The Effect of Salicylic Acid on Response to Water Deficit in Basil

Drought-induced stress is the main limiting factor that affects growth and development in plants. In this study, the effect of exogenous application of salicylic acid (SA) on drought tolerance in basil was investigated. The analysis showed that application of SA under drought stress had significant effects on physiological and biochemical parameters, such as photosynthetic pigments content, total phenolics, flavonoids, flavanols and protein content and peroxidise activity, but had no significant effects on the morphological parameters, such as stem length, length and areaof leaves . In drought conditions, total phenolics and peroxidase activity reduced significantly, but all photosynthetic pigments, total flavonoids, flavanols and proteins increased significantly. Application of SA displayed some alleviating effects against drought induced stress through increase of plant growth, total flavonoids content and peroxidase activit

Growth, secondary metabolites production, antioxidative and antimicrobial activity of mint under the influence of plant growth regulators

The effects of plant growth regulators on Mentha piperita explants cultured in vitro were studied for the purpose of analyse growth, secondary metabolite production, antioxidant and antimicrobial activities in micropropagated plants. The basal medium was experimentally supplemented with the auxin, indole-3-butyric acid (IBA) and the cytokinin, N6- benzyladenine (BAP) individually and in combination. Treatment with BAP and IBA resulted in an increased shoot and root number. The production of phenolic compounds was affected by the addition of the highest concentration of BAP, while antioxidant and antimicrobial activities were affected by several BAP and IBA treatments. Our results demonstrate that the application of growth regulators increases growth and secondary metabolite productions in the medicinal herb M. piperita

Media composition affects seed dormancy, apical dominance and phenolic profile of Knautia sarajevensis (Dipsacaceae), Bosnian endemic

Knautia sarajevensis is an endemic plant of the Dinaric Alps and is mainly distributed on Bosnian Mountains. Due to the quite large flower heads and easy maintenance, this plant has a potential use as a substitute ornamental plant for K. arvensis in perennial beds. The current study evaluated the germination process in different treatments in an attempt to suppress dormancy and increase germination rate, and to develop a successful protocol for micropropagation. An over 60% germination rate was achieved through cultivation of seeds on MS basal medium with reduced mineral nutrient composition and the absence of sucrose. On the other hand, a below 10% germination rate was achieved with untreated seeds. Suppression of apical dominance was achieved through application of high concentrations of kinetin, apical shoot decapitation or cultivation of shoots in liquid media. Overall, liquid cultures were more successful as a micropropagation system for this plant. Shoots spontaneously developed roots on multiplication treatments and were successfully acclimatized. Moreover, phenolic compound profile was analysed in the light of the possible medicinal potential of this plant. Variable amounts of total phenolic compounds as well as individual phenolics were recorded, according to treatment and solidification of media. An increase in rosmarinic acid content was reported for kinetin treatments and acclimatized plants comparing to mother plants in natural habitat. The present study shows that choice of cytokinin concentration, explant type as well as culture type influences not only shoot proliferation and apical dominance suppression but also in vitro production of phenolics

Aconitum lycoctonum L.: Phenolic Compounds and Their Bioactivities

The very first report on the phenolic composition of aerial parts of Aconitum lycoctonum L., a species belonging to the toxic Aconitum genus, is presented here. Aerial parts were subjected to the extraction with four different solvents and analyzed via LC-MS/MS for the content of phenolic acids and flavonoids. Furthermore, isolated extracts were tested for antimicrobial and antioxidant activities. Ethanolic extracts of both flowers and vegetative parts (leaves and stems) were found to be the richest in the phenolic compounds, following the water extracts. Ethanolic extract of flowers was very rich in flavonoid apigenin, while high levels of salicylic and 4-hydroxybenzoic acids were found in the same extract of leaves and stems. On contrary, water extract contained significant amounts of kaempferol and rosmarinic acid. All extracts showed potent antioxidant activity, which is correlated with the content of phenolics. The antimicrobial assay showed that all extracts, except aqueous, were quite potent against all microbial organisms tested

Effect of salicylic acid seed priming on resistance to high levels of cadmium in lettuce (Lactuca sativa L.)

Cadmium (Cd) is abundant heavy metal with highly toxic effect on plants. The aim of presented study was to investigate the effect of seed priming using salicylic acid on cadmium tolerance in lettuce. The tolerance level was evaluated using germination speed and percentage, fresh and dry seedling weight, water and photosynthetic pigments content. Control seeds were primed using distilled water. In control plants cadmium induced reduction of germination rate, fresh and dry weight, water and chlorophyll content. Seed priming using salicylic acid, on the other hand, induced increased resistance of lettuce to cadmium toxicity. Increase in germination rate, fresh mass and water content were recorded for plants subjected to 5 mM Cd, grown from seeds primed using salicylic acid. Results obtained by this study suggested that salicylic acid can be used as priming agent in order to alleviate Cd toxicity on lettuce

Effects of short-term xposure to low temperatures on proline, pigments, and phytochemicals level in kale (Brassica oleracea var. acephala)

Kale (Brassica oleracea var acephala) is known as a vegetable with good tolerance of environmental stress and numerous beneficial properties for human health, which are attributed to different phytochemicals. In the present study, investigation of how low temperatures affect proline, pigments and specialized metabolites content was performed using 8-weeks old kale plants subjected to chilling (at 8 °C, for 24 h) followed by short freezing (at −8 °C, for 1 h after previous acclimation at 8 °C, for 23 h). Plants growing at 21 °C served as a control. In both groups of plants (exposed to low temperatures and exposed to short freezing) a significant increase in proline content (14% and 49%, respectively) was recorded. Low temperatures (8 °C) induced an increase of pigments (total chlorophylls 7%) and phytochemicals (phenolic acids 3% ; flavonoids 5% ; carotenoids 15% ; glucosinolates 21%) content, while exposure to freezing showed a different trend dependent upon observed parameter. After freezing, the content of chlorophylls, carotenoids, and total phenolic acids retained similar levels as in control plants and amounted to 14.65 ± 0.36 mg dw g−1, 2.58 ± 0.05 mg dw g−1 and 13.75 ± 0.07 mg dw CEA g−1, respectively. At the freezing temperature, total polyphenol content increased 13% and total flavonoids and glucosinolates content decreased 21% and 54%, respectively. Our results suggest that acclimatization (23 h at 8 °C) of kale plants can be beneficial for the accumulation of pigments and phytochemicals, while freezing temperatures affect differently specialized metabolite synthesis. The study suggests that growing temperature during kale cultivation must be considered as an important parameter for producers that are orientated towards production of crops with an increasing content of health- related compounds

Biochemical responses of basil to aluminium and cadmium stresses

The effect of aluminium and cadmium on growth and physiological parameters in 60 days old basil seedlings (Ocimum basilicum L.) grown in polluted soil were investigated. Control plants, grown in unpolluted soil, were used for evaluation of the heavy metal effect. Growth parameters were analysed immediately after sample collection, leaf area and plant height were recorded. Analysis of secondary metabolite, proline, total carbohydrates content and antioxidant capacity in 60 days old seedlings was performed. The antioxidant activity of basil extracts was determined by the DPPH method, and results showed an increase of antioxidative capacity in basil seedlings exposed to heavy metal stress due to the activation of antioxidative system in plant cells. Maximum production of secondary metabolites was recorded for seedlings exposed to 100 mg/kg soil Cd and Al. Results showed that cadmium stress increased concentration of proline, while aluminium did not had that effect. The content of total carbohydrates remained almost unchanged, with exception of basil seedlings grown on soil containing 50mg/kg AlCl3

AIR POLLUTION TOLERANCE INDEX OF Plantago major IN STEELWORKS AREA OF ZENICA, BOSNIA AND HERZEGOVINA

Atmospheric pollution is among the largest anthropogenic impacts on the ecosystem. In numerous studies it was observed that plants, especially those that grow in urban areas, are heavily influenced by different pollutants and their survival is correlated with structural and metabolic adaptation to stressful environmental conditions. Primary objective of this study was to determine the index of tolerance to air pollution (APTI) of plantain (Plantago major), on two locations in Zenica. The results indicated that index of tolerance to air pollution of P. major, APTI, is higher in individuals sampled from the contaminated site, than those in the control area

Beneficial Microbes and Molecules for Mitigation of Soil Salinity in Brassica Species: A Review

Salt stress results from excessive salt accumulation in the soil can lead to a reduction in plant growth and yield. Due to climate change, in the future climatic pressures, changed precipitation cycles and increased temperature will increase the pressures on agriculture, including increasing severity of salt stress. Brassica species contains oilseed and vegetable crops with great economic importance. Advances in understanding the mechanisms of salt stress in Brassica plants have enabled the development of approaches to better induce plant defense mechanisms at the time of their occurrence through the use of beneficial microorganisms or molecules. Both endophytic and rhizospheric microbes contribute to the mitigation of abiotic stresses in Brassica plants by promoting the growth of their host under stress conditions. In this review we summarized so far reported microorganisms with beneficial effects on Brassica plants and their mode of action. Another approach in mitigating the harmful effect of soil salinity may involve the application of different molecules that are involved in the stress response of Brassica plants. We reviewed and summarized their potential mode of action, methods of application and pointed out further research directions

Use of seed priming to improve Cd accumulation and tolerance in Silene sendtneri, novel Cd hyper-accumulator

Changes in the environment as a result of industrialisation and urbanisation impact negatively on plant growth and crop production. Cadmium (Cd) is one of the most dangerous metals that enters the food chain, with toxic effects on plants and human health. This study evaluated the potential of Silene sendtneri as a novel hyperaccumulator and the role of seed priming in tolerance and accumulation rate of Cd. The effect of different priming agents on germination performance, root growth, seedling development, metal uptake and accumulation, antioxidant defences including enzymatic and non-enzymatic antioxidants has been assessed. Seed priming using silicic acid, proline alone or in combination with salicylic acidenhanced germination, seedling development, and root growth under Cd stress. The same priming treatments induced an increase of water content in shoots and roots when plants were exposed to Cd. The enzymatic antioxidant response was specific for the priming agent used. An increase in ferulic acid and rutin in shoots was related to the increase of Cd concentration in the medium. The concentration of malic and oxalic acid increased significantly in shoots of plants grown on high Cd concentrations compared to low Cd concentrations. Silene sendtneri can accumulate significant levels of Cd with enhanced accumulation rate and tolerance when seeds are primed. The best results are obtained by seed priming using 1% silicic acid, proline and salicylic acid