Isotopic evidence for nitrogen exchange between autotrophic and heterotrophic tissues in variegated leaves

2016 ◽  
Vol 43 (3) ◽  
pp. 298 ◽  
Author(s):  
Cyril Abadie ◽  
Marlène Lamothe-Sibold ◽  
Françoise Gilard ◽  
Guillaume Tcherkez
Keyword(s):  
Nitrogen Deficiency ◽  
Co2 Assimilation ◽  
Isotopic Labelling ◽  
Nitrogenous Compounds ◽  
Isotopic Methods ◽  
Green Tissue ◽  
White Tissue ◽  
Natural Isotope Abundance ◽  
Nitrogen Exchange ◽  
The One

Many plant species or cultivars form variegated leaves in which blades are made of green and white sectors. On the one hand, there is little photosynthetic CO2 assimilation in white tissue simply because of the lack of functional chloroplasts and thus, leaf white tissue is heterotrophic and fed by photosynthates exported by leaf green tissue. On the other hand, it has been previously shown that the white tissue is enriched in nitrogenous compounds such as amino acids and polyamines, which can, in turn, be remobilised upon nitrogen deficiency. However, the origin of organic nitrogen in leaf white tissue, including the possible requirement for N-reduction in leaf green tissue before export to white tissue, has not been examined. Here, we took advantage of isotopic methods to investigate the source of nitrogen in the white tissue. A survey of natural isotope abundance (δ15N) and elemental composition (%N) in various variegated species shows no visible difference between white and green tissues, suggesting a common N source. However, there is a tendency for N-rich white tissue to be naturally 15N-enriched whereas in the model species Pelargonium × hortorum, white sectors are naturally 15N-depleted, indicating that changes in metabolic composition and/or N-partitioning may occur. Isotopic labelling with 15N-nitrate on illuminated leaf discs clearly shows that the white tissue assimilates little nitrogen and thus relies on nitrate reduction and metabolism in the green tissue. The N-sink represented by the white tissue is considerable, accounting for nearly 50% of total assimilated nitrate.

scholarly journals Symptom Development and Susceptibility of Dwarf Cherry Tomato to Tomato Irregular Ripening, A Fruit Disorder Induced by Silverleaf Whitefly

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 678b-678
Author(s):  
S. Hanif-Khan ◽  
R.C. Bullock ◽  
P.J. Stoffella ◽  
J.K. Brecht ◽  
C.A. Powell ◽  
...  
Keyword(s):  
Lycopersicon Esculentum ◽  
Oviposition Preference ◽  
Silverleaf Whitefly ◽  
Bemisia Argentifolii ◽  
Cherry Tomato ◽  
Symptom Development ◽  
Green Tissue ◽  
White Tissue

Silverleaf whitefly (SLW) (Bemisia argentifolii Bellows and Perring) feeding has been associated with development of tomato irregular ripening (TIR) symptoms. Four dwarf cultivars of cherry tomato (Lycopersicon esculentum L.) were infested with adult SLW to observe oviposition preference, tolerance and TIR symptom development. Oviposition preference was observed at low SLW population. Florida Petite was the most preferred and Micro-Tom the least preferred cultivar, with Florida Lanai and Florida Basket intermediate. Each cultivar exhibited TIR symptoms associated with feeding by the SLW. TIR fruit symptoms were expressed as longitudinal red streaks with yellow, green, pink or red blotches externally, and white, yellow or green tissue internally. External TIR symptoms ranged from 32% (Micro-Tom) to 82% (Florida Basket). However, external symptoms disappeared from 34% (Florida Lanai) to 56% (Micro-Tom) of the fruits during ripening. SLW infested plants had 82% (Florida Lanai) to 99% (Florida Basket) of fruits with internal white tissue regardless of external symptoms. Tomatoes with TIR symptoms rarely ripened to a mature red, and sometimes had empty locules, were smaller in size and were seedless.

AN IRREVERSIBLE GENE-INDUCED PLASTID MUTATION

1949 ◽  
Vol 27c (4) ◽  
pp. 172-178 ◽  
Author(s):  
T. J. Arnason ◽  
G. W. R. Walker
Keyword(s):  
Total Population ◽  
Female Parent ◽  
Single Pair ◽  
Albino Plants ◽  
Plastid Mutation ◽  
Normal Green ◽  
Green Tissue ◽  
White Tissue ◽  
Normal Gene ◽  
Plastid Transmission

When plants of a variegated barley are self-pollinated, they produce few variegated and many albino offspring. In different years the proportion of albino plants has ranged from 80.2 to 93.1% of the total population. Seed from heads having much green tissue gave rise to a much larger proportion of variegated plants than did seed from heads with more white tissue. Maternal inheritance of plastids is probably the cause of this difference. In crosses F1 plants are green, variegated, or albino if the ♂ parent is variegated, but if the ♂ parent is green all the progeny are green. The albino plastids thus apparently do not mutate back to normal in the presence of the normal gene. In some F2 populations deviation from a ratio of 3 green: 1 others is insignificant, in other populations significant deviations, attributed to irregularities of plastid mutation and segregation, occur. F3 results support the hypothesis that a single pair of genes affecting plastids is segregating in hybrids. The normal (green) gene is dominant if "green" proplastids are present in the egg but not dominant if the proplastids are all "white". From cytological observations on sperms and eggs as well as from the genetic results, it is considered likely that direct plastid transmission to zygotes is exclusively from the female parent.

Assessment of the Importance of Nutrient Recycling by Seabirds in the St. Lawrence Estuary

1980 ◽  
Vol 37 (4) ◽  
pp. 583-588 ◽  
Author(s):  
J. Bédard ◽  
J. C. Therriault ◽  
J. Bérubé
Keyword(s):  
Nutrient Recycling ◽  
Vertical Mixing ◽  
Nutrient Budget ◽  
Somateria Mollissima ◽  
Nutrient Regeneration ◽  
Lawrence Estuary ◽  
Nitrogenous Compounds ◽  
The One ◽  
Excretion Rates ◽  
St Lawrence Estuary

Feeding and excretion rates of the herring, great black-backed, and ring-billed gulls (Larus argentatus, L. marinus, and L. delawarensis), and of the common eider (Somateria mollissima) were measured in captive individuals and the concentration of soluble nutrients in their excreta was established.The bird population in a 30.6-km2 coastal study area varied between 2500 and 12 500 individuals between early May and mid-November. These birds excreted a seasonal total of 5.8, 4.2, and 48.1 kg-at. of soluble silicate, phosphate, and nitrogenous compounds, respectively. Such quantities, when introduced in the nutrient budget of the coastal area studied, are found to be negligible, considering the levels of nutrients generally recorded in these waters on the one hand, and the relative importance of alternate sources such as land drainage and vertical mixing on the other. Thus, the seabirds can hardly be viewed, except perhaps under the most special circumstances, as important agents in the dynamic nutrient regeneration processes of marine coastal waters of the St. Lawrence Estuary.Key words: nutrient recycling, seabirds, St. Lawrence Estuary

scholarly journals Ac-induced instability at the Xanthophyllic locus of tomato.

Genetics ◽  
1993 ◽  
Vol 134 (3) ◽  
pp. 931-942
Author(s):  
P W Peterson ◽  
J I Yoder
Keyword(s):  
Marker Gene ◽  
Chromosome Breakage ◽  
Chromosome 10 ◽  
Tomato Plants ◽  
Whole Plant ◽  
Green Tissue ◽  
F1 Progeny ◽  
White Tissue ◽  
Transgenic Tomatoes ◽  
And Control

Abstract To detect genomic instability caused by Ac elements in transgenic tomatoes, we used the incompletely dominant mutation Xanthophyllic-1 (Xa-1) as a whole plant marker gene. Xa-1 is located on chromosome 10 and in the heterozygote state causes leaves to be yellow. Transgenic Ac-containing tomato plants which differed in the location and number of their Ac elements were crossed to Xa-1 tester lines and F1 progeny were scored for aberrant somatic sectoring. Of 800 test and control F1 progeny screened, only four plants had aberrantly high levels of somatic sectors. Three of the plants had twin sectors consisting of green tissue adjacent to white tissue, and the other had twin sectors comprised of green tissue adjacent to tissue more yellow than the heterozygote background. Sectoring was inherited and the two sectoring phenotypes mapped to opposite homologs of chromosome 10; the green/yellow sectoring phenotype mapped in coupling to Xa-1 while the green/white sectoring phenotype mapped in repulsion. The two sectoring phenotypes cosegregated with different single, non-rearranged Acs, and loss of these Acs from the genome corresponded to the loss of sectoring. Sectoring was still observed after transposition of the Ac to a new site which indicated that sectoring was not limited to a single locus. In both sectored lines, meiotic recombination of the sectoring Ac to the opposite homolog caused the phenotype to switch between the green/yellow and the green/white phenotypes. Thus the two different sectoring phenotypes arose from the same Ac-induced mechanism; the phenotype depended on which chromosome 10 homolog the Ac was on. We believe that the twin sectors resulted from chromosome breakage mediated by a single intact, transposition-competent Ac element.

Nitrogen deficiency precludes a growth response to CO2 enrichment in C3 and C4 Panicum grasses

1998 ◽  
Vol 25 (5) ◽  
pp. 627 ◽  
Author(s):  
Oula Ghannoum ◽  
Jann P. Conroy
Keyword(s):  
Growth Response ◽  
Nitrogen Deficiency ◽  
Co2 Enrichment ◽  
Biomass Accumulation ◽  
Dry Mass ◽  
Co2 Assimilation ◽  
Initial Slope ◽  
Co2 Response ◽  
N Supply ◽  
N Deficiency

We investigated the interaction of nitrogen (N) supply and CO2 enrichment on the growth and photosynthesis of Panicum laxum (C3), P. coloratum (C4) and P. antidotale (C4). Plants were grown at ambient CO2 partial pressures (pa) of either 36 (low) or 71 (high) Pa, in potted soil supplied with 0 (low) or 60 (high) mg N kg-1 soil week-1. Elevated CO2 enhanced total plant dry mass of all three species by approximately 28% under high N supply, but had no effect on biomass accumulation under N deficiency. CO2 enrichment resulted in reductions of CO2 assimilation rates (A; measured at comparable pa) of P. laxum, indicating acclimation of photosynthesis. This acclimation, which was more pronounced under N stress, was unrelated to changes in leaf N or non-structural carbohydrate concentrations, because neither were affected by CO2 enrichment. In the C4 grasses grown at low N, A were fully saturated at the current ambient pa, whereas at high N, A increased slightly when CO2 was raised to 71 Pa. N deficiency reduced the initial slope of the CO2 response curve of A in P. antidotale, and this effect was more pronounced at high CO2. In conclusion, the preclusion of a growth response to CO2 enrichment by N deficiency was correlated with a strong inhibition of A in the C3 species, and the saturation of A at below current atmospheric pa in C4 species.

Porphyrinsynthesis in Isolated Particles from Tissue Cultures of Tobacco

1971 ◽  
Vol 26 (9) ◽  
pp. 908-912 ◽  
Author(s):  
Hansjörg A. W. Schneider
Keyword(s):  
Nicotiana Tabacum ◽  
Density Gradient ◽  
Density Gradient Centrifugation ◽  
Gradient Centrifugation ◽  
Tissue Cultures ◽  
Green Tissue ◽  
White Tissue

Particles from green and white tissue cultures of Nicotiana tabacum were fractionated by differential and density gradient centrifugation. Besides mitochondria, microbodies and (broken) chloroplasts particles were found able to metabolize 5-amino-levulinate to porphobilinogen and porphobilinogen to uroporphyrinogen. Succinyl-CoA was not synthetized by them but by mitochondria. The porphyrin forming particles had a density of about 1.21 g/cm3 and were accumulated in fractions between mitochondria (1.19 g/cm3) and microbodies (1.23 g/cm3). Small differencies in density were found between particles from white and green tissue cultures. The data available suggest that the porphyrin synthetizing particles are proplastids or leucoplasts.

scholarly journals The Effect of Foliar Selenium (Se) Treatment on Growth, Photosynthesis, and Oxidative-Nitrosative Signalling of Stevia rebaudiana Leaves

Antioxidants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 72
Author(s):  
Péter Borbély ◽  
Árpád Molnár ◽  
Emil Valyon ◽  
Attila Ördög ◽  
Klára Horváth-Boros ◽  
...  
Keyword(s):  
Plant Biomass ◽  
Foliar Application ◽  
Stem Elongation ◽  
Electron Flow ◽  
Photosynthetic Apparatus ◽  
Stevia Rebaudiana ◽  
Co2 Assimilation ◽  
Stevia Rebaudiana Bertoni ◽  
Protection Mechanisms ◽  
The One

Selenium (Se) enrichment of Stevia rebaudiana Bertoni can serve a dual purpose, on the one hand to increase plant biomass and stress tolerance and on the other hand to produce Se fortified plant-based food. Foliar Se spraying (0, 6, 8, 10 mg/L selenate, 14 days) of Stevia plantlets resulted in slightly decreased stevioside and rebaudioside A concentrations, and it also caused significant increment in stem elongation, leaf number, and Se content, suggesting that foliar Se supplementation can be used as a biofortifying approach. Furthermore, Se slightly limited photosynthetic CO2 assimilation (AN, gsw, Ci/Ca), but exerted no significant effect on chlorophyll, carotenoid contents and on parameters associated with photosystem II (PSII) activity (FV/FM, F0, Y(NO)), indicating that Se causes no photodamage in PSII. Further results indicate that Se is able to activate PSI-cyclic electron flow independent protection mechanisms of the photosynthetic apparatus of Stevia plants. The applied Se activated superoxide dismutase (SOD) isoenzymes (MnSOD1, FeSOD1, FeSOD2, Cu/ZnSOD1, Cu/ZnSOD2) and down-regulated NADPH oxidase suggesting the Se-induced limitation of superoxide anion levels and consequent oxidative signalling in Stevia leaves. Additionally, the decrease in S-nitrosoglutathione reductase protein abundance and the intensification of protein tyrosine nitration indicate Se-triggered nitrosative signalling. Collectively, these results suggest that Se supplementation alters Stevia shoot morphology without significantly affecting biomass yield and photosynthesis, but increasing Se content and performing antioxidant effects, which indicates that foliar application of Se may be a promising method in Stevia cultivation.

Inherent nitrogen deficiency in Pistacia lentiscus preferentially affects photosystem I: a seasonal field study

2011 ◽  
Vol 38 (11) ◽  
pp. 848 ◽  
Author(s):  
Constantinos Nikiforou ◽  
Yiannis Manetas
Keyword(s):  
Electron Flow ◽  
Nitrogen Deficiency ◽  
Co2 Assimilation ◽  
Leaf Nitrogen ◽  
Field Conditions ◽  
Quantum Yields ◽  
Winter Period ◽  
Pistacia Lentiscus ◽  
Total Electron ◽  
Low Nitrogen

Although it is widely documented that CO2 assimilation rates are positively correlated with leaf nitrogen, corresponding studies on a link between this nutrient and photosynthetic light reactions are scarce, especially under natural field conditions. In this investigation, we exploited natural variation in the nitrogen content of mature leaves of Pistacia lentiscus L. (mastic tree) in conjunction with fast chlorophyll a fluorescence rise (the OJIP curves) analysed according to the ‘JIP test’, as this was recently modified to allow for the assessment of events in or around PSI. The results depended on the sampling season, with low nitrogen leaves displaying lower efficiencies for electron flow from intermediate carriers to final PSI acceptors, and lower relative pool sizes of these acceptors, both during the autumn and winter. However, parameters related to the PSII) activity (i.e. quantum yields for photon trapping and electron flow along PSII and the efficiency of a trapped exciton to move an electron from the first plastoquoinone electron acceptor of PSII to intermediate carriers) were limited by low nitrogen only during the winter period. As a result, parameters like the quantum yield of total electron flow along both photosystems as well as the total photosynthetic performance index (PItotal) were positively correlated with leaf nitrogen independently of the season. We conclude that nitrogen deficiency under field conditions preferentially affects PSI activity while the effects on PSII are evident only during the stressful period of the year.

scholarly journals Growth, Mineral Nutrients, Photosynthesis and Related Physiological Parameters of Citrus in Response to Nitrogen Deficiency

Agronomy ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1859
Author(s):  
Wei-Tao Huang ◽  
Yi-Zhi Xie ◽  
Xu-Feng Chen ◽  
Jiang Zhang ◽  
Huan-Huan Chen ◽  
...  
Keyword(s):  
N Uptake ◽  
Nutrient Balance ◽  
Photosynthetic Pigment ◽  
Nitrogen Deficiency ◽  
Photosynthetic Electron Transport ◽  
Dry Weight ◽  
Root Surface ◽  
Co2 Assimilation ◽  
N Concentration ◽  
N Deficiency

Limited data are available on the physiological responses of Citrus to nitrogen (N) deficiency. ‘Xuegan’ (Citrus sinensis (L.) Osbeck) and ‘Shantian pummelo’ (Citrus grandis (L.) Osbeck) seedlings were fertilized with nutrient solution at a N concentration of 0, 5, 10, 15 or 20 mM for 10 weeks. N deficiency decreased N uptake and N concentration in leaves, stems and roots and disturbed nutrient balance and homeostasis in plants, thus inhibiting plant growth, as well as reducing photosynthetic pigment levels and impairing thylakoid structure and photosynthetic electron transport chain (PETC) in leaves, hence lowering CO2 assimilation. The imbalance of nutrients intensified N deficiency’s adverse impacts on biomass, PETC, CO2 assimilation and biosynthesis of photosynthetic pigments. Citrus displayed adaptive responses to N deficiency, including (a) elevating the distributions of N and other elements in roots, as well as root dry weight (DW)/shoot DW ratio and root-surface-per-unit volume and (b) improving photosynthetic N use efficiency (PNUE). In general, N deficiency had less impact on biomass and photosynthetic pigment levels in C. grandis than in C. sinensis seedlings, demonstrating that the tolerance of C. grandis seedlings to N deficiency was slightly higher than that of C. sinensis seedlings, which might be related to the higher PNUE of the former.

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