scholarly journals CRISPR/Cas in Arabidopsis: overcoming challenges to accelerate improvements in crop photosynthetic efficiencies

2019 ◽  
Vol 166 (1) ◽  
pp. 428-437 ◽  
Author(s):  
Panupon Khumsupan ◽  
Sophie Donovan ◽  
Alistair J. McCormick
Keyword(s):  
Photosynthetic Efficiencies

Reassessment of Maximum Growth Rates for C3 and C4 Crops

1978 ◽  
Vol 14 (1) ◽  
pp. 1-5 ◽  
Author(s):  
J. L. Monteith
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Growing Season ◽  
Maximum Growth ◽  
Maximum Growth Rate ◽  
Crop Growth ◽  
Close Inspection ◽  
Similar Difference ◽  
Photosynthetic Efficiencies

SUMMARYFigures for maximum crop growth rates, reviewed by Gifford (1974), suggest that the productivity of C3 and C4 species is almost indistinguishable. However, close inspection of these figures at source and correspondence with several authors revealed a number of errors. When all unreliable figures were discarded, the maximum growth rate for C3 stands fell in the range 34–39 g m−2 d−1 compared with 50–54 g m−2 d−1 for C4 stands. Maximum growth rates averaged over the whole growing season showed a similar difference: 13 g m−2 d−1 for C3 and 22 g m−2 d−1 for C4. These figures correspond to photosynthetic efficiencies of approximately 1·4 and 2·0%.

scholarly journals Dark Germination and Seedling Growth in Monocots and Dicots of Different Photosynthetic Efficiencies in 2% and 20.9% O2

1972 ◽  
Vol 49 (2) ◽  
pp. 280-283 ◽  
Author(s):  
G. H. Heichel ◽  
P. R. Day
Keyword(s):  
Seedling Growth ◽  
Photosynthetic Efficiencies

Leaf area development on different shoot types in a young aspen stand and its effect upon production

1970 ◽  
Vol 48 (10) ◽  
pp. 1801-1804 ◽  
Author(s):  
D. F. W. Pollard
Keyword(s):  
Leaf Area ◽  
Total Production ◽  
Short Shoot ◽  
Area Index ◽  
Young Leaves ◽  
Long Shoots ◽  
Short Shoots ◽  
Area Development ◽  
Leaf Area Development ◽  
Photosynthetic Efficiencies

Different shoot types in aspen crowns carried leaves of different ages; leaders continued to produce leaves until early August and always carried some young leaves, whereas short shoots completed development by mid-June. Development of foliage on long shoots was intermediate between that on leaders and short shoots. Leaf area index of the 6-year-old stand reached a maximum of 2.4, of which 2.1 was contributed by short-shoot foliage. The rest was formed by leaders and long shoots. Young leaves on leaders and long shoots were not sufficient to influence total production in the stand appreciably, even though young aspen leaves may have high photosynthetic efficiencies. These young leaves could, however, influence height growth and lateral development of the canopy.

scholarly journals Rotenoid Content of Tephrosia vogelii Leaves Sprayed with Growth Regulators

1969 ◽  
Vol 53 (3) ◽  
pp. 213-220
Author(s):  
Luis E. Gregory ◽  
D. K. Barnes ◽  
R. H. Freyre
Keyword(s):  
Growth Regulators ◽  
Unit Area ◽  
Dry Weight ◽  
Leaf Weight ◽  
Leaf Yellowing ◽  
Tephrosia Vogelii ◽  
Per Se ◽  
Absolute Quantity ◽  
Total Dry Weight ◽  
Photosynthetic Efficiencies

T. volgelii leaves that were yellowed naturally by senescence or artificially by foliar applications of growth regulators showed significant increases in percent total rotenoids per unit of dry leaf weight. The growth regulators that most effectively accelerated leaf-yellowing were dicamba, 2,4,5-T, 2,4,5-TP, and 2,4-D. MH-30, 2,4,6-T amide, 2,6-DA, and 4-CPA failed to induce leaf-yellowing in T. vogelii. Leaf yellowing was accompanied by losses in dry leaf weight per unit area. This was assumed to be caused by the growth regulators lowering photosynthetic efficiencies and increasing metabolic rates, thereby lowering leaf reserves. It is concluded that leafyellowing per se did not change the absolute quantity of rotenoids per leaf; it only altered the ratio of total rotenoids to the total dry weight in a leaf.

scholarly journals Symbiodinium functional diversity and clade specificity under global change stressors

2017 ◽  
Author(s):  
S.W. Davies ◽  
J.B. Ries ◽  
A Marchetti ◽  
Rafaela Granzotti ◽  
K.D. Castillo
Keyword(s):  
Thermal Stress ◽  
Elevated Temperatures ◽  
Transcriptome Profiling ◽  
Photosynthetic Performance ◽  
Molecular Response ◽  
Functional Variation ◽  
Conserved Genes ◽  
Clade C ◽  
Highly Correlated ◽  
Photosynthetic Efficiencies

ABSTRACTCoral bleaching episodes are increasing in frequency, demanding examination of the physiological and molecular responses of corals and their Symbiodinium to climate change. Here we quantify bleaching and Symbiodinium photosynthetic performance of Siderastrea siderea from two reef zones after long-term exposure to thermal and CO2-acidification stress. Molecular response of in hospite Symbiodinium to these stressors was interrogated with RNAseq. Elevated temperatures reduced photosynthetic efficiency, which was highly correlated with bleaching status. However, photosynthetic efficiencies of forereef symbionts were more negatively affected by thermal stress than nearshore symbionts, indicating greater thermal tolerance in nearshore corals. At control temperatures, CO2-acidification had little effect on symbiont physiology, although forereef symbionts exhibited greater photosynthetic efficiencies than nearshore symbionts. Transcriptome profiling revealed that S. siderea were dominated by clade C Symbiodinium, except under thermal stress, which caused shifts to thermotolerant clade D. Comparative transcriptomics of conserved genes across symbiotic partners revealed few differentially expressed Symbiodinium genes when compared to corals. Instead of responding to stress, clade C transcriptomes varied by reef zone, with forereef Symbiodinium exhibiting enrichment of genes associated with photosynthesis. Our findings suggest that functional variation in photosynthetic architecture exists between forereef and nearshore Symbiodinium populations.

Productivity of irrigated pastures following paraplowing and gypsum slotting of subsoil exposed by laser landforming dash a short term study

1988 ◽  
Vol 39 (5) ◽  
pp. 837 ◽  
Author(s):  
SJ Blaikie ◽  
KB Kelly ◽  
WK Mason ◽  
FM Martin
Keyword(s):  
Water Status ◽  
Soil Amelioration ◽  
Pan Evaporation ◽  
Canopy Photosynthesis ◽  
Short Term ◽  
Term Study ◽  
Pasture Production ◽  
Class A ◽  
Short Term Study ◽  
Photosynthetic Efficiencies

The effect of two soil amelioration techniques (paraplow and gypsum-enriched slots) on the productivity of white clover/ryegrass pasture was assessed by monitoring plant and soil water status and canopy gasexchange during an irrigation cycle. The soil was a dense clay, exposed when the topsoil was removed during laser landforming. Pasture growth on such exposed subsoils is very slow.All parameters of soil and plant water status indicated that there was some benefit from amelioration, with slots > paraplow > control. This trend was reflected in canopy photosynthesis. The photosynthetic efficiencies of canopies declined rapidly after 40 mm Class A pan evaporation less rainfall (E- R) in the control and after 50 mm E - R in the paraplowed treatments. At the end of the irrigation cycle (72 mm E - R) the efficiencies of the control and paraplow were about 20% and 50%, respectively, of the wellwatered. The efficiency of the canopy in the slot treatment remained high throughout.Without soil amelioration, pastures grown on exposed subsoil cannot maintain high levels of photosynthesis during a normal irrigation cycle in summer. More frequent irrigation or soil amelioration (or both) are required if pasture production on exposed subsoil is to be dramatically improved.

scholarly journals Scaling-Up and Semi-Continuous Cultivation of Locally Isolated Marine Microalgae Tetraselmis striata in the Subtropical Island of Gran Canaria (Canary Islands, Spain)

Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1326
Author(s):  
Zivan Gojkovic ◽  
Flavio Guidi ◽  
Begoña Bustamante ◽  
Marianna Venuleo ◽  
Patrícia Alexandra Clemente Janeiro de Assunçao ◽  
...  
Keyword(s):  
Large Scale ◽  
Photosynthetic Activity ◽  
Continuous Cultivation ◽  
Scaling Up ◽  
Good Source ◽  
Gran Canaria ◽  
Tetraselmis Striata ◽  
Large Scale Cultivation ◽  
Photosynthetic Efficiencies

The goal of this study was to determine the feasibility of the large-scale cultivation of locally isolated Tetraselmis striata in different open ponds in Gran Canaria. The biomass productivities were 24.66 ± 0.53 kgDW in 32 days (28.9t/ha/year) for 8000 L indoors, 42.32 ± 0.81 kgDW in 43 days (38.8 t/ha/year) for an 8000 L pond outdoors, and 54.9 ± 0.58 kgDW in 28 days (19.6 t/ha/year) for a 45,000 L pond outdoors. The photosynthetic efficiencies were 1.45 ± 0.03% for an 8000 L pond indoors, 1.95 ± 0.04% for 8000 L outdoors. and 1.10 ± 0.01% for a 45,000 L pond outdoors. The selected strain was fast-growing (µ = 0.21 day−1) and could be rapidly scaled up to 45,000 L; it formed healthy cultures that maintained high photosynthetic activity during long-term cultivation and provided stable biomass productivities, able to grow on urea, which acted as a cheap and effective grazer control. The obtained biomass is a good source of proteins and has an FA profile with a high content of some nutritionally important fatty acids: oleic, α-linolenic (ALA) and EPA. The high ash content in the biomass (>35%) can be reduced by the implementation of additional washing steps after the centrifugation of the culture.

Microclimatic variations and their effects on photosynthetic efficiencies and lichen species distribution along elevational gradients in Garhwal Himalayas

2019 ◽  
Vol 28 (8-9) ◽  
pp. 1953-1976 ◽  
Author(s):  
Nayan Sahu ◽  
Shiv Naresh Singh ◽  
Pragya Singh ◽  
Shruti Mishra ◽  
Neha Karakoti ◽  
...  
Keyword(s):  
Species Distribution ◽  
Lichen Species ◽  
Elevational Gradients ◽  
Garhwal Himalayas ◽  
Photosynthetic Efficiencies

Maximizing photosynthetic efficiencies and hydrogen production in microalga cultures

2001 ◽  
pp. 111-130 ◽  
Author(s):  
J. Polle ◽  
S. Kanakagiri ◽  
J.R. Benemann ◽  
A. Melis
Keyword(s):  
Hydrogen Production ◽  
Photosynthetic Efficiencies
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