scholarly journals Atmospheric CO2 availability induces varying responses in net photosynthesis, toxin production and N2 fixation rates in heterocystous filamentous Cyanobacteria (Nostoc and Nodularia)

2021 ◽  
Vol 83 (2) ◽  
Author(s):  
Nicola Wannicke ◽  
Achim Herrmann ◽  
Michelle M. Gehringer
Keyword(s):  
Nitrogen Availability ◽  
Dark Respiration ◽  
Net Photosynthesis ◽  
Dry Weight ◽  
Toxin Production ◽  
Oxygenic Photosynthesis ◽  
List Type ◽  
Filamentous Cyanobacteria ◽  
Biological Nitrogen ◽  
Stimulation Of

AbstractHeterocystous Cyanobacteria of the genus Nodularia form major blooms in brackish waters, while terrestrial Nostoc species occur worldwide, often associated in biological soil crusts. Both genera, by virtue of their ability to fix N2 and conduct oxygenic photosynthesis, contribute significantly to global primary productivity. Select Nostoc and Nodularia species produce the hepatotoxin nodularin and whether its production will change under climate change conditions needs to be assessed. In light of this, the effects of elevated atmospheric CO2 availability on growth, carbon and N2 fixation as well as nodularin production were investigated in toxin and non-toxin producing species of both genera. Results highlighted the following: Biomass and volume specific biological nitrogen fixation (BNF) rates were respectively almost six and 17 fold higher in the aquatic Nodularia species compared to the terrestrial Nostoc species tested, under elevated CO2 conditions. There was a direct correlation between elevated CO2 and decreased dry weight specific cellular nodularin content in a diazotrophically grown terrestrial Nostoc species, and the aquatic Nodularia species, regardless of nitrogen availability. Elevated atmospheric CO2 levels were correlated to a reduction in biomass specific BNF rates in non-toxic Nodularia species. Nodularin producers exhibited stronger stimulation of net photosynthesis rates (NP) and growth (more positive Cohen’s d) and less stimulation of dark respiration and BNF per volume compared to non-nodularin producers under elevated CO2 levels. This study is the first to provide information on NP and nodularin production under elevated atmospheric CO2 levels for Nodularia and Nostoc species under nitrogen replete and diazotrophic conditions.

Productivity of Vegetable Crops in a Region of High Solar Input. III. Carbon Balance of Potato Crops

1974 ◽  
Vol 1 (2) ◽  
pp. 283 ◽  
Author(s):  
PJM Sale
Keyword(s):  
Carbon Balance ◽  
Dark Respiration ◽  
Net Photosynthesis ◽  
Dry Weight ◽  
Gas Analysis ◽  
Co2 Uptake ◽  
Co2 Efflux ◽  
Vegetable Crops ◽  
Weight Changes ◽  
Potato Crops

The carbon balance of potato crops has been studied by measuring canopy net photosynthesis and dark respiration losses with a field assimilation chamber and semi-closed gas analysis system. Results are given for the latter part of growth in both a spring-planted and a summer-planted crop. Net CO2 uptake increased with solar input to reach 35–40mg dm-2 (ground area) h-1 at 400–450 W m-2, but light saturation then occurred and little or no further uptake resulted from increases in solar input up to 1000 W m-2. This supports the previous conclusion that net photosynthesis in the potato is determined by the size of the 'sink' provided by the developing tubers. The imposed experimental variables of reduced solar input (21 and 34% shade) and soil moisture were found not to affect the relation between solar input and CO2 uptake, and the effect of chamber temperature was also very small. Dark respiration rates of the canopy were markedly sensitive to temperature, and also to the solar input prior to measurement. Respiration from the below-ground plant parts accounted for a considerable part of the total plant respiration. In all, 15–20 % of the net assimilation during daylight hours was lost by night respiration. There was little variation in CO2 efflux from uncropped soil during the experiments. Dry weight changes calculated from the gasometric measurements were in accordance with those found from previous growth analysis. * Part II, Aust. J. Agric. Res., 1973, 24, 751–62.

scholarly journals PHOTOSYNTHESIS, RESPIRATION, AND CARBON COST OF DEVELOPING RABBITEYE BLUEBERRY FRUIT

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1165g-1166
Author(s):  
Keith Birkhold ◽  
Rebecca Darnell ◽  
Karen Koch
Keyword(s):  
Weight Gain ◽  
Fruit Development ◽  
Dark Respiration ◽  
Net Photosynthesis ◽  
Dry Weight ◽  
Total Carbon ◽  
Vaccinium Ashei ◽  
Gross Photosynthesis ◽  
Carbon Cost ◽  
Fruit Photosynthesis

Carbon exchange and content of blueberry (Vaccinium ashei) fruit were measured from anthesis through fruit ripening in order to determine the amount of imported carbon required for fruit development. Net photosynthesis occurred in blueberry fruit from petal fall through color break. During this time, gross photosynthesis of fruit decreased from 30.1 μmol CO2·g fw-1·hr-1 to 4.8 μmol CO2·g fw-1·hr-1, and dark respiration decreased from 14.3 μmol CO2·g fw-1·hr-1 to 4.6 μmol CO2·g fw-1·hr-1. After color break, the photosynthetic rate fell to zero, and the respiration rate increased to 8.0 μmol CO2·g fw-1·hr-1, before decreasing. Preliminary data suggest that fruit photosynthesis contributes 11% of the total carbon required (dry weight gain + respiratory loss) during fruit development however, it supplies 50% of the total carbon required during the first 5 days after petal fall. This contribution of carbon from fruit photosynthesis may be critical in initial fruit development since the current season's vegetative growth is not yet providing carbohydrates.

Circadian rhythms of dark respiration, flowering, net photosynthesis, chlorophyll content, and dry weight changes in Chenopodium rubrum

1972 ◽  
Vol 50 (11) ◽  
pp. 2219-2226 ◽  
Author(s):  
Ah-Sing Chia-Looi ◽  
Bruce G. Gumming
Keyword(s):  
Circadian Rhythms ◽  
Chlorophyll Content ◽  
Dark Respiration ◽  
Net Photosynthesis ◽  
Dry Weight ◽  
Chenopodium Rubrum ◽  
Weight Changes ◽  
Physiological Processes ◽  
Dark Fixation ◽  
Relationship Of

There are circadian rhythmic changes in dark respiration, net photosynthesis, chlorophyll content, and dry weight in Chenopodium rubrum, ecotype 60°47′ N, 137°32′ W. The rhythm in dark respiration has a period of about 27 h and its phasing is quite closely correlated with the rhythm in flowering response, which has a period of about 30 h. A close similarity in the periodicity (21 h) and phasing of the rhythms in net photosynthesis and chlorophyll content suggests that the photosynthetic rhythm may be partly attributed to rhythmic changes in chlorophyll content. The rhythmic changes in dry weight, with a period of 18 h, could be due to a rhythm in dark fixation of carbon dioxide. The possible relationship of rhythmicity in these processes to other circadian rhythms that occur in C. rubrum is discussed. The concurrent existence of various rhythms in biochemical and physiological processes that differ in period and phase within a single ecotype of C. rubrum clearly reflects the possible involvement of metabolic activity in circadian rhythms.

Production, storage, and use of photosynthate during shoot elongation in balsam fir (Abies balsamea)

1973 ◽  
Vol 51 (6) ◽  
pp. 1161-1168 ◽  
Author(s):  
K. Loach ◽  
C. H. A. Little
Keyword(s):  
Dry Matter ◽  
Dark Respiration ◽  
Abies Balsamea ◽  
Net Photosynthesis ◽  
Dry Weight ◽  
Shoot Elongation ◽  
Extension Growth ◽  
Balsam Fir ◽  
Photosynthetic Production ◽  
Intermediate Time

Rates of net photosynthesis and dark respiration of 1-year-old and currently developing foliage were measured in the uppermost (i.e. 1-year-old) whorl of branches of 6-year-old balsam fir trees (Abies balsamea (L.) Mill.) during the period of extension growth of the current shoot. The rates were integrated to estimate net dry matter production by the two ages of foliage, and compared with dry matter requirements for growth of the new shoot (estimated from a regression equation of length over dry weight), and with cambial growth in the 1-year-old shoot (estimated from periodic harvests). The surplus of production over use in these two sinks was stored temporarily in the 1-year-old foliage or exported from the branch, the latter predominating. Two periods in which a large proportion of the photosynthetic production was exported (corresponding roughly to the months of May and July) were separated by a period when export was relatively low. At this intermediate time, current photosynthetic production was minimal and local growth demands were at their highest. Photosynthates stored in the 1-year-old foliage before budbreak supplemented current photosynthesis and permitted export to continue, except for a few days at the end of June. The contribution from stores in the old foliage, however, never exceeded one-third of current photosynthetic production. When extension growth terminated, a second transient storage peak occurred in the 1-year-old foliage for about 2 weeks. These observations explain the commonly observed reduction in root growth during current shoot extension, and corroborate results from studies made by other investigators using radioactive tracers.

Photosynthesis and Respiration of Developing Soybean Pods

1977 ◽  
Vol 4 (5) ◽  
pp. 713 ◽  
Author(s):  
EY Sambo ◽  
J Moorby ◽  
FL Milthorpe
Keyword(s):  
Dark Respiration ◽  
Photochemical Efficiency ◽  
Net Photosynthesis ◽  
Dry Weight ◽  
Daily Basis ◽  
Co2 Uptake ◽  
Response Curves ◽  
Total Import ◽  
Co2 Response ◽  
Gross Photosynthesis

Net CO2 uptake by soybean pods in the light was much less and output in darkness much greater than from equal areas of leaves. The net photosynthesis decreased, becoming negative, and dark respiration increased as seed filling progressed. The photochemical efficiency was the same but the diffusive resistance of pods was about twice and the internal resistance two to three times those of leaves. Fluxes into open deseeded pods were initially much greater than into intact pods but drying out of the tissue soon led to fluxes only about three times greater. From these measurements and light- and CO2-response curves of intact pods, estimates of gross photosynthesis, photorespiration and dark respiration of seeds and hulls were made. These indicated that seed reassimilated slightly more CO2 than they respired when young and about two-thirds thereof at a later stage. Hulls fixed about similar amounts but these were insufficient to prevent net effluxes from pods during the later stages of their development, even at irradiances of 190 W m-2. On a daily basis, direct uptake of CO2 made a negligible contribution to the total import of dry weight by the pod; nevertheless, photosynthesis in the seeds and hulls refixed some 50-70% of the CO2 respired by these tissues.

Photosynthetic Performance of Two Closely Related Umbilicaria Species in Central Spain: Temperature as a Key Factor

1997 ◽  
Vol 29 (1) ◽  
pp. 67-82 ◽  
Author(s):  
L. G. Sancho ◽  
B. Schroeter ◽  
F. Valladares
Keyword(s):  
Water Content ◽  
Dark Respiration ◽  
Net Photosynthesis ◽  
Dry Weight ◽  
Distribution Patterns ◽  
Photon Flux ◽  
Photosynthetic Response ◽  
Central Spain ◽  
Natural Conditions ◽  
Thallus Water Content

AbstractNet photosynthesis (NP) and dark respiration (DR) of thalli of the lichen species Umbilicaria grisea and U. freyi growing together in the same habitat the Sierra de Guadarrama, central Spain, were measured under controlled conditions in the laboratory and under natural conditions in the field over a range of photosynthetic photon flux densities (PPFD), thallus temperatures and thallus water contents. Laboratory experiments revealed that the photosynthetic response to PPFD at optimum thallus water content is very similar in both species. The light compensation points of NP increased from PPFD of c. 20 µmol m−2 s−1 at 0°C up to c. 100 µmol m−2 s−1 PPFD at 25°C. In both species light saturation was not reached up to 700 µmol m−2 s−1 PPFD except at 0°C. By contrast, the temperature dependence of CO2 gas exchange differed substantially between U. grisea and U. freyi. Both species gave significant rates at 0°C. Optimal temperatures of NP were always higher in U. grisea at various PPFD levels if the samples were kept at optimal thallus water content. NP showed maximal rates at 95% dw in U. grisea and 110% dw in U. freyi respectively. In U. grisea a much stronger depression of NP was observed with only 5% of maximal NP reached at 180% dw. At all PPFD and temperature combinations U. freyi showed higher rates of NP and more negative rates of DR if calculated on a dry weight basis. This was also true under natural conditions at the same site, when U. freyi was always more productive than U. grisea. The differences in the photosynthetic response to temperature between both species correlated well with the different distribution patterns of both species. The possibility of genetic control of the physiological performance of these species and its influence on their distribution patterns and autecology is discussed.

scholarly journals Carbon and Nitrogen Economy of Developing Rabbiteye Blueberry Fruit

1992 ◽  
Vol 117 (1) ◽  
pp. 139-145 ◽  
Author(s):  
Keith T. Birkhold ◽  
Karen E. Koch ◽  
Rebecca L. Darnell
Keyword(s):  
Fruit Ripening ◽  
Fruit Development ◽  
Dark Respiration ◽  
Net Photosynthesis ◽  
Dry Weight ◽  
Carbon Dioxide Exchange ◽  
N Content ◽  
Vaccinium Ashei ◽  
Fruit Photosynthesis ◽  
C And N

Carbon dioxide exchange, dry weight, C, and N content of `Bonita' and `Climax' blueberry (Vaccinium ashei Reade) fruit were measured from anthesis through fruit ripening to quantify developmental changes in amounts of imported C and N required for fruit development. Net photosynthesis occurred in fruit of both rabbiteye cultivars from petal fall through color break. During this time, fruit net photosynthesis declined from 16 μmol CO2/g fresh weight (FW) per hour for `Bonita' and 22 μmol CO2/g FW per hour for `Climax' to 0.2 μmol CO2/g FW per hour for both. Dark respiration for both cultivars declined following petal fall from 16 μmol CO2/g FW per hour to 3 μmol CO2/g FW per hour before increasing at fruit ripening to 9 μmol CO2/g FW per hour. Fruit C content was constant at 0.43 mg C/mg dry weight (DW) throughout development, while N content declined from 0.05 mg N/mg DW at petal fall to 0.01 mg N/mg DW at ripeness. DW accumulation and respiration accounted for 63% and 37%, respectively, of the total C requirement for fruit development. Fruit photosynthesis was estimated to contribute 15% of the total C required for fruit development in both cultivars; however, fruit photosynthesis supplied 50% of the C required during the first 10 days after bloom and 85% during the 5 days after petal fall. This large, early contribution of C from fruit photosynthesis may aid in the establishment of fruit until the current season's vegetative growth can supplement plant carbohydrate reserves in providing C for fruit development.

Photosynthesis and dark respiration of black spruce cuttings during rooting in response to light and temperature

1993 ◽  
Vol 23 (6) ◽  
pp. 1150-1155 ◽  
Author(s):  
De Yue ◽  
Hank A. Margolis
Keyword(s):  
Black Spruce ◽  
Dark Respiration ◽  
Net Photosynthesis ◽  
Dry Weight ◽  
Experimental Period ◽  
Photon Flux ◽  
Photosynthetic Rates ◽  
Physiological Quality ◽  
Use Efficiency ◽  
Total Dry Weight

Photosynthesis and dark respiration of semihardened black spruce cuttings (Piceamariana (Mill.) B.S.P.) were periodically measured at a range of light intensities at 10, 15, 20, 25, and 30 °C over an 8-week period in rooting chambers and for 4 additional weeks after the cuttings were transferred to a greenhouse. Increases in the total dry weight of the cuttings over the experimental period were due exclusively to increases in root biomass. The light-saturated photosynthetic rates at 20 °C decreased from 3.8 to 2.2 μmol CO2•m−2•s−1 during the 8 weeks in the rooting chamber. At 15 °C, the light-saturated photosynthetic rate was about 2 μmol CO2•m−2•s−1 and no significant change was observed during the experimental period. Maximum photosynthetic rates were generally attained at photosynthetic photon flux densities (PPFD) of 200–300 μmol•m−2•s−1 At the range of PPFD generally used in rooting chambers (0–50 μmol•m−2•s−1), the light use efficiency of cuttings (net photosynthesis per cutting per PPFD) was greatest at 15 °C. Furthermore, the light compensation point was lowest at 15 °C. The effect of light intensity and temperature on the photosynthesis and dark respiration of cuttings was modelled to predict the carbon balance of cuttings under different conditions of PPFD and temperature. This model should be useful in determining an appropriate set of environmental conditions to use inside rooting chambers and thus improve the overall physiological quality of this type of vegetatively propagated planting stock. The modelling approach described in this study could prove useful for the production of other conifer species by rooted cuttings even when it is conducted using other methods of cultivation (e.g., cold-frames or greenhouses).

Carbon Production and Utilization in Cotton: Inferences From a Carbon Budget

1980 ◽  
Vol 7 (5) ◽  
pp. 539 ◽  
Author(s):  
GA Constable ◽  
HM Rawson
Keyword(s):  
Carbon Budget ◽  
Carbon Fixation ◽  
Dark Respiration ◽  
Net Photosynthesis ◽  
Dry Weight ◽  
General Hypothesis ◽  
Carbon Production ◽  
Single Leaf ◽  
Whole Plant ◽  
Plant Level

A carbon budget for cotton plants at the single leaf, node and whole plant level was constructed using data from four glasshouse experiments. Data were collected on leaf expansion and dry weight growth, net photosynthesis, dark respiration of leaves and stems and on responses of photosynthesis to light in tissues of different age. The potential export of carbon by leaves was calculated as daily net photosynthesis less requirements for growth and dark respiration. The carbon budget for the single leaf showed that the leaf's maximum requirement occurred 7-8 days after unfolding, at the same time as it became a net carbon exporter. Dark respiration used most carbon at days 12-15 but even then the amount was only about 10% of the carbon fixation by the leaf during the day. Potential carbon export reached a peak in 22-day-old leaves, approximating 1 mg C cm-2 day -1 on a sunny day. The main finding from the budget was that carbon production and its utilization by bolls is out of phase both at the node and whole plant level which necessitates considerable movement of carbon among nodes and into and out of storage. This finding was confirmed in a study using 14CO2 which, while supporting the general hypothesis that the plant's carbon is fed into a pool available to all organs, indicated that there are preferred links between node positions in vertical alignment.

scholarly journals PHOTOSYNTHESIS, RESPIRATION, AND CARBON COST OF DEVELOPING RABBITEYE BLUEBERRY FRUIT

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1165G-1166
Author(s):  
Keith Birkhold ◽  
Rebecca Darnell ◽  
Karen Koch
Keyword(s):  
Weight Gain ◽  
Fruit Development ◽  
Dark Respiration ◽  
Net Photosynthesis ◽  
Dry Weight ◽  
Total Carbon ◽  
Vaccinium Ashei ◽  
Gross Photosynthesis ◽  
Carbon Cost ◽  
Fruit Photosynthesis

Carbon exchange and content of blueberry (Vaccinium ashei) fruit were measured from anthesis through fruit ripening in order to determine the amount of imported carbon required for fruit development. Net photosynthesis occurred in blueberry fruit from petal fall through color break. During this time, gross photosynthesis of fruit decreased from 30.1 μmol CO2·g fw-1·hr-1 to 4.8 μmol CO2·g fw-1·hr-1, and dark respiration decreased from 14.3 μmol CO2·g fw-1·hr-1 to 4.6 μmol CO2·g fw-1·hr-1. After color break, the photosynthetic rate fell to zero, and the respiration rate increased to 8.0 μmol CO2·g fw-1·hr-1, before decreasing. Preliminary data suggest that fruit photosynthesis contributes 11% of the total carbon required (dry weight gain + respiratory loss) during fruit development however, it supplies 50% of the total carbon required during the first 5 days after petal fall. This contribution of carbon from fruit photosynthesis may be critical in initial fruit development since the current season's vegetative growth is not yet providing carbohydrates.

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