Antioxidant enzymes as bio-markers for copper tolerance in safflower (Carthamus tinctorius L.)

Activities of antioxidants enzymes were investigated in order to evaluate protective mechanism of plants against oxidative stress induced by high concentration of copper. Safflower (Carthamus tinctorius L.) plants were exposed to 100 μM copper (Cu) for two weeks under controlled environmental conditions using hydroponic culture. Cu induced changes in chlorophyll and carotenoids pigments. More Cu accumulated in the roots as compared with the leaves. Level of lipid peroxidation and antioxidative enzyme activities (peroxidase, catalase and superoxide dismutase) also correlated with the Cu content of the plant tissues. However, restricted transfer of the metal to the foliage and enhanced activity of peroxidase, catalase and superoxide dismutase may be of great significance for scavenging oxidative stress caused by excessive copper in safflower plants. Thus, these antioxidant enzymes served as good predictors for the evaluation of heavy metal tolerance.Keywords: Carthamus tinctorius, copper stress, oxidative damage, antioxidant defenseAfrican Journal of Biotechnology Vol. 9(33), pp. 5441-5444, 16 August, 201

Plants in vitro propagation with its applications in food, pharmaceuticals and cosmetic industries; current scenario and future approaches

Plant tissue culture technique employed for the identification and isolation of bioactive phytocompounds has numerous industrial applications. It provides potential benefits for different industries which include food, pharmaceutical and cosmetics. Various agronomic crops i.e., cereals, fruits, vegetables, ornamental plants and forest trees are currently being used for in vitro propagation. Plant tissue culture coupled with biotechnological approaches leads towards sustainable agricultural development providing solutions to major food security issues. Plants are the rich source of phytochemicals with medicinal properties rendering them useful for the industrial production of pharmaceuticals and nutraceuticals. Furthermore, there are numerous plant compounds with application in the cosmetics industry. In addition to having moisturizing, anti‐ageing, anti‐wrinkle effects; plant-derived compounds also possess pharmacological properties such as antiviral, antimicrobial, antifungal, anticancer, antioxidant, anti-inflammatory, and anti-allergy characteristics. The in vitro propagation of industrially significant flora is gaining attention because of its several advantages over conventional plant propagation methods. One of the major advantages of this technique is the quick availability of food throughout the year, irrespective of the growing season, thus opening new opportunities to the producers and farmers. The sterile or endangered flora can also be conserved by plant micro propagation methods. Hence, plant tissue culture is an extremely efficient and cost-effective technique for biosynthetic studies and bio-production, biotransformation, or bioconversion of plant-derived compounds. However, there are certain limitations of in-vitro plant regeneration system including difficulties with continuous operation, product removal, and aseptic conditions. For sustainable industrial applications of in-vitro regenerated plants on a large scale, these constraints need to be addressed in future studies

Current Progress and Open Challenges for Combined Toxic Effects of Manufactured Nano-Sized Objects (MNO’s) on Soil Biota and Microbial Community

Soil is a porous matrix containing organic matter and minerals as well as living organisms that vary physically, geographically, and temporally. Plants choose a particular microbiome from a pool of soil microorganisms which helps them grow and stay healthy. Many ecosystem functions in agrosystems are provided by soil microbes just like the ecosystem of soil, the completion of cyclic activity of vital nutrients like C, N, S, and P is carried out by soil microorganisms. Soil microorganisms affect carbon nanotubes (CNTs), nanoparticles (NPs), and a nanopesticide; these are called manufactured nano-objects (MNOs), that are added to the environment intentionally or reach the soil in the form of contaminants of nanomaterials. It is critical to assess the influence of MNOs on important plant-microbe symbiosis including mycorrhiza, which are critical for the health, function, and sustainability of both natural and agricultural ecosystems. Toxic compounds are released into rural and urban ecosystems as a result of anthropogenic contamination from industrial processes, agricultural practices, and consumer products. Once discharged, these pollutants travel through the atmosphere and water, settling in matrices like sediments and groundwater, potentially rendering broad areas uninhabitable. With the rapid growth of nanotechnology, the application of manufactured nano-objects in the form of nano-agrochemicals has expanded for their greater potential or their appearance in products of users, raising worries about possible eco-toxicological impacts. MNOs are added throughout the life cycle and are accumulated not only in the soils but also in other components of the environment causing mostly negative impacts on soil biota and processes. MNOs interfere with soil physicochemical qualities as well as microbial metabolic activity in rhizospheric soils. This review examines the harmful effect of MNOs on soil, as well as the pathways used by microbes to deal with MNOs and the fate and behavior of NPs inside the soils

Enhanced Production of Active Photosynthetic and Biochemical Molecules in L. Using Biotic and Abiotic Elicitors in Hydroponic Culture.

Elicitors are stressors that activate secondary pathways that lead to the increased production of bioactive molecules in plants. Different elicitors including the fungus Aspergillus niger (0.2 g/L), methyl jasmonate (MeJA, 100 µM/L), and silver nanoparticles (1 µg/L) were added, individually and in combination, in a hydroponic medium. The application of these elicitors in hydroponic culture significantly increased the concentration of photosynthetic pigments and total phenolic contents. The treatment with MeJA (methyl jasmonate) (100 µM/L) and the co-treatment of MeJA and AgNPs (silver nanoparticles) (100 µM/L + 1 µg/L) exhibited the highest chlorophyll a (29 µg g-1 FW) and chlorophyll b (33.6 µg g-1 FW) contents, respectively. The elicitor MeJA (100 µM/L) gave a substantial rise in chlorophyll a and b and total chlorophyll contents. Likewise, a significant rise in carotenoid contents (9 µg/g FW) was also observed when subjected to meJA (100 µM/L). For the phenolic content, the treatment with meJA (100 µM/L) proved to be very effective. Nevertheless, the highest production (431 µg/g FW) was observed when treated with AgNPs (1 µg/L). The treatments with various elicitors in this study had a significant effect on flavonoid and lignin content. The highest concentration of flavonoids and lignin was observed when MeJA (100 mM) was used as an elicitor, following a 72-h treatment period. Hence, for different plant metabolites, the treatment with meJA (100 µM/L) and a co-treatment of MeJA and AgNPs (100 µM/L + 1 µg/L) under prolonged exposure times of 120-144 h proved to be the most promising in the accretion of valuable bioactive molecules. The study opens new insights into the use of these elicitors, individually or in combination, by using different concentrations and compositions

Enhanced Production of Active Photosynthetic and Biochemical Molecules in <i>Silybum marianum</i> L. Using Biotic and Abiotic Elicitors in Hydroponic Culture

Elicitors are stressors that activate secondary pathways that lead to the increased production of bioactive molecules in plants. Different elicitors including the fungus Aspergillus niger (0.2 g/L), methyl jasmonate (MeJA, 100 µM/L), and silver nanoparticles (1 µg/L) were added, individually and in combination, in a hydroponic medium. The application of these elicitors in hydroponic culture significantly increased the concentration of photosynthetic pigments and total phenolic contents. The treatment with MeJA (methyl jasmonate) (100 µM/L) and the co-treatment of MeJA and AgNPs (silver nanoparticles) (100 µM/L + 1 µg/L) exhibited the highest chlorophyll a (29 µg g−1 FW) and chlorophyll b (33.6 µg g−1 FW) contents, respectively. The elicitor MeJA (100 µM/L) gave a substantial rise in chlorophyll a and b and total chlorophyll contents. Likewise, a significant rise in carotenoid contents (9 µg/g FW) was also observed when subjected to meJA (100 µM/L). For the phenolic content, the treatment with meJA (100 µM/L) proved to be very effective. Nevertheless, the highest production (431 µg/g FW) was observed when treated with AgNPs (1 µg/L). The treatments with various elicitors in this study had a significant effect on flavonoid and lignin content. The highest concentration of flavonoids and lignin was observed when MeJA (100 mM) was used as an elicitor, following a 72-h treatment period. Hence, for different plant metabolites, the treatment with meJA (100 µM/L) and a co-treatment of MeJA and AgNPs (100 µM/L + 1 µg/L) under prolonged exposure times of 120–144 h proved to be the most promising in the accretion of valuable bioactive molecules. The study opens new insights into the use of these elicitors, individually or in combination, by using different concentrations and compositions

Citrus Canker—Distribution, Taxonomy, Epidemiology, Disease Cycle, Pathogen Biology, Detection, and Management: A Critical Review and Future Research Agenda

Xanthomonas citri subsp. citri, a causative agent of the citrus canker (CC) disease, belongs to one of the essential groups of the bacterial phytopathogen family, Xanthomonadaceae. It has been a potential threat to the globally significant citrus fruit crop, which has remained under investigation for disease management and epidemiology since the 1980s. In Pakistan, the average yield of citrus is 11 t/ha, which is lower than other countries, including China, Brazil, and India, having average productions of 27, 26, and 22 tons/hectare, respectively. Citrus canker is one of the most devastating diseases, posing a significant threat to crop yield and fruit quality. To date, five distinct types (or forms) of the citrus canker have been recognized; the Asiatic (Canker A) form is most destructive and affects most citrus cultivars. Severe infection outcomes include dieback, defoliation, severely blemished fruit, premature fruit drop, and reduced fruit quality. The infection increases under humid, warm, cloudy climate, wind, and heavy rainfall. The analysis of plasmid and chromosomal DNA of X. citri subsp. citri depicted an evolutionary relationship among pathovars of Xanthomonas. The extensive study on the genome of X. citri subsp. citri has contributed to the current knowledge of plant host recognition of pathogens, host specificities, dissemination, and propagation. Regulatory programs, i.e., quarantine or exclusion, continued to be practiced, prohibiting infected citrus plant material into the existing stock. Other measures include removal of inoculums sources, resistant hosts, protective copper-containing sprays, and windbreak systems. In this review, we explored the latest trends in the areas of epidemiology, pathogenome, detection, host–pathogen interaction, biofilm formation, and management of X. citri subsp. citri

Enhanced Production of Active Photosynthetic and Biochemical Molecules in L. Using Biotic and Abiotic Elicitors in Hydroponic Culture.

Elicitors are stressors that activate secondary pathways that lead to the increased production of bioactive molecules in plants. Different elicitors including the fungus Aspergillus niger (0.2 g/L), methyl jasmonate (MeJA, 100 µM/L), and silver nanoparticles (1 µg/L) were added, individually and in combination, in a hydroponic medium. The application of these elicitors in hydroponic culture significantly increased the concentration of photosynthetic pigments and total phenolic contents. The treatment with MeJA (methyl jasmonate) (100 µM/L) and the co-treatment of MeJA and AgNPs (silver nanoparticles) (100 µM/L + 1 µg/L) exhibited the highest chlorophyll a (29 µg g-1 FW) and chlorophyll b (33.6 µg g-1 FW) contents, respectively. The elicitor MeJA (100 µM/L) gave a substantial rise in chlorophyll a and b and total chlorophyll contents. Likewise, a significant rise in carotenoid contents (9 µg/g FW) was also observed when subjected to meJA (100 µM/L). For the phenolic content, the treatment with meJA (100 µM/L) proved to be very effective. Nevertheless, the highest production (431 µg/g FW) was observed when treated with AgNPs (1 µg/L). The treatments with various elicitors in this study had a significant effect on flavonoid and lignin content. The highest concentration of flavonoids and lignin was observed when MeJA (100 mM) was used as an elicitor, following a 72-h treatment period. Hence, for different plant metabolites, the treatment with meJA (100 µM/L) and a co-treatment of MeJA and AgNPs (100 µM/L + 1 µg/L) under prolonged exposure times of 120-144 h proved to be the most promising in the accretion of valuable bioactive molecules. The study opens new insights into the use of these elicitors, individually or in combination, by using different concentrations and compositions