scholarly journals Impact of Elevated CO2 on Leaf Gas Exchange, Carbohydrates and Secondary Metabolites Accumulation in Labisia pumila Benth

2017 ◽  
Vol 19 (6) ◽  
pp. 1-16
Author(s):  
Mohd Ibrahim ◽  
Hawa Jaafar ◽  
Nurul Zain
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 ◽  
...  

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.


1998 ◽  
Vol 140 (2) ◽  
pp. 185-196 ◽  
Author(s):  
PHILIPP EGLI ◽  
STEFAN MAURER ◽  
MADELEINE S. GUNTHARDT-GOERG ◽  
CHRISTIAN KORNER

2002 ◽  
Vol 29 (12) ◽  
pp. 1377 ◽  
Author(s):  
Katharina Siebke ◽  
Oula Ghannoum ◽  
Jann P. Conroy ◽  
Susanne von Caemmerer

This study investigates the effect of elevated CO2 partial pressure (pCO2)-induced stomatal closure on leaf temperature and gas exchange of C4 grasses. Two native Australian C4 grasses, Astrebla lappacea (Lindl.) Domin and Bothriochloa bladhii Kuntze, were grown at three different pCO2 (35, 70 and 120 Pa) in three matched, temperature-controlled glasshouse compartments. The difference between leaf and air temperature (ΔT) was monitored diurnally with thermocouples. ΔT increased with both step-increases of ambient pCO2. Average noon leaf temperature increased by 0.4 and 0.3°C for A. lappacea with the 35–70 and 70–120 Pa steps of pCO2 elevation, respectively. For B. bladhii, the increases were 0.5°C for both pCO2 steps. ΔT was strongly dependent on irradiance, pCO2 and air humidity. Leaf gas exchange was measured at constant temperature and high irradiance at the three growth pCO2. Under these conditions, CO2 assimilation saturated at 70 Pa, while stomatal conductance decreased by the same extent (0.58-fold) with both step-increases in pCO2, suggesting that whole-plant water use efficiency of C4 grasses would increase beyond a doubling of ambient pCO2. The ratio of intercellular to ambient pCO2 was not affected by short- or long-term doubling or near-tripling of pCO2, in either C4 species when measured under standard conditions.


2001 ◽  
Vol 150 (2) ◽  
pp. 405-418 ◽  
Author(s):  
Tali D. Lee ◽  
Mark G. Tjoelker ◽  
David S. Ellsworth ◽  
Peter B. Reich

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Mohd Hafiz Ibrahim ◽  
Hawa Z. E. Jaafar ◽  
Ehsan Karimi ◽  
Ali Ghasemzadeh

A split plot 3 by 4 experiment was designed to investigate and distinguish the relationships among production of secondary metabolites, soluble sugar, phenylalanine ammonia lyase (PAL; EC 4.3.1.5) activity, leaf gas exchange, chlorophyll content, antioxidant activity (DPPH), and lipid peroxidation under three levels of CO2(400, 800, and 1200 μmol/mol) and four levels of light intensity (225, 500, 625, and 900 μmol/m2/s) over 15 weeks inLabisia pumila. The production of plant secondary metabolites, sugar, chlorophyll content, antioxidant activity, and malondialdehyde content was influenced by the interactions between CO2and irradiance. The highest accumulation of secondary metabolites, sugar, maliondialdehyde, and DPPH activity was observed under CO2at 1200 μmol/mol + light intensity at 225 μmol/m2/s. Meanwhile, at 400 μmol/mol CO2 + 900 μmol/m2/s light intensity the production of chlorophyll and maliondialdehyde content was the highest. As CO2levels increased from 400 to 1200 μmol/mol the photosynthesis, stomatal conductance,fv/fm(maximum efficiency of photosystem II), and PAL activity were enhanced. The production of secondary metabolites displayed a significant negative relationship with maliondialdehyde indicating lowered oxidative stress under high CO2and low irradiance improved the production of plant secondary metabolites that simultaneously enhanced the antioxidant activity (DPPH), thus improving the medicinal value ofLabisia pumilaunder this condition.


Horticulturae ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 73
Author(s):  
Zulias Mardinata ◽  
Tengku Edy Sabli ◽  
Saripah Ulpah

The identification of the key components in the response to drought stress is fundamental to upgrading drought tolerance of plants. In this study, biochemical responses and leaf gas exchange characteristics of fig (Ficus carica L.) to water stress, short-term elevated CO2 levels and brassinolide application were evaluated. The ‘Improved Brown Turkey’ cultivar of fig was propagated from mature two- to three-year-old plants using cuttings, and transferred into a substrate containing 3:2:1 mixed soil (top soil: organic matters: sand). The experiment was arranged as a nested design with eight replications. To assess changes in leaf gas exchange and biochemical responses, these plants were subjected to two levels of water stress (well-watered and drought-stressed) and grown under ambient CO2 and 800 ppm CO2. Water deficits led to effects on photosynthetic rate, stomatal conductance, transpiration rate, vapour pressure deficit, water use efficiency (WUE), intercellular CO2, and intrinsic WUE, though often with effects only at ambient or elevated CO2. Some changes in content of chlorophyll, proline, starch, protein, malondialdehyde, soluble sugars, and activities of peroxidase and catalase were also noted but were dependent on CO2 level. Overall, fewer differences between well-watered and drought-stressed plants were evident at elevated CO2 than at ambient CO2. Under drought stress, elevated CO2 may have boosted physiological and metabolic activities through improved protein synthesis enabling maintenance of tissue water potential and activities of antioxidant enzymes, which reduced lipid peroxidation.


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