scholarly journals Shading Effects on Leaf Gas Exchange, Leaf Pigments and Secondary Metabolites of Polygonum minus Huds., an Aromatic Medicinal Herb

Plants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 608
Author(s):  
Fairuz Fatini Mohd Yusof ◽  
Jamilah Syafawati Yaacob ◽  
Normaniza Osman ◽  
Mohd Hafiz Ibrahim ◽  
Wan Abd Al Qadr Imad Wan-Mohtar ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Secondary Metabolites ◽  
Chlorophyll A ◽  
Leaf Gas Exchange ◽  
Photosynthesis Rate ◽  
Total Phenolic ◽  
Chlorophyll B ◽  
Low Light ◽  
Total Anthocyanin ◽  
Polygonum Minus

The growing demand for high value aromatic herb Polygonum minus-based products have increased in recent years, for its antioxidant, anticancer, antimicrobial, and anti-inflammatory potentials. Although few reports have indicated the chemical profiles and antioxidative effects of Polygonum minus, no study has been conducted to assess the benefits of micro-environmental manipulation (different shading levels) on the growth, leaf gas exchange and secondary metabolites in Polygonum minus. Therefore, two shading levels (50%:T2 and 70%:T3) and one absolute control (0%:T1) were studied under eight weeks and 16 weeks of exposures on Polygonum minus after two weeks. It was found that P. minus under T2 obtained the highest photosynthesis rate (14.892 µmol CO2 m−2 s−1), followed by T3 = T1. The increase in photosynthesis rate was contributed by the enhancement of the leaf pigments content (chlorophyll a and chlorophyll b). This was shown by the positive significant correlations observed between photosynthesis rate with chlorophyll a (r2 = 0.536; p ≤ 0.05) and chlorophyll b (r2 = 0.540; p ≤ 0.05). As the shading levels and time interval increased, the production of total anthocyanin content (TAC) and antioxidant properties of Ferric Reducing Antioxidant Power (FRAP) and 2,2-Diphenyl-1-picrylhydrazyl (DPPH) also increased. The total phenolic content (TPC) and total flavonoid content (TFC) were also significantly enhanced under T2 and T3. The current study suggested that P.minus induce the production of more leaf pigments and secondary metabolites as their special adaptation mechanism under low light condition. Although the biomass was affected under low light, the purpose of conducting the study to boost the bioactive properties in Polygonum minus has been fulfilled by 50% shading under 16 weeks’ exposure.

Leaf gas exchange and chlorophyll a fluorescence in soybean leaves infected by Phakopsora pachyrhizi

2017 ◽  
Vol 166 (2) ◽  
pp. 75-85 ◽  
Author(s):  
Vinícius Souza Rios ◽  
Jonas Alberto Rios ◽  
Carlos Eduardo Aucique-Pérez ◽  
Patrícia Ricardino Silveira ◽  
Aline Vieira Barros ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Chlorophyll A ◽  
Chlorophyll A Fluorescence ◽  
Leaf Gas Exchange ◽  
Phakopsora Pachyrhizi ◽  
Soybean Leaves

scholarly journals Production of Bambusa vulgaris seedlings from rhizomes under brackish water irrigation

2020 ◽  
Vol 24 (5) ◽  
pp. 337-342
Author(s):  
Lourenço M. C. Branco ◽  
Claudivan F. de Lacerda ◽  
Albanise B. Marinho ◽  
Carlos H. C. de Sousa ◽  
Amanda S. F. Calvet ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Brackish Water ◽  
Dry Matter ◽  
Leaf Gas Exchange ◽  
Photosynthesis Rate ◽  
Seedling Production ◽  
Randomized Design ◽  
Bambusa Vulgaris ◽  
Completely Randomized Design

ABSTRACT The objective of this study was to evaluate the influence of irrigation with brackish water on the production of bamboo seedlings (Bambusa vulgaris). The experiment was carried out at the Fazenda Experimental Piroás, in the municipality of Redenção, CE, Brazil (4° 14’ 53” S, 38° 45’ 10” W, and altitude of 230 m), in a completely randomized design with five treatments and six repetitions. The treatments consisted of five irrigation water electrical conductivity (ECw): 0.5 (control); 1.5; 2.5; 3.5 and 4.5 dS m-1. At 120 days after the beginning of the application of the treatments the leaf gas exchange, relative chlorophyll index (RCI), plant height (H), shoot dry matter (SDM), H/SDM ratio, and the concentrations of Na+ and K+ in stems and leaves were evaluated. Salt tolerance indexes were calculated based on SDM, H, photosynthesis rate and RCI. The increase in the ECw reduced leaf gas exchange, and the reduction in the photosynthesis rate was caused by stomatal and non-stomatal effects. The salinity affected negatively the growth and quality of bamboo seedlings, with the greatest effects being with ECw equal to or greater than 2.5 dS m-1. Bamboo seedlings present Na+ retention in the stems and low Na+/K+ ratio in the leaves. Bamboo seedlings are tolerant to salinity up to 1.5 dS m-1, indicating that waters with this salinity can be used for seedling production of this species, without loss of growth and quality.

Changes in leaf gas exchange, chlorophyll a fluorescence and antioxidant metabolism within wheat leaves infected by Bipolaris sorokiniana

2016 ◽  
Vol 170 (2) ◽  
pp. 189-203 ◽  
Author(s):  
J.A. Rios ◽  
C.E. Aucique-Pérez ◽  
D. Debona ◽  
L.B.M. Cruz Neto ◽  
V.S. Rios ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Chlorophyll A ◽  
Chlorophyll A Fluorescence ◽  
Leaf Gas Exchange ◽  
Bipolaris Sorokiniana ◽  
Antioxidant Metabolism ◽  
Wheat Leaves

Anthracnose in açaí palm leaves reduces leaf gas exchange and chlorophyll a fluorescence

2016 ◽  
Vol 42 (1) ◽  
pp. 13-20
Author(s):  
Gledson L. S. Castro ◽  
Dalton D. Silva Júnior ◽  
Ana Carolina S. O. Bueno ◽  
Gisele B. Silva
Keyword(s):  
Gas Exchange ◽  
Chlorophyll A ◽  
Chlorophyll A Fluorescence ◽  
Leaf Gas Exchange

scholarly journals Leaf Senescence of Postproduction Poinsettias in Low-light Stress

1994 ◽  
Vol 119 (5) ◽  
pp. 1006-1013 ◽  
Author(s):  
J. Lorene Embry ◽  
Eugene A. Nothnagel
Keyword(s):  
Chlorophyll Fluorescence ◽  
Chlorophyll A ◽  
Light Harvesting ◽  
Light Stress ◽  
Chlorophyll B ◽  
Excitation Spectra ◽  
Low Light ◽  
Fluorescence Excitation ◽  
Fluorescence Excitation Spectra ◽  
Low Light Stress

Photosynthetic light harvesting was investigated under low-light stress conditions relevant to the problem of interior longevity of potted ornamental plants. Comparisons of leaf pigment levels and chlorophyll fluorescence excitation spectra were made for `Gutbier V-10 Amy' poinsettia (Euphorbia pulcherrima Willd.), which has poor interior longevity, and `Eckespoint Lilo' poinsettia, which has superior interior longevity. The results show that `Eckespoint Lilo' had higher total chlorophyll content per leaf area and lower chlorophyll a: chlorophyll b ratio than `Gutbier V-10 Amy'. In low-light stress, `Eckespoint Lilo' retained its chlorophyll or even accumulated higher levels than in high light, while `Gutbier V-10 Amy' did not exhibit higher chlorophyll retention in low light. Both cultivars acclimatized to low-light stress by decreasing the chlorophyll a: chlorophyll b ratio, and this acclimatization was evident sooner in younger, outer-canopy leaves above the pinch than in older leaves below the pinch. Both cultivars also increased the chlorophyll: carotenoid ratio in low light. These changes in pigment composition, which were essentially structural changes, were reflected in functional changes in light harvesting, as assessed by measurements of chlorophyll fluorescence excitation spectra.

scholarly journals Leaf Gas Exchange and Chlorophyll a Fluorescence in Wheat Plants Supplied with Silicon and Infected with Pyricularia oryzae

2014 ◽  
Vol 104 (2) ◽  
pp. 143-149 ◽  
Author(s):  
Carlos Eduardo Aucique Perez ◽  
Fabrício Ávila Rodrigues ◽  
Wiler Ribas Moreira ◽  
Fábio Murilo DaMatta
Keyword(s):  
Gas Exchange ◽  
Chlorophyll A ◽  
Electron Transport Rate ◽  
Leaf Gas Exchange ◽  
Chlorophyll Concentration ◽  
Pyricularia Oryzae ◽  
Gas Exchange Parameters ◽  
Photosynthetic Gas Exchange ◽  
Exchange Performance ◽  
Exchange Parameters

This study investigated the effect of silicon (Si) on the photosynthetic gas exchange parameters (net CO2 assimilation rate [A], stomatal conductance to water vapor [gs], internal CO2 concentration [Ci], and transpiration rate [E]) and chlorophyll fluorescence a parameters (maximum quantum quenching [Fv/Fm and Fv′/Fm′], photochemical [qP] and nonphotochemical [NPQ] quenching coefficients, and electron transport rate [ETR]) in wheat plants grown in a nutrient solution containing 0 mM (–Si) or 2 mM (+Si) Si and noninoculated or inoculated with Pyricularia oryzae. Blast severity decreased due to higher foliar Si concentration. For the inoculated +Si plants, A, gs, and E were significantly higher in contrast to the inoculated –Si plants. For the inoculated +Si plants, significant differences of Fv/Fm between the –Si and +Si plants occurred at 48, 96, and 120 h after inoculation (hai) and at 72, 96, and 120 hai for Fv′/Fm′. The Fv/Fm and Fv′/Fm′, in addition to total chlorophyll concentration (a + b) and the chlorophyll a/b ratio, significantly decreased in the –Si plants compared with the +Si plants. Significant differences between the –Si and +Si inoculated plants occurred for qP, NPQ, and ETR. The supply of Si contributed to decrease blast severity in addition to improving gas exchange performance and causing less dysfunction at the photochemical level.

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