ASSESSMENT OF CYTOTOXICITY AND GENOTOXICTY OF TREATED WASTEWATER BY ALLIUM CEPA BASED BIOASSAY: A CASE STUDY IN TABUK, KSA

Water is an elixir for life, yet we are not able to replenish it to nature at the same pace with which we are extracting it. Tabuk, the capital city of the north-west region of KSA produce 110,000 m3/day of wastewater. This wastewater is treated on the outskirts of the city. KSA is considering wastewater as a major water source and aims to achieve its 100% usage by 2025. In Tabuk, most of the treated wastewater is used for groundwater recharge; our aim was to evaluate the water quality by Allium cepa bioassay. This is the first report from the KSA and gives an insight into the cyto-genotoxicity of treated wastewater in the arid environment. In this current study released treated wastewater from Tabuk, wastewater treatment plant was collected from different locations and its physicochemical properties were examined, tap water and distilled water was used as the control. In addition, assessment of cyto-genotoxicity of the said treated wastewater was done by A.cepa bioassay. The water quality parameters such as pH, temperature, conductivity, TDS and Turbidity values shows an increasing trend as we move from S1 to S4. Salinity values were constant and dissolved oxygen value was highest at S1 as compared to all other sites. The heavy metal values of Cr, Mn, Cu, Zn, Cd, and Pb were decreased from S1 to S4. In A. cepa test, macroscopic parameters, root number, and root length were increased from S1 to S4. The microscopic parameter like mitotic index was significantly inhibited at S1 as compare to other sites. Abnormal cell shape, spindle disorientation, chromosomal adherence, fragmentation, chromosomal bridges, and micronuclei were recorded after 5 days. The values concluded that water at S1 and S2 was more harmful compared to S3 and S4. The elemental analysis at S4 and the values of root number, root length, fewer abnormalities in the cell shows possible phytoremediation effect of Phragmitis sp. Key words: Cytotoxicity, Genotoxicity, Chromosomal bridges, Phytoremidiation, Aquifer recharge

Ecological variations and role of heat shock protein in Artemisia judaica L. in response to temperature regimes of Tabuk, Saudi Arabia

Artemisia judaica L. (Compositae) are shrubby herbs growing wildly in Tabuk region and distributed in the desert regions. This region is characterized by extremely variable environmental conditions where the temperature varies from extreme low to extreme high. These temperature regimes have a profound effect on morphology, growth physiology and biochemistry of the plants. The plant samples were collected from Tabuk–Jordan road (760 m above sea level) in the month of January, April, July and October 2013 to evaluate the effect of temperature dynamics on A. judaica L. in four different seasons. Physiological, biochemical alterations and heat shock proteins (HSPs) were studied during these seasons in order to evaluate the environmental adaptation and stress tolerance in response to temperature variations. Plant growth parameters showed a significant increase in height, fresh and dry matter accumulation, total chlorophyll, nitrogen, phosphorus, potassium, artemisinin and leaf relative water contents investigated in the month of April and October. Growth of plant was suppressed and an active role of carbonic anhydrase (CA), catalase (CAT), peroxidase (POD) and superoxide dismutase (SOD) was observed to cope with the extreme low temperature in January and extreme high temperature in July 2013. However, the plants collected in October and April did not show a statistical difference. Inductions in the expression of HSP90 were recorded in all the plants collected during April and October 2013 with no statistically significant difference. Therefore, based on the results it is recommended that during April and October the environmental conditions are best suitable for growth, development and medicinal use of Artemisia. Keywords: Antioxidants, Climate change, Growth, Heat shock proteins, Medicinal plant

Ethylene mediated physiological response for in vitro development of salinity tolerant tomato

Tomato is an important crop and has immense health benefits and medicinal value. Here, we described how salinity stress affects tomato plant growth and developmental processes and productivity. It causes ionic toxicity, oxidative damage, osmotic stress, and hormonal imbalance. In this review, we emphasized the crucial role of ethylene (ET) towards in vitro development of tomato crop by mediating stress response, particularly high salt. There are evidences that salinity stress modulates the expression of ACS and beta-CAS, which leads to ET and cyanide accumulation. We draw attention to how ET negatively or positively mediates salinity stress response by maintaining endogenous biomolecules, Na+/K+ ion balance and redox homeostasis. How ET inhibitors and polyamines as protectants reverse the negative effects of ET/salinity stress-induced cellular damage by cross talk with important physiological processes-photosynthesis and respiratory and salt overly sensitive (SOS). The literature appraised herein will contribute to a better understanding of the development of salinity stress tolerant tomato

Developmental stages-specific response of anise plants to laser-induced growth, nutrients accumulation, and essential oil metabolism

Compared to seeds and mature tissues, sprouts are well known for their higher nutritive and biological values. Fruits of Pimpinella anisum (anise) are extensively consumed as food additives; however, the sprouting-induced changes in their nutritious metabolites are hardly studied. Herein, we investigated the bioactive metabolites, phytochemicals, and antioxidant properties of fruits, sprouts (9-day-old), and mature tissue (5-week-old) of anise under laser irradiation treatment (He-Ne laser, 632 nm). Laser treatment increased biomass accumulation of both anise sprouts and mature plants. Bioactive primary (e.g., proteins and sugars) and secondary metabolites (e.g., phenolic compounds), as well as mineral levels, were significantly enhanced by sprouting and/or laser light treatment. Meanwhile, laser light has improved the levels of essential oils and their related precursors (e.g., phenylalanine), as well as enzyme activities [e.g., O–methyltransferase and 3-Deoxy-D-arabino-heptulosonate-7-phosphate synthase (DAHPS)] in mature tissues. Moreover, laser light induced higher levels of antioxidant and anti-lipidemic activities in sprouts as compared to fruits and mature tissues. Particularly at the sprouting stage, anise was more responsive to laser light treatment than mature plants

Influence of Nano-Chitosan Loaded with Potassium on Potassium Fractionation in Sandy Soil and Strawberry Productivity and Quality

Under sandy soil conditions, increasing the efficiency of potassium (K) fertilizers is considered to be a major limiting factor for improving the productivity and quality of fruit crops. In this context, utilizing nanotechnology has emerged as a novel technique to increase the efficiency of K applications. In our study, two field trials were conducted, in two consecutive seasons (2019/2020 and 2020/2021), to compare the effects of nano-chitosan loaded with K as a foliar treatment with those of conventional soil applications of K on plant growth, yield, and quality of strawberry plants grown in sandy soil. Strawberry plants were treated with 12 different treatments, which were replicated three times in a randomized complete block design in each growing season. Potassium sulfate (K2SO4, 48% K2O) was applied to the soil at a rate of 150.0 kg acre−1 (recommended rate, 100%). Meanwhile, the spraying of nano-chitosan loaded with K was applied at 1000 mg L−1 as a control. In addition, K2SO4 was applied either individually or in combination at the rate of 112.5 or 75.0 kg acre−1 with four nano-chitosan-K dosages (250, 500, 750, and 1000 mg L−1). After harvesting, soil samples were collected and prepared to determine K fractions. As well, plant samples were collected to determine the vegetative growth parameters and the foliage content of NPK and chlorophyll. Eventually, the yield traits and quality parameters were evaluated. A principal component analysis was conducted to determine the interrelationships of the treatments’ averages and their effects on yield components and quality traits. A combined analysis was performed for the two studied seasons and the values were the mean of six replications. The results indicated that the application of common K fertilizer (150.0 kg K2SO4 acre−1) resulted in the maximum increase in soluble and exchangeable K in the soil, which was comparable to those observed with 112.5 kg K2SO4 acre−1 + 1000 mg L−1 nano-chitosan-K and 112.5 K2SO4 acre−1 + 750 mg L−1 nano-chitosan-K. The total yield, marketable yield, and fruit firmness were all significantly increased by the latter two treatments compared to the control group. Furthermore, plots treated with 112.5 kg K2SO4 acre−1 + 1000 mg L−1 nano-chitosan-K significantly increased the total soluble solids, vitamin C levels, acidity, total sugar, and anthocyanin levels in strawberry fruits. In conclusion, under sandy soil conditions, the utilization of nanoparticles could be an indispensable tool for manipulating fertilization management when cultivating strawberries. The K status of the soil was improved by applying 75% of the recommended dose of mineral K in combination with 1000 or 750 mg L−1 of nano-chitosan-K, without compromising strawberry yield or quality

Effect of Elevated CO₂ on Biomolecules’ Accumulation in Caraway (<i>Carum carvi</i> L.) Plants at Different Developmental Stages

Caraway plants have been known as a rich source of phytochemicals, such as flavonoids, monoterpenoid glucosides and alkaloids. In this regard, the application of elevated CO2 (eCO2) as a bio-enhancer for increasing plant growth and phytochemical content has been the focus of many studies; however, the interaction between eCO2 and plants at different developmental stages has not been extensively explored. Thus, the present study aimed at investigating the changes in growth, photosynthesis and phytochemicals of caraway plants at two developmental stages (sprouts and mature tissues) under control and increased CO2 conditions (ambient CO2 (a CO2, 400 ± 27 μmol CO2 mol−1 air) and eCO2, 620 ± 42 μmol CO2 mol−1 air ppm). Moreover, we evaluated the impact of eCO2-induced changes in plant metabolites on the antioxidant and antibacterial activities of caraway sprouts and mature plants. CO2 enrichment increased photosynthesis and biomass accumulation of both caraway stages. Regarding their phytochemical contents, caraway plants interacted differently with eCO2, depending on their developmental stages. High levels of CO2 enhanced the production of total nutrients, i.e., carbohydrates, proteins, fats and crude fibers, as well as organic and amino acids, in an equal pattern in both caraway sprouts and mature plants. Interestingly, the eCO2-induced effect on minerals, vitamins and phenolics was more pronounced in caraway sprouts than the mature tissues. Furthermore, the antioxidant and antibacterial activities of caraway plants were enhanced under eCO2 treatment, particularly at the mature stage. Overall, eCO2 provoked changes in the phytochemical contents of caraway plants, particularly at the sprouting stage and, hence, improved their nutritive and health-promoting properties