scholarly journals Interactive effects of high irradiance and moderate heat on photosynthesis, pigments, and tocopherol in the tree-fern Dicksonia antarctica

2009 ◽  
Vol 36 (12) ◽  
pp. 1046 ◽  
Author(s):  
Liubov Volkova ◽  
Michael Tausz ◽  
Lauren T. Bennett ◽  
Erwin Dreyer
Keyword(s):  
Temperature Increase ◽  
Higher Plants ◽  
High Irradiance ◽  
Interactive Effects ◽  
Rubisco Activity ◽  
Tree Fern ◽  
Light Regimes ◽  
Chlorophyll Bleaching ◽  
Xanthophyll Cycle Pigment ◽  
Β Carotene

Effects of high irradiance and moderate heat on photosynthesis of the tree-fern Dicksonia antarctica (Labill., Dicksoniaceae) were examined in a climate chamber under two contrasting irradiance regimes (900 and 170 µmol photons m–2 s–1) and three sequential temperature treatments (15°C; 35°C; back to 15°C). High irradiance led to decline in predawn quantum yield of photochemistry, Fv/Fm (0.73), maximal Rubisco activity (Vcmax; from 37 to 29 µmol m–2s–1), and electron transport capacity (Jmax; from 115 to 67 µmol m–2 s–1). Temperature increase to 35°C resulted in further decreases in Fv/Fm (0.45) and in chlorophyll bleaching of high irradiance plants, while Vcmax and Jmax were not affected. Critical temperature for thylakoid stability (Tc) of D. antarctica was comparable with other higher plants (c. 47°C), and increases of Tc with air temperature were greater in high irradiance plants. Increased Tc was not associated with accumulation of osmotica or zeaxanthin formation. High irradiance increased the xanthophyll cycle pigment pool (V+A+Z, 91 v. 48 mmol mol–1 chlorophyll–1), de-epoxidation state (56% v. 4%), and α-tocopherol. Temperature increase to 35°C had no effect on V+A+Z and de-epoxidation state in both light regimes, while lutein, β-carotene and α-tocopherols increased, potentially contributing to increased membrane stability under high irradiance.

Interactive effects of nitrogen and irradiance on growth and partitioning of dry mass and nitrogen in young tomato plants

2002 ◽  
Vol 29 (11) ◽  
pp. 1319 ◽  
Author(s):  
Corine C. de Groot ◽  
Leo F. M. Marcelis ◽  
Riki van den Boogaard ◽  
Hans Lambers
Keyword(s):  
Leaf Area ◽  
Dry Mass ◽  
High Irradiance ◽  
Interactive Effects ◽  
Tomato Plants ◽  
N Limitation ◽  
N Supply ◽  
N Concentration ◽  
Growth Irradiance ◽  
Dry Mass Partitioning

The interactive effects of irradiance and N on growth of young tomato plants (Lycopersicon esculentum Mill.) were studied. Plants were grown at 70 or 300 μmol photons m–2 s–1, hereafter referred to as 'low' and 'high' irradiance, and at a range of exponential N supply rates (70–370 mg g–1 d–1) or at a constant concentration in the nutrient solution of 12 mM NO3–. At both irradiance levels, leaf area ratio was more important than net assimilation rate (NAR) in explaining effects of N on growth at mild N limitation. However, at severe N limitation, NAR became the most important parameter, as indicated by calculated growth response coefficients. Furthermore, this study shows that N supply and growth irradiance interacted strongly. The decrease of specific leaf area with increasing N limitation and increasing growth irradiance correlated with increasing leaf dry mass percentage and starch concentration. Furthermore, at low irradiance, plants partitioned more dry mass to the stem. Dry mass partitioning to roots increased with decreasing plant N concentration, and this relation appeared to be independent of irradiance. Shading increased plant N concentration and decreased dry mass partitioning to roots. Also, the relationship between plant N concentration and N partitioning to different plant organs was largely independent of growth irradiance.

scholarly journals Comparison of solvent regimes for the extraction of photosynthetic pigments from leaves of higher plants

2004 ◽  
Vol 31 (2) ◽  
pp. 195 ◽  
Author(s):  
Jodie L. Dunn ◽  
Johanna D. Turnbull ◽  
Sharon A. Robinson
Keyword(s):  
Plant Species ◽  
Photosynthetic Pigments ◽  
Relative Efficiency ◽  
Higher Plants ◽  
Full Range ◽  
Aqueous Methanol ◽  
Single Extraction ◽  
Β Carotene ◽  
Single Extractions

The relative efficiency of methanol- and acetone-based solvents for the extraction of pigments from photosynthetic tissues of plant was compared, together with the advantages of multiple versus single extractions. The two commonly employed triple acetone extractions (100 : 80 : 80% and 85 : 100 : 100%) performed comparably for most pigments and for all plant species tested. Single extractions with either 96% methanol or 85% acetone failed to extract the more hydrophobic pigments, especially β-carotene. We conclude that multiple extractions that combine pure and aqueous (80–85%) acetone are preferable for extraction of the full range of pigments. These results suggest that previous studies that have utilised aqueous methanol (especially in a single extraction) have probably underestimated the concentration of β-carotene relative to other pigments.

Conversion of lycopene to β-carotene by plastids isolated from higher plants

1971 ◽  
Vol 10 (9) ◽  
pp. 2051-2058 ◽  
Author(s):  
H.M. Hill ◽  
S.K. Calderwood ◽  
L.J. Rogers
Keyword(s):  
Higher Plants ◽  
Β Carotene

scholarly journals Conversion of lycopene into β-carotene by chloroplasts of higher plants

1969 ◽  
Vol 113 (3) ◽  
pp. 31P-32P ◽  
Author(s):  
H M Hill ◽  
L J Rogers
Keyword(s):  
Higher Plants ◽  
Β Carotene

Cell-free conversion of 1-deoxy-D-xylulose 5-phosphate and 2-C-methyl-D-erythritol 4-phosphate into β-carotene in higher plants and its inhibition by fosmidomycin

1999 ◽  
Vol 40 (14) ◽  
pp. 2743-2746 ◽  
Author(s):  
Monika Fellermeier ◽  
Klaus Kis ◽  
Silvia Sagner ◽  
Ulrich Maier ◽  
Adelbert Bacher ◽  
...  
Keyword(s):  
Higher Plants ◽  
Β Carotene

scholarly journals Interactive Effects of Light and Melatonin on Biosynthesis of Silymarin and Anti-inflammatory Potential in Callus Cultures of Silybum marianum L.

2019 ◽  
Author(s):  
Muzamil Shah ◽  
Muhammad Asad Ullah ◽  
Samantha Drouet ◽  
Muhammad Younas ◽  
Duangjai Tungmunnithum ◽  
...  
Keyword(s):  
Continuous Light ◽  
Biomass Accumulation ◽  
Interactive Effects ◽  
Total Phenolic ◽  
Naphthalene Acetic Acid ◽  
Phytochemical Analysis ◽  
Silybum Marianum ◽  
Light Regimes ◽  
Anti Inflammatory

Silybum marianum L. is a well-known medicinal herb, primarily used in liver protection. Light strongly affects several physiological processes along with secondary metabolites biosynthesis in plants. Herein, S. marianum was exploited for in vitro potential under different light regimes in the presence of melatonin. The optimum callogenic response occurred in combination of 1.0 mg/L α-naphthalene acetic acid and 0.5 mg/L 6-Benzylaminopurine under photoperiod. Continuous light associated with melatonin treatment increased total flavonoid content (TFC), total phenolic content (TPC) and antioxidant potential, followed by photoperiod and dark treatments. The increased level of melatonin has a synergistic effect on biomass accumulation under continuous light and photoperiod, while adverse effect was observed under dark condition. More detailed phytochemical analysis showed maximum total silymarin content (11.92 mg/g DW) when placed under continuous light + 1.0 mg/L melatonin. Individually, the level of silybins (A and B), silydianin, isolsilychristin and silychristin was found highest under continuous light. Anti-inflammatory activities were also studied and highest percent inhibition was recorded against 15-LOX for cultures cultivated under continuous light (42.33%). The current study helps to better understand the influence of melatonin and different light regimes on silymarin production as well as antioxidant and anti-inflammatory activities in S. marianum callus extracts.

scholarly journals Changes in ‘Riviera’ Bermudagrass [Cynodon dactylon (L.) Pers.] Carotenoid Pigments after Treatment with Three p-Hydroxyphenylpyruvate Dioxygenase-inhibiting Herbicides

HortScience ◽  
2011 ◽  
Vol 46 (3) ◽  
pp. 493-498 ◽  
Author(s):  
James T. Brosnan ◽  
Dean A. Kopsell ◽  
Matthew T. Elmore ◽  
Gregory K. Breeden ◽  
Gregory R. Armel
Keyword(s):  
Xanthophyll Cycle ◽  
Cynodon Dactylon ◽  
Application Rate ◽  
Carotenoid Pigment ◽  
Control Programs ◽  
Leaf Tissues ◽  
Pigment Concentrations ◽  
Common Bermudagrass ◽  
Xanthophyll Cycle Pigment ◽  
Β Carotene

Mesotrione, topramezone, and tembotrione are inhibitors of the enzyme p-hydroxyphenylpyruvate dioxygenase (HPPD), which impacts the carotenoid biosynthetic pathway. An experiment was conducted to determine the effects of mesotrione, topramezone, and tembotrione on carotenoid pigment concentrations in common bermudagrass [Cynodon dactylon (L.) Pers.; cv. Riviera] leaf tissues. Bermudagrass plants were treated with three rates of mesotrione (0.28, 0.35, and 0.42 kg·ha−1), topramezone (0.018, 0.025, and 0.038 kg·ha−1), and tembotrione (0.092, 0.184, and 0.276 kg·ha−1). The lowest rate of each herbicide represented the maximum labeled use rate for a single application. Percent visual bleaching was measured at 3, 7, 14, 21, 28, and 35 days after application (DAA). Leaf tissues were sampled on the same dates and assayed for carotenoids. Topramezone and tembotrione bleached bermudagrass leaf tissues to a greater degree than mesotrione. Concomitantly, topramezone and tembotrione also reduced total chlorophyll (chlorophyll a + b), β-carotene, lutein, and total xanthophyll cycle pigment concentrations (zeaxanthin + antheraxanthin + violaxanthin) more than mesotrione. Increases in visual bleaching resulting from application rate were accompanied by linear reductions in lutein, β-carotene, and violaxanthin for all herbicides. Topramezone and tembotrione increased the percentage of zeaxanthin + antheraxanthin in the total xanthophyll pigment pool (ZA/ZAV) 7 days after peak visual bleaching was observed at 14 DAA. Reductions in ZA/ZAV were reported after 21 DAA. This response indicates that sequential applications of topramezone and tembotrione should be applied on 14- to 21-day intervals, because stress induced by these herbicides is greatest at these timings. Increases in photoprotective xanthophyll cycle pigments (ZA/ZAV) at 14 to 21 DAA may be a mechanism allowing bermudagrass to recover from HPPD-inhibiting herbicide injury, because bermudagrass recovered from all treatments by 35 DAA. Data in the current study will allow turf managers to design physiologically validated bermudagrass control programs with HPPD-inhibiting herbicides. Chemical names: mesotrione [2-(4-methysulfonyl-2-nitrobenzoyl)-1,3-cyclohexanedione], tembotrione {2-[2-chloro-4-(methylsulfonyl)-3-[(2,2,2-(trifluoroethoxy)methyl]benzoyl]-1,3-cyclohexanedione}, topramezone {[3-(4,5-dihydro-3-isoxazolyl)-2-methyl-4-(methylsulfonyl)phenyl](5-hydroxy-1-nethyl-1H-pyrazol-4-yl)methanone}.

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