scholarly journals End-product Inhibition of Photosynthesis in Prunus cerasus L. in Response to Whole-plant Source-Sink Manipulation

1995 ◽  
Vol 120 (4) ◽  
pp. 583-599 ◽  
Author(s):  
Desmond R. Layne ◽  
J.A. Flore
Keyword(s):  
Chlorophyll Fluorescence ◽  
Chlorophyll Content ◽  
Feedback Inhibition ◽  
Photochemical Efficiency ◽  
Sour Cherry ◽  
Product Inhibition ◽  
Prunus Cerasus ◽  
Soluble Carbohydrates ◽  
Regeneration Rate ◽  
Source Sink

The source-sink ratio of l-year-old, potted `Montmorency' sour cherry (Prunus cerasus) trees was manipulated by partial defoliation (D) or continuous lighting (CL) to investigate the phenomenon of end-product inhibition of photosynthesis. Within 24 hours of D, net CO2 assimilation rate (A) of the most recently expanded source leaves of D plants was significantly higher than nondefoliated (control) plants throughout the diurnal photoperiod. Between 2 and 7 days after D, A was 30% to 50% higher and stomatal conductance rate (g,) was 50% to 100% higher than in controls. Estimated carboxylation efficiency(k) and ribulose-1,5-bisphosphate (RuBP) regeneration rate increased significantly within 2 days and remained consistently higher for up to 9 days after D. Leaf starch concentration and dark respiration rate decreased but sorbitol and sucrose concentration increased after D. The diurnal decline in A in the afternoon after D may have been due to feedback inhibition from accumulation of soluble carbohydrates (sucrose and sorbitol) in the cytosol. This diurnal decline indicated that trees were sink limited. By 9 days after D, photochemical efficiency was significantly higher than in control plants. In the long term, leaf senescence was delayed as indicated by higher A and gs in combination with higher chlorophyll content up to 32 days after D. CL resulted in a significant reduction of A, gs, k, variable chlorophyll fluorescence (Fv), photochemical efficiency, and estimated RuBP regeneration rate of the most recently expanded source leaves within 1 day. During the exposure to CL, A was reduced 2- to 3-fold and k was reduced up to 4-fold. The normal linear relationship between A and gs was uncoupled under CL indicating that A was not primarily limited by gs and since internal CO2 concentration was not significantly affected, the physical limitation to A imposed by the stomata was negligible. The decrease in Fv and photochemical efficiency indicated that leaves were photoinhibited within 1 day. The decrease in instantaneous chlorophyll fluorescence after at least 1 day of CL indicated that there was a reversible regulatory mechanism whereby the damage to photosystem II reaction centers was repaired. Leaf chlorophyll content was not altered by 1,2, or 3 days of exposure to CL, indicating that photooxidation of chlorophytl did not occur. The time to full photosynthetic recovery from CL increased as the duration of exposure increased. CL plants that were photoinhibited accumulated significant starch in the chloroplast in a companion study (Layne and Flore, 1993) and it is possible that an orthophosphate limitation in the chloroplast stroma was occurring. D plants that were continuously illuminated were not photosynthetically inhibited. After 7 days of CL, plants that were then partially defoliated yet remained in CL photosynthetically recovered within 5 days to pre-CL values. Under the conditions of this investigation, end-product inhibition of A occurred in young, potted sour cherry trees but the mechanism of action in D plants was different than in CL plants.

scholarly journals Photosynthetic behaviour during the leaf ontogeny of rubber tree clones[Hevea brasiliensis (Wild. ex. Adr. de Juss.) Muell. Arg.], in Lavras, MG

2007 ◽  
Vol 31 (1) ◽  
pp. 91-97 ◽  
Author(s):  
Aurélio Antas Miguel ◽  
Luiz Edson Mota de Oliveira ◽  
Paulo Araquém Ramos Cairo ◽  
Davi Melo de Oliveira
Keyword(s):  
Chlorophyll Fluorescence ◽  
Stomatal Conductance ◽  
Chlorophyll Content ◽  
Rubber Tree ◽  
Leaf Age ◽  
Photochemical Efficiency ◽  
Net Photosynthesis ◽  
Leaf Ontogeny ◽  
Chlorophyll Contents ◽  
Internal Co2

This work proposed to investigate changes in the photosynthetic behavior during the leaf ontogeny of the during the leaf development. Up to the 32nd day of leaf age (stage B2), the net photosynthesis was negative due to the inefficiency of the photosynthetic system, and this fact was justified by the following factors: low chlorophyll content, less stomatal conductance, high rubber tree clones PB 235, RRIM 600 and GT 1, in Lavras, MG. The experiment was performed in 2004, between May and July, under field conditions, at the Universidade Federal de Lavras. During the leaf ontogeny, the following characteristics were evaluated: chlorophyll content, gaseous exchanges and chlorophyll fluorescence. The clones presented similar profiles of alterations in the physiological characteristics internal CO2 levels and low chlorophyll fluorescence. From the 37th day of leaf age, net photosynthesis became positive and gradually higher, stimulated by the increases in the chlorophyll contents, photochemical efficiency of photosystem II, carboxylation efficiency, stomatal conductance, transpiration and water use efficiency. Among the clones, photosynthetic behavior was similar, reaching maximum performance on the 57th day of leaf age (stage D), when clone RRIM 600 showed the highest net photosynthesis, differing from the clones PB 235 and GT 1.

Detection of Heterodera schachtii infestation in sugar beet by means of laser-induced and pulse amplitude modulated chlorophyll fluorescence

Nematology ◽  
2006 ◽  
Vol 8 (2) ◽  
pp. 273-286 ◽  
Author(s):  
Sebastian Kiewnick ◽  
Walter Kühbauch ◽  
Astrid Schmitz ◽  
Iryna Tartachnyk ◽  
Richard Sikora
Keyword(s):  
Chlorophyll Fluorescence ◽  
Sugar Beet ◽  
Chlorophyll Content ◽  
Chlorophyll Concentration ◽  
Photochemical Efficiency ◽  
Pulse Amplitude ◽  
Heterodera Schachtii ◽  
Gas Exchange Parameters ◽  
Linear Discrimination ◽  
Leaf Chlorophyll

AbstractTwo glasshouse experiments with sugar beet cvs Penta and Macarena inoculated, respectively, with 0 or 1500 and 0, 500, 1000 or 1500 juveniles of Heterodera schachtii, were conducted to estimate the capability of laser-induced chlorophyll fluorescence (LIF) and pulse amplitude modulated (PAM) chlorophyll fluorescence techniques to detect H. schachtii infestation and to differentiate between infestation levels. Fluorescence and gas exchange parameters, nitrogen and chlorophyll content of sugar beet leaves were measured weekly after nematode inoculation. Sugar beet plants responded to H. schachtii infestation initially with a decrease in photosynthesis rate and later with a reduction in nitrogen uptake and chlorophyll concentration. At the early stages of nematode infestation, before visual symptoms were evident, infested sugar beet plants displayed increased fluorescence (F680, F740). Later stages of infection were accompanied by an increase in the F686/F740 ratio, ground fluorescence (Fo) and a decrease in photochemical efficiency (Fv/Fm) induced by degradation of leaf chlorophyll. Sugar beet plants infested with 500, 1000 or 1500 juveniles per 100 cm3 of soil did not differ either in their nitrogen and chlorophyll content or in photosynthesis and transpiration rate. The linear discrimination analysis based on the combination of PAM and LIF parameters resulted in 100% correct classification of control plants and high classification rates (60-100%) of the infested treatments on all the sampling dates. Whether the fluorescence technique will differentiate nematode densities under field conditions needs further study.

Photoperiod has a stronger impact than irradiance on the source–sink relationships in the sink-limited species Erythronium americanum

Botany ◽  
2011 ◽  
Vol 89 (11) ◽  
pp. 763-770 ◽  
Author(s):  
Anthony Gandin ◽  
Pierre Dizengremel ◽  
Line Lapointe
Keyword(s):  
Feedback Control ◽  
Net Photosynthetic Rate ◽  
Photosynthetic Rate ◽  
Feedback Inhibition ◽  
Photochemical Efficiency ◽  
Biomass Accumulation ◽  
Growth Season ◽  
Erythronium Americanum ◽  
Source Sink ◽  
Long Photoperiod

Under sink-limited conditions, source activity is modulated to remain in balance with the use of carbohydrates by the sink, but this feedback control has been studied in only a few systems so far. Sink and source activities were investigated throughout the season. Plants were subjected to two photoperiod regimes combined with two irradiance levels to produce three different daily amounts of photons. Net photosynthetic rate and the photochemical efficiency of photosynthesis were initially higher under a long photoperiod, but decreased early in the growth season, whereas they remained fairly constant until a few days before leaf senescence under a short photoperiod. The rates of starch and biomass accumulation in the bulb were also faster under a long photoperiod at the beginning of the season but reached similar levels under both short and long photoperiods later on. Response to photoperiod cannot be explained by changes in daily amounts of photons, as none of the variables reported were affected by instantaneous or daily irradiance. It appears that the total amount of carbohydrate synthesized under a long photoperiod was in excess compared to the ability of the sink to store or use them, inducing a feedback inhibition of net photosynthetic rate to restore the source–sink balance.

scholarly journals The importance of bee pollination of the sour cherry (Prunus cerasus) Cultivar "Stevnsbaer" in Denmark

2012 ◽  
Vol 10 ◽  
Author(s):  
Lise Hansted ◽  
Brian W.W. Grout ◽  
Jergen Eilenberg ◽  
Ivar B. Dencker ◽  
Torben B. Todam-Andersen
Keyword(s):  
Sour Cherry ◽  
Prunus Cerasus ◽  
Bee Pollination

scholarly journals Large variations in antioxidant capacity and contents of Hungarian sour and sweet cherry cultivars

2010 ◽  
Vol 16 (3) ◽  
Author(s):  
N. Papp ◽  
J. Nyéki ◽  
Z. Szabó ◽  
É. Stefanovits-Bányai ◽  
T. Szabó ◽  
...  
Keyword(s):  
Antioxidant Capacity ◽  
Sweet Cherry ◽  
Consumer Preferences ◽  
Phenotypic Variability ◽  
Sour Cherry ◽  
Prunus Cerasus ◽  
Nutritional Requirements ◽  
Total Anthocyanin ◽  
Local Origin ◽  
Sweet Cherry Cultivars

Sour cherry (Prunus cerasus L.) cultivars grown in Hungary are of local origin while most sweet cherry cultivars in Hungary are introduced from other countries.A great phenotypic variability is displayed by both species. In the present study, we analyzed 10 sour and 9 sweet cherry cultivars for their antioxidant capacity, total polyphenolics (TPC) and total anthocyanin (TMAC) contents. In general, sour cherries showed higher levels of antioxidant capacity, TPC and TMAC. The anthocyanin contents varied from 0.16 to 6.85 and 1.41 to 127.56 mg/100 g for sweet and sour cherries, respectively. However, TMAC generally seems to have a limited influence on the antioxidant capacity of cherries.An amarelletype sour cherry, ‘Pipacs 1’ showed the highest antioxidant capacity (21.21mmolAA/l) and TPC (44.07mgGA/l) in contrast to its lowanthocyanin content. The detected diversity presents a choice that can satisfy different consumer preferences, and meet specific nutritional requirements.

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