Heavy Metal Pollution and Medicinal Plants
Azamal Husen in Environmental Pollution and Medicinal Plants, 2022
HMs absorption in medicinal plants can interact with the accumulation of NPK in the plant body and may result in the deficiency of certain macronutrients. In another experiment conducted by Mishra et al. (2014) it was found that supplementing Cd to the medicinal plant (Withania somnifera) resulted in NPK deficiency along with interruption in growth and development, and necrosis, as well as necrotizing at higher concentrations of Cd. Moreover, photosynthetic pigments’ concentration improved compared to the control (1.75-fold higher than control) at 50 μM and decreased by 0.13-fold at 300 μM. In comparison to the control, total chlorophyll contents (chl a + chl b), chl a and b, and carotenoids declined by 0.1- to 0.2-fold under higher concentrations of Cd, i.e. 200 to 300 μM.
Physical Factors
Michael J. Kennish in Ecology of Estuaries Physical and Chemical Aspects, 2019
Light intensity, quality, and duration (photoperiod) affect the activities and processes of estuarine organisms. Autotrophic production is a function of light intensity. Photosynthesis increases logarithmically with increasing light intensity up to a level of light saturation (Figure 12). At very high light intensities, photosynthesis becomes inhibited because of the bleaching of photosynthetic pigments (e.g., chlorophyll a) or the arresting of pigment production in autotrophs.9 Over extended periods, high light intensities can be lethal to phytoplankton,82 and at low light intensities, photosynthesis declines until the compensation light intensity is reached where photosynthesis just balances respiration. The compensation point occurs at a depth at which light intensity approximates 1% of the surface radiation. The intensity of light at the air-sea surface interface depends on latitude, season, time of day, and weather conditions.
Chemopreventive Agents
David E. Thurston, Ilona Pysz in Chemistry and Pharmacology of Anticancer Drugs, 2021
Although first isolated in an impure form in 1910, the structure of lycopene was not elucidated until approximately 1930. However, due to the complexity of the molecule, particularly in terms of the number of double bonds and their relative configurations, it was not synthesized until 1950. In photosynthetic organisms, including plants, algae, fungi, and photosynthetic bacteria, lycopene is a key intermediate in the biosynthesis of a number of carotenoids, including β-carotene and also the xanthophylls, which play an important role in the red, yellow, or orange photosynthetic pigment-protein complexes, and the processes of photosynthesis and the protection of photosynthetic organisms from excessive light damage. Owing to its strong color, lycopene is used as a food coloring agent known as E160d.
Phytochemical composition, cytotoxicity, antioxidant and antimicrobial responses of Lavandula dentata L. grown under different levels of heavy metals stress condition
Published in Drug and Chemical Toxicology, 2023
Souhila Terfi, Zineb Djerrad, Soumeya Krimat, Fatma Sadi
Photosynthetic pigments (chlorophyll a, b and carotenoid) were determined according to Arnon (1949), with slight modifications. Leaf samples (0.5 g) were homogenized with 8 mL of acetone (80%), filtered and made up to a final volume of 50 mL. The absorbance was measured at 663, 646 and 470 nm using UV spectrophotometer. The photosynthetic pigments contents were calculated using the followed equations (Doğanlar and Atmaca 2011):Chlorophyll a (Chl a): (12.21× A663 – 2.81 × A646) × 50/500 mg of leaf weight,Chlorophyll b (Chl b): (20.13 × A646 – 5.03 × A663) × 50/500 mg of leaf weight,Total chlorophyll (Total Chl): (7.18 × A663 + 17.32 × A646) × 50/500 mg of leaf weight,Carotenoid (Car): [(1000 × A470 − 3.27 × Chl a − 104 × Chl b)/229] × 50/500 mg of leaf weight.
Mechanism of long-term toxicity of CuO NPs to microalgae
Published in Nanotoxicology, 2018
Xingkai Che, Ruirui Ding, Yuting Li, Zishan Zhang, Huiyuan Gao, Wei Wang
We think that destruction of chloroplast structure by CuO NPs was related to Cu ions released by CuO NPs and Cu2O NPs. On the one hand, a large number of Cu ions released by CuO NPs were absorbed by microalgae (Figure 2(A,B) and Supporting Information Figure S3A) to result in Cu ions toxicity for chloroplast (Figures 4 and 8). On the other hand, however, we find that microalgae could not only absorb Cu ions released by CuO NPs but also could directly enrich CuO NPs which were converted into Cu2O NPs (2–5nm) in the cell concentrated in chloroplast (Figure 6; Supporting Information Figure S6). When microalgae was treated with Cu2+ ions that released the same content of Cu ions as the CuO NPs do into the supernatant, we observed that damage degree of chloroplast caused by Cu2+ was weaker than that caused by CuO NPs (Figures 4 and 8). These results indicate that damage of chloroplast by CuO NPs was not only related to Cu ions toxicity but also might be related to direct damage of chloroplast by CuO NPs and Cu2O NPs. These injuries resulted in chloroplast deformation (Figure 6(B,G)) and degradation of chlorophyll (Figure 7). Further, destruction of chloroplast structure and degradation of photosynthetic pigments disturbed the light conversion and light use efficiency (Figures 8(A,B) and 9(G,H)).
Early flowering, good grain quality mutants through gamma rays and EMS for enhancing per day productivity in rice (Oryza sativa L.)
Published in International Journal of Radiation Biology, 2021
Vinithashri Gautam, Manonmani Swaminathan, Manoharan Akilan, Anand Gurusamy, Meena Suresh, Bhuvaneswari Kaithamalai, A. John Joel
The frequency of induced chlorophyll mutations in M2 generation is considered as a reliable index for determining the mutagen potential as chlorophyll mutants provides great accuracy in their scoring (Gustafson 1940; Mackey 2010). Apart from the evaluation of effectiveness and efficiency, chlorophyll mutations also play the role in predicting the size of vital factor mutations. The development of chlorophyll pigment is influenced by many genes localized on several chromosomes which could be adjacent to the centromere and proximal segments of chromosomes (Swaminathan 1964, 1965; Goud 1967). Changes occurring in genes responsible for the synthesis of photosynthetic pigments leads to chlorophyll deficiencies. These chlorophyll mutations give a clear picture of the evaluation of the genetic effects of mutagenic treatments. Hence, these chlorophyll mutants are utilized as markers in genetics, physiological, and biochemical investigations.
Related Knowledge Centers
- Bacteria
- Biological Pigment
- Chlorophyll A
- Chloroplast
- Cyanobacteria
- Photosynthesis
- Xanthophyll
- Carotene
- Pheophytin
- Chlorophyll B