-induced RBC-MVs without addition of synthetic lipid vesicles. In this condition, phospholipids present on the surface of histone-induced RBC-MVs are the limiting factor for TG. The supernatant collected after pelleting RBC-MVs was used to measure Ex-Hb by absorbance at 540 nm. Results The percentage of RBCs positive for histone binding was 21.6%, 2.3%, 76.9% and 98.1% for H2A, H2B, H3 and H4, respectively. Representative images of RBC staining for GPA and histone H4 is shown in Figure 1A. All histone types induced the release of Ex-Hb (Fig. 1B) and RBC-MVs that possess PS activity (Fig. 1C) in a dose-dependent manner, with the highest PS activity observed with H2A. RBC-MVs released by H2A or H2B clearly initiated TG in MV-free normal pool plasma (Fig.1D). They also significantly enhanced TF-initiated TG in the absence of additional lipid vesicles. The release of Ex-Hb and procoagulant RBC-MVs induced by histones were re-capitulated by ionophore to a greater degree, as expected (Fig.1B-E). Conclusions All 4 types of core histones bind to RBCs and induce the release of Ex-Hb. Our findings suggest that despite their lower binding to RBCs, histones H2A and H2B may have a greater ability to induce the release of procoagulant RBC-MVs that can initiate and propagate TG in plasma. The reason for the differential toxicity of histone types on RBCs and the discrepancy between the relative effect of histone-induced RBC-MVs on PS equivalents and TG are unknown. Histone-induced RBC toxicity appears to mimic calcium ionophore, supporting the idea that histones may insert and form functional pores in cell membranes. The contribution of Ex-Hb and procoagulant RBC-MVs to the morbidity and mortality of extracellular histones in vivo requires further studies. Disclosures Monroe: Novo Nordisk A/S: Honoraria, Research Funding.

scholarly journals Temperature and Irradiance Effects on Vegetative Growth of Two Species of Leucocoryne

2003 ◽  
Vol 128 (6) ◽  
pp. 815-820
Author(s):  
J.L. Catley
Keyword(s):  
Vegetative Growth ◽  
Low Temperatures ◽  
Controlled Environment ◽  
Plant Parts ◽  
Leaf Emergence ◽  
Mean Temperature ◽  
Made In

The influences of temperature and irradiance on vegetative growth of two species of Leucocoryne (Leucocoryne coquimbensis F. Phil and L. ixioides (Hook.) Lindl.) were examined in controlled environment growth rooms. The growing environments had day/night temperatures of 10/5, 15/10, or 20/15 °C, providing mean temperatures of 7.5, 12.5, or 17.5 °C, and photosynthetic photon fluxes (PPF) of 497 or 710 μmol·m-2·s-1. Leaf emergence data were recorded up to three times a week, and measurements of vegetative growth were made in the rooms twice weekly. Destructive harvests were carried out at intervals up to four weeks apart. Leaves of L. ixioides emerged first in all mean temperatures. As mean temperature decreased from 17.5 to 7.5 °C, the differences in first emergence dates became more apparent between species. Appearance of the second leaf of both species occurred in less than half the number of days the first leaf took to emerge. The time taken for further leaves to develop increased as temperature decreased, particularly for L. ixioides and at mean temperatures below 12.5 °C. Although leaves of L. ixioides emerged first, days to emergence of further leaves increased to lag behind production of L. coquimbensis leaves, particularly when mean temperatures dropped below 12.5 °C. Temperature also significantly affected growth of other plant parts. As mean temperature increased, maximum leaf, root and main bulb dry weights increased for both species, along with secondary bulb dry weights of L. coquimbensis. As irradiance increased, maximum leaf dry weights decreased and maximum bulb dry weights increased of both species, and maximum dropper dry weights of L. coquimbensis increased. Leucocoryne coquimbensis appears to have the greatest capacity to multiply vegetatively and this is enhanced by high mean temperatures. These results suggest that mean temperatures higher than those used in this study are required for sustained leaf emergence, particularly for L. ixioides although this species has the capacity to emerge at low temperatures. High mean temperatures are also likely to promote vegetative mass of all plant parts of both species, whereas higher irradiance levels than used in this study would enhance main bulb growth.

scholarly journals Inflorescence and Flower Development of the `Hass' Avocado (Persea americana Mill.) during “On” and “Off” Crop Years

1998 ◽  
Vol 123 (4) ◽  
pp. 537-544 ◽  
Author(s):  
Samuel Salazar-García ◽  
Elizabeth M. Lord ◽  
Carol J. Lovatt
Keyword(s):  
Flower Development ◽  
Persea Americana ◽  
High Yield ◽  
Reproductive Condition ◽  
Inflorescence Development ◽  
Apical Buds ◽  
Secondary Axis ◽  
Primary Axis ◽  
Hass Avocado ◽  
Flowering Process

Inflorescence and flower development of the `Hass' avocado (Persea americana Mill.) were investigated at the macro- and microscopic level with three objectives: 1) to determine the time of transition from vegetative to reproductive growth; 2) to develop a visual scale correlating external inflorescence and flower development with the time and pattern of organogenesis; and 3) to quantify the effect of high (“on”) and low (“off”) yields on the flowering process. Apical buds (or expanding inflorescences) borne on summer shoots were collected weekly from July to August during an “on” and “off” crop year. Collected samples were externally described and microscopically analyzed. The transition from vegetative to reproductive condition probably occurred from the end of July through August (end of shoot expansion). During this transition the primary axis meristem changed shape from convex to flat to convex. These events were followed by the initiation of additional bracts and their associated secondary axis inflorescence meristems. A period of dormancy was not a prerequisite for inflorescence development. Continued production of secondary axis inflorescence meristems was observed from August to October, followed by anthesis seven months later. In all, eleven visual stages of bud development were distinguished and correlated with organogenesis to create a scale that can be used to predict specific stages of inflorescence and flower development. Inflorescence development was correlated with minimum temperature ≤15 °C, whereas yield had little effect on the timing of developmental events of individual inflorescence buds. However, the high yield of the “on” year reduced inflorescence number and increased the number of vegetative shoots. No determinate inflorescences were produced during the “on” year. For the “off” year, 3% and 42% of shoots produced determinate and indeterminate inflorescences, respectively.

scholarly journals Regulation Of Endocytosis By Ultrasound And Microbubble Treatment: Potential For Controlled Cellular Delivery Of Drugs To Cancer Cells

2021 ◽  
Author(s):  
Farnaz Fekri
Keyword(s):  
Targeted Delivery ◽  
Intracellular Delivery ◽  
Drug Uptake ◽  
Limiting Factor ◽  
Dependent Manner ◽  
Cellular Delivery ◽  
Plasma Membrane Permeability ◽  
Bulk Fluid ◽  
Biological Barriers ◽  
Endocytic Pathways

The delivery of therapeutics across biological barriers is a limiting factor in achieving ideal pharmacologic responses in patients. Modulating endocytic mechanisms with targeted, clinically-relevant interventions can increase intracellular delivery across biological barriers, and improve the efficacy of drugs. Ultrasound-microbubble (USMB) is a novel targeted delivery strategy that has shown promising potential in both diagnostic and therapeutic applications. The collective behaviour of microbubbles in the acoustic field can increase the plasma membrane permeability of surrounding cells, and enhance the delivery of therapeutics across biological barriers. USMB achieves the intracellular delivery of drugs through sonoporation and modulation of endocytic pathways, but the type of endocytic pathways and the mechanisms of activation were not known. I identified that, under distinct regulations, USMB enhances the rate of both clathrin-mediated endocytosis, as well as a non-receptor-mediated pathway responsible for internalizing bulk fluid into cells. I discovered that lysosome exocytosis and acidsphingomyelinase are required for the regulation of the clathrin-mediated pathway but not fluidphase endocytosis following USMB treatment. Given the potential of the clathrin-independent pathway to form high capacity carries for the uptake of fluids and therapeutics into cells, I aimed to identify the molecular identity of the proteins that drive the formation of non-clathrin coated vesicles following USMB treatment. I established that flotillins contribute to the USMB-induced vesicular uptake of fluid into cells, a phenomenon that depends on palmitoyltransferase DHHC5 and the Src-family kinase Fyn. Furthermore, I confirmed that USMB treatment can enhance the intracellular delivery of chemotherapeutic drugs such as cisplatin, and improve its therapeutic efficacy in a flotillin-dependent manner. This project established that both clathrin-mediated endocytosis and flotillin-dependent endocytosis can be modulated by clinically-relevant USMB treatments to enhance drug uptake and efficacy, revealing an important new strategy for targeted drug delivery in cancer treatment.

scholarly journals Nitrogen deficiency regulates premature senescence by modulating flag leaf function, ROS homeostasis, and intercellular sugar concentration in rice during grain filling

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Shamsu Ado Zakari ◽  
Syed Hassan Raza Zaidi ◽  
Mustapha Sunusi ◽  
Kabiru Dawaki Dauda
Keyword(s):  
Grain Yield ◽  
Leaf Senescence ◽  
Flag Leaf ◽  
Grain Filling ◽  
Sugar Concentration ◽  
Premature Senescence ◽  
N Supply ◽  
Ros Homeostasis ◽  
N Assimilation ◽  
N Deficiency

Abstract Background Leaf senescence occurs in an age-dependent manner, but the rate and timing of leaf senescence may be influenced by various biotic and abiotic factors. In the course of stress, the function, composition, and different components of photosynthetic apparatus occur to be synthesized homogeneously or degraded paradoxically due to different senescence-related processes. Nitrogen (N) deficiency is one of the critical environmental factors that induce leaf senescence, and its incidence may curtail leaf photosynthetic function and markedly alter the genetic information of plants that might result in low grain yield. However, the physiological and genetic mechanism underlying N deficiency regulates premature senescence, and flag leaf function, ROS homeostasis, and intercellular sugar concentration in rice during grain filling are not well understood. In this paper, Zhehui7954 an excellent indica restorer line (wildtype) and its corresponding mutant (psf) with the premature senescence of flag leaves were used to study the effect of different N supplies in the alteration of physiological and biochemical components of flag leaf organ and its functions during grain filling. Results The results showed that the psf mutant appeared to be more susceptible to the varying N supply levels than WT. For instance, the psf mutant showed considerably lower Pn, Chl a, Chl b, and Car contents than its WT. N deficiency (LN) decreased leaves photosynthetic activities, N metabolites, but significantly burst O2•−, H2O2, and relative conductivity (R1/R2) concentrations, which was consistent with the expression levels of senescence-associated genes. Sucrose, glucose, and C/N ratio concentrations increased with a decrease in N level, which was closely associated with N and non-structural carbohydrate translocation rates. Increases in POD activity were positively linked with the senescence-related enhancement of ROS generation under LN conditions, whereas, SOD, CAT, and APX activities showed opposite trends. High N (HN) supply significantly inhibits the transcripts of carbohydrate biosynthesis genes, while N assimilation gene transcripts gradually increased along with leaf senescence. The psf mutant had a relatively higher grain yield under HN treatment than LN, while WT had a higher grain yield under MN than HN and LN. Conclusions This work revealed that the C/N ratio and ROS undergo a gradual increase driven by interlinking positive feedback, providing a physiological framework connecting the participation of sugars and N assimilation in the regulation of leaf senescence. These results could be useful for achieving a higher yield of rice production by appropriate N supply and plant senescence regulation.

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