halimeh hassanpour

In the current study, the effect of different silicon dioxide nanoparticles (SiO2 NPs) concentrations was investigated on biomass yield, chlorophyll (Chl a) pigment, antioxidant enzymes, and defence metabolites of Spirulina platensis alga. The alga sample was cultured in the Zarrouk medium supplemented with various SiO2 NPS concentrations (0, 50, 100, and 150 mg L-1) for two weeks. Results showed that SiO2 NPs at 100 mg L-1 increased significantly dry weight, specific growth rate, and Chl pigment, possibly due to the induction of protein content and antioxidant enzyme activities of catalase and peroxidase. Secondary metabolites such as phycobiliprotein, phycocyanin, allophycocyanin, phycoerythrin, carotenoids, and extracellular polymeric substances increased upon all concentrations of SiO2 NP, although their contents were more increased under 100 mg L-1 treatment. Treatment of SiO2 NP at 150 mg L-1 induced toxicity in the algal growth along with the accumulation of H2O2, inhibition of antioxidant enzyme activities, and decline in the content of secondary metabolites. The findings suggest that 100 mg L-1 SiO2NPs is an optimum concentration for sustainable production of S. platensis, and may act as an elicitor to stimulate antioxidant metabolites for suppressing oxidative injuries.

Light is as an environmental factor affecting plant growth. So far, various light sources have been used to grow plants in closed systems and space studies. Traditional light sources have some problems and are not suitable for space research. The biggest problem of them is the need for the high energy source, power supply weight, and heat production. LED light spectra were designed to solve plant cultivation problems in space for the first time and are recently used in terrestrial research such as greenhouses and plant cultivation rooms. The LED spectra have different colors, but laboratory studies are needed to determine the plants' involvement for these spectra. In this study, LED light technology, effect of spectra on the growth, production of metabolites and optical receptors are investigated.

 Microgravity is one of the environmental stresses in space that affects on the structure of cellular organelles and metabolites in plant. In the present research, the effect of microgravity in times 3, 7 and 10 days on root and hypocotyl growth rate, fresh and dry weight, cell and organelles ultrastructure with Transmission Electron microscope (TEM) and some antioxidative capacity ( phenol, flavonoid and inhibition of DPPH radicals) were investigated in henbane (Hyoscyamus niger L.) seedling. The results showed that microgravity led to increase root and hypocotyle length as compared to control. Amydons were spread throughout the cell in microgravity treatment, while in control samples, they were deposited on the cell wall in the direction of gravity. Mitochondria were variable in shape and number. The endoplasmic reticulum in 10-day treatment was more voluminous and longer than the control. Also, the vacuole was observed more voluminous as compared to control. Total phenol, flavonoid, and inhibition of DPPH radicals increased significantly(P < 0.05). It seems, cellular changes and secondary metabolism induced under microgravity are related to oxidative stress.

Light is a vital factor for plant cultivation. LED lamps in different spectra have some advantages such as low heat production and energy requirement, and long lifespan, which was used for the first time to design plant growth chambers in closed culture systems and space research. In this research, impact of light spectrums was studied on the growth mechanisms through chlorophyll pigments, enzyme defense system, and antioxidant metabolite analyses. Seeds were cultivated in Murashige and Skoog medium and exposed to different light spectrums of white, red, blue, and red-blue. Then, the seedlings were harvested for growth and biochemical analyses after 4 weeks. Results showed that red-blue and blue lights induced the fresh weight, dry weight, root length, adventitious roots, chlorophyll content, protein, flavonoids and antioxidant enzymes of superoxide dismutase and catalase. Blue spectrum significantly decreased stem length and increased the relative water content. Moreover, the highest amount of hydrogen peroxide was observed in seedlings treated with red light. It seems that light spectra by changing the hydrogen peroxide level can regulate antioxidant enzyme activity and enhance antioxidant metabolites, and red-blue light may use as a suitable lighting spectrum for the design of M. chamomilla cultivation chamber in space research.

Climate alteration and population growth have been responsible for the yield decline in crop. Until now, several researchers have been used various physical and chemical factors to stimulate plant growth and development. Static magnetic field (SMF) application has been identified to be a physical technique and useful to control plant diseases and stimulation of biomass yield. Little studies have been made to detection the role of SMF on plant physiological response, defense mechanisms, and plant tolerance against various stress conditions. On the other hand, application of man-made devices producing magnetic field (MF) is also increasing, and more studies are needed on living organisms. This review investigates the impact of MF on induction of seed germination and plant growth. Also, the supportive impact of SMF was investigated on membrane permeability, ion currents, secondary metabolite and antioxidant enzyme activities to suppress oxidative damage. The potential impact of SMF on enzymatic and non-enzymatic antioxidants can cause to increase plant tolerance during adverse conditions of other stresses such as salinity, metal contamination, drought ant etc. This review presents the basic and recent studies about the effect of SMF on plant adaptation to stress environment and emphasizes more research is involved to illuminate how SMF is precepted by cells, and the molecular mechanisms of SMF for plant protection under other stress conditions.

The selection of suitable biological sample for space studies has vital importance. Plant cell suspension culture containing a homogenous population of proliferating cells prepares the proper situation to study various cell responses under stress conditions, especially microgravity. Cell culture systems in the laboratory can be performed in the two-dimensional (2D) and 3D culture models. In the 2D culture model, cells are cultured as a monolayer and show different growth and differentiation responses compared to normal conditions. While in the 2D model, cells are cultured in conditions that are similar to the normal conditions of cells and tissues in the living organisms and are used for medicinal purposes, production of secondary metabolites and biomass on a large scale. In this research, recent advancements and technologies used for 3D cell culture will be studied.

 This study aimed to investigate the effect of microgravity and light spectral composition on the levels of antioxidant enzyme activity, minerals, and  some photosynthetic pigments in Physalis alkekengi.

This study was performed in vitro. Seedlings were exposed to the microgravity treatments under two different light conditions, including white (C) and red+blue (R+B).

 The microgravity treatments were more capable of rapidly influencing growth performance than the light spectrum quality. Red+blue light increased the amount of chlorophyll a and b. Antioxidant enzymes under microgravity stress showed an increase, while changing the quality of the light spectrum did not make a significant difference. An increase in malondialdehyde (MDA) was observed in the microgravity treatment compared to the light spectrum. The amount of Cu+2 and Zn+2 were increased by the R+B+microgravity treatment. However, Mn+2 was increased in the microgravity treatment. The highest uptake of Fe+2 and Ca+2 was recorded under microgravity conditions. R+B+Microgravity treatment increased K+ content compared to white control. The microgravity treatment increased Mg+2 in the root cell.

 In general, microgravity and light spectrum can increase biomass. Microgravity has little effect on photosynthetic pigments, but the R+B light spectrum increased the pigments. Microgravity increased the activity of antioxidant enzymes and the content of MDA. The concentration of some elements in roots and leaves can be modified by the light and microgravity conditions.

This study was performed to evaluate some growth indices, antioxidant activity, total flavonoids, accumulation of soluble sugars and changes in total protein under microgravity conditions and light spectrum composition with four replications on P. alkekengi. Seedlings grown in vitro were exposed to the microgravity treatments under two different light conditions, including white (C) and red+blue (R+B). The results of this study showed that the treatment of R+B light spectrum increased seed germination and leaf relative water content (RWC) by 23.9% and 32.1% respectively, compared to control. Microgravity treatment under white light (Microgravity) and microgravity treatment under red+blue light (R+B+Microgravity) biomass increased 78.1% and 97.4% respectively, compared to the white control. The level of antioxidant activity in the treatment groups showed a significant increase in the leaves, which was the highest value under microgravity under R+B light (10.1%). R+B+Microgravity treatment significantly improved the total flavonoid content by about 19.6% compared to the control. The highest activity of phenylalanine ammonialyase (PAL) enzyme was measured at 9.7% in the root under microgravity conditions. R+B light and microgravity treatment increased the amount of total protein and soluble sugar and also the simultaneous use of these two treatment showed the highest amount (71.8% and 45.1% respectively). The R+B light spectrum can be used improve seed germination and the RWC. In general, R+B+Microgravity treatment synergistically increases biomass, antioxidant activity, total protein and soluble sugars compared to white control.

Microgravity and cosmic radiation are the space environmental stresses which can cause DNA damage in living organisms. Radiations injuries the cell DNA directly through the interaction of charged particles with DNA molecules or indirectly by the production of free radicals. In addition, radiation can alter cell wall composition, activate free radical scavenging enzymes, and accumulate antioxidant compounds. Although plants have evolved some mechanisms to deal with the damages, space conditions, especially microgravity can play a role in repairing DNA damage. More DNA damages can induce double strand breaks of DNA, chromosome abnormality, micro-nuclei formation, and increase the risk of cell death. In this study, the effect of space environmental stresses on DNA damage and response mechanisms will be investigated in space flight or simulated conditions.

This study was conducted in order to determine the effects of different concentrations of synthesized Fe3O4 nanoparticles (NPs) on the growth, the content of secondary metabolites and antioxidant capacity in Matricaria chamomilla. With this aim, four levels of Fe3O4 NPs concentrations were applied as follows: basic Murashing and Skoog solution (control), 25, 50 and 100 mg L-1 Fe3O4 NPs. The results indicated that the biomass was higher in the plants that were treated with 25 mg L-1 Fe3O4 NPs than the control plants. Biomass was declined in 50 and 100 mg L-1 Fe3O4-exposed plants compared with the unexposed plants. Relative water content was gradually decreased with the enhancement of Fe3O4 concentration. Fe3O4 NPs in 50 and 100 mg L-1 caused a significant induction in number of root. Fe3O4 NPs treatment enhanced production of secondary metabolites such as total phenol and total flavonoid in roots and leaves of M. chamomilla. Moreover, Fe3O4 NPs increased antioxidant ability of the roots and leaves by inducing DPPH scavenging activity at 25 mg L-1 Fe3O4. The results might identify that the application of Fe3O4 NPs can be a useful war for increasing higher content of secondary metabolites in the M. chamomilla plants.

In this study the effect of C. colocynthis extract and phycocyanin on the growth of colon cancer cells, and the expression of Caspase 3 and Bax were investigated.Materials &

colon cancer cells (HT29) were treated with different concentrations of C. colocynthis and phycocyanin extracts for 24, 48 & 72 hours. The percentage of cell survival was then measured by MTT assay. Expression of Caspase 3 and Bax genes was investigated by real-time PCR. At the end results were analyzed by SPSS software.

Significant differences were observed in the average percentage of dead cells with 2 to 30 g/μL concentration of extract, phycocyanin, extract + phycocyanin after 24, 48 and 72 hours (p<0.05). The combination of extract and phycocyanin as well as phycocyanin alone showed stronger inhibitory effects on growth of cancer cells compared to extract (p <0.05). The expression of Bax gene was significantly increased by treatment of combination of extract and phycocyanin (2.55-fold) and also C. colocynthis extract alone (1.67-fold) (p <0.01). In addition, the combination of extract and phycocyanin and Abujahl watermelon extract significantly increased the expression of caspase 3 gene (2.15 and 1.75), respectively (p <0.01).

The anticancer effect of Citrullus Colocynthis extract, as well as phycocyanin can be applied by increase the expression of Bax and caspase 3 genes and as a result, apoptosis induction in cancer cells.

Colorectal cancer has been one of the most common cancers over the past few decades and is expected to increase in the future. Since cancer prevention has been proposed as a promising research strategy, we have investigated the effect of Citrullus colocynthis watermelon extract and phycocyanin compound on the growth of colon cancer cells. subsequently evaluated the expression of apoptosis biomarkers including Caspase-3 and Bax proteins

Human colon cancer cells (HT-29) with different concentrations of Citrullus colocynthis extract and phycocyanin were cultured. The percentage of live cells and expression of Caspase-3 and Bax genes were evaluated by MTT and RT-PCR methods. Then, results were analyzed with SPSS software

There was a significant difference in the average percentage of dead cells in volumes 2 to 30 μL from extract, phycocyanin, extract+phycocyanin after 24, 48, and 72 hours (P> 0.05). However, phycocyanin, extract+phycocyanin were more effective in the inhibition of cancer cells (P<0.05). Moreover, the combination of extract+phycocianine and also extract significantly increased Bax gene expression (2.35, 1.67 times, respectively) (P<0.01). The combination of extract+phycocyanin and Citrullus colocynthis extract significantly increased the expression of caspase-3 gene expression in the cancer cells by a factor of 2.15 and 1.75 (P <0.01).

Extract of Citrullus colocynthis, as well as the combination of extract+phycocyanin by increasing the expression of Bax and caspase-3 genes, induce apoptosis in cancerous cells.

Living organisms have evolved in the presence of constant gravity (1g) on Earth and their growth is related to rate of ribosome, protein biosynthesis, and regulation of cell cycle phases. Microgravity does not have the same effects on different phases of cell cycle such that activity of some phases is increased. It changes the number of cell cycles per time. In the cell growth process, rate of ribosome biosynthesis is decreased under simulated microgravity and a large variation is observed in abundance of nucleolar proteins (Nucleolin and Fibrillarin). Under normal conditions, growth and cell division are coupled, and microgravity uncouples these processes. The study of plant cellular response can help improvement of biological knowledge and preparation of life support systems in space.

LED light spectrums are the proper light source for plant research in the International Space Station and the life support system. In the present study, effects of different light spectrums on some growth parameters, and antioxidant activity were investigated in Anthemis gilanica. Seedlings irrigated with 1/2 Hougland solution under different light spectrums including white, red-blue and deep red. Seedlings were harvested for physiological and biochemical analyzes after 4 weeks. Results showed the fresh and dry weight, relative water content and root length increased under the red-blue light spectrum comparing to other spectrums. Hydrogen peroxide level didn't significantly change under different light spectrums. Seedlings treated with white spectrum showed the highest DPPH scavenging activity. Also, seedlings treated with deep red spectrum showed the maximum shoot length. It seems that decrease of growth under white spectrum is related to transfer carbon and energy sources for antioxidant compound biosynthesis.

Salinity is one of the most important abiotic stresses that have restricted affects on plant growth and yield. Magnetic field can ameliorate the negative effect of salinity with induction of plant antioxidant activity. In present research, the effect of static magnetic fields (0 anf 4 mT) on some physiological parameters and antioxidative capacity were investigated under salinity stress at concentrations of 0, 50 and 100 mM NaCl in Silibum marianum L. The results showed that salinity at 100 mM and no a magnetic field pretreatment led to reduction in fresh (65%) and dry weight (27.7%), relative water content (15.35%), leaf area (29.82%), root length (8.30%) as comparied to control. The lowest IC50 (22.32%) was observed at 50 mM salinity and a magnetic -field strength of 4 milli- tesla . Proline, MDA, hydrogen peroxide, total phenol and flavonoid contents were also significantly increased under 100 mM NaCl treatments. The magnetic field reduced the negative effects of salinity on growth indicators of S. marianum seedlings by increasing the antioxidant capacity, proline, the total phenolic and  flavonoid contents. 4 mT magnetic field also led to a 28.3 and 35.4% reduction of hydrogen peroxide and MDA levels under 100 mM NaCl concentrations. It seems that magnetic field pre-treatment can be reduced the adverse effects of salt on this plant species by increasing antioxidant capacity especially at 50 mM.

Plant study in space under microgravity condition is a very important goal in sending alive animals and human beings to space. Gravity modulates plant growth and its development and these processes are influenced by the balance between cell proliferation and differentiation in meristems. Regulation of cell cycle progression causes cell proliferation and growth and finally produces optimum biomass. Microgravity affects cellular processes and compounds. Plant growth and development changes under such condition, leading to alterations in the cytoplasmic membrane, transcriptome, proteome, cell wall, and Ca2+-signaling in specialized  and not specialized cells of gravity perception. Cellular and molecular studies can help to visualize response mechanisms to microgravity and the  solution of problems in plant culture in space.

In this research, effects of SiO2 nanoparticles (NPs) on the growth, antioxidant properties, and phenolic and flavonoid contents were investigated in Anthemis gilanica plants from the Asteraceae family. Following seed germination, seedlings were cultured under Hoagland growth media and were treated with different concentrations of SiO2NPs (0, 2, 4, 6 and 8 g L-1). The results showed that SiO2 NPs significantly enhanced relative water content (RWC), dry and fresh weights, and shoot length especially at 4 g L-1, but decreased root length with increasing concentrations of NPs. Xylem number and size, and stele diameter increased up to 6 g L-1, and then decreased at higher concentration. Total phenol and flavonoid contents increased under different concentrations of SiO2 NPs, and the maximum content was observed at 6 g L-1. Moreover, SiO2 NPs increased antioxidant activity of extracts by reducing IC50 content especially at 6 g L-1. In conclusion, this study proposes that SiO2 NPs can improve growth and bioactive compounds in A. gilanica by induction of anatomical alterations.

In this study, the effects of different concentrations of silica nanoparticles (NPs) were studied on growth, membrane stability, and antioxidant properties of Matricaria chamomilla in vitro. The sterilized seeds were incubated in different concentrations of silica NPs (0, 2, 4, 6 g L-1) for one hour and then were cultured on Murashing and Skoog medium. Silica NPs application enhanced relative water content and fresh and dry weight of leaf and root. The highest growth was observed at 4 g L-1 silica NPs. Hydrogen peroxide and malondialdehyde significantly reduced at 4 g L-1 silica NPs. Total phenol and flavonoid contents increased by silica NPs treatment, and induction effect of silica NPs was more prominent at 6 g L-1 silica NPs. Low level of IC50 was detected at 6 g L-1 silica NPs. Overall, application of silica NPs at proper concentration can improve growth and induces the production of metabolites in M. chamomilla.

Mechanical vibration is one of abiotic stresses which could affect on growth and development of plant cells. In this research, effect of sinusoidal vibration were studied on some physiological parameters, protein, total phenols and free radical scavenging activity using 2,2-diphenyl-1-picrylhydrazyl (DPPH) in Anthemis gilanica seedlings. Sinusoidal vibrations were applied at 0, 10, 15, 50 and 100 Hz on 10 days seedlings, and were analyzed for physiological and biochemical responses after 30 days. Results showed different responses of growth, antioxidant activity and phenolic content under different frequencies of vibration. Sinusoidal vibrations at frequencies of 15 and 50 Hz resulted in a significant increase in growth parameters, relative water content, chlorophyll a and chlorophyll b and protein content compared to control. Malondialdehyde (MDA) and H2O2 levels decreased significantly at frequencies higher than 10 Hz, and 15 Hz treatment resulted in a 54.55% and 24.5% reduction of hydrogen peroxide and malondialdehyde content as compared to control. Sinusoidal vibrations also increased in free radical scavenging activity by reducing the IC50 value, and the highest decrease was observed at 50 Hz frequency. It seems that increase of antioxidant capacity under proper frequency of vibration can induce A. gilanica growth.

The lighting system is one of the most important components of greenhouse or plant growth chambers in Advanced Life-support System (ALSS). Several designs of such lighting systems have been proposed including the use of natural sunlight and electric supplemental lighting. Due to the limitations of plant growth under natural sunlight on the surface of the moon or Mars, it is essential to use electric lighting although it is high-energy consuming. The characteristics of different electric light types are important in space applications. Different lighting systems are recomended for Earth-based advanced life-support (ALS) system based on electric lighting that have advantages and disadvantages. The results state that LEDs are appropriate for life support system design due to low- energy consumption, lack of heat production, and induction of crop production. In this paper, effect of different light is investigated for usage in the life support system.

Silybum marianum is an important medicinal plant with high antioxidant properties. Static magnetic field (SMF) is a kind of abiotic stresses which can affect growth and antioxidant capacity of medicinal plants. In this research, the effects of SMF on total phenolic and flavonoid contents, radical scavenging activity, and anatomical alterations were investigated in S. marianum seedlings. Five-day-old seedlings were treated with different intensities of SMF (0, 2, 4 and 6 mT) for one hour, and then were irrigated with 1/2 Hoagland solution for four weeks. Results showed that SMF up to 4 mT increased significantly fresh weight, dry weight, leaf area, relative water content (RWC), root length and then decreased these parameters at 6 mT. At 4 mT, SMF caused an 125, 132.73 and 52.19% increase of dry weight, leaf area and root length as compared to control, respectively. Metaxylem number and size, aerenchyma formation and stele diameter improved under SMF. Lipid peroxidation (MDA) decreased especially at 4 mT, although H2O2 level increased in S. marianum shoots. SMF also induced total phenolic (93.89%) and flavonoid contents (36.43%), and decreased IC50 values (43.01%) especially at 4 mT in leaves. It suggests that SMF at proper frequency could improve antioxidant capacity of plant cells by regulation of H2O2 level and membrane stability.

The cultivation of higher plants plays an essential role in bio-regenerative life support systems for food production, CO2reduction, O2 production, as well as for waste recycling and water management. Fresh crops are also expected to have a positive impact on the crew psychological health. Space has unique conditions for biological studies.Biological samples in the space are subject to various stresses including zero gravity, microgravity, irradiation, vibrations, magnetic fields and microorganisms. The effect of space stresses that living organisms are important for human long-duration missions to space and for the improvement of science and technology. Sending plant biological samples to the space needs the design and construction of plant growth systems. At first, these systems had a simple structure, and then they becamemore advanced during the flight. The study of these systems is important in terms of theirappearance, lighting system, food circulation, ventilation system and temperature. In this paper, plant cultivation systems are studied in Salyut Space Station,Mir, Space Shuttle and International Space Station.

Water deficit is one of the most important environmental stresses limiting plant growth and productivity around the world including Iran. Plants adapted to environmental stress with several strategies such as changes in antioxidant enzyme metabolism. Pennyroyal (Mentha pulegium L.) is an aromatic and medicinal plant of the Labiatae family that is widely used in traditional medicine. In this research, the effects of water deficit stress on growth, photosynthesis and antioxidant enzyme activities in leaf and root organs of M. pulegium plants were studied. Complete randomized block design have been used with four replications. Water deficit was studied at four field capacity levels (100, 75, 50 and 25%). Results showed that the growth, productivity and photosynthesis parameters significantly decreased under water deficit stress. Water deficit significantly increased the activity of antioxidant enzyme such as superoxide dismutase, peroxidase and ascorbate peroxidase in both organs, but the level of increase was more in roots than leaves of plant. Unlike to other enzymes, catalase activity decreased with the increase of water deficit levels, and highest activity was observed in leaves. It seems that pennyroyal plants can tolerate water deficit stress by dedicating less carbon source for growth, increase of antioxidant enzyme activity and regulation of antioxidant enzyme distribution in different organs.