43 research outputs found
Impact of vanadium stress on physiological and biochemical characteristics in heavy metal susceptible and tolerant Brassicaceae
>Magister Scientiae - MScThere is an influx in heavy metals into soils and ground water due to activities
such as increased mineral mining, improper watering and the use of heavy metal
contaminated fertilizers. These heavy metals are able to increase the ROS species
within plants which may result in plant metabolism deterioration and tissue
damage. Heavy metals may also directly damage plants by rendering important
enzymes non-functional through binding in metal binding sites of enzymes. The
heavy metal focused on in this study was vanadium due to South Africa being
one of the primary produces of this metal. Two related Brassica napus L cultivars
namely Agamax and Garnet which are economically and environmentally
important to South Africa were exposed to vanadium. Physiological experiments
such as cell death, chlorophyll and biomass determination were conducted to
understand how these cultivars were affected by vanadium toxicity. A low cost,
sensitive and robust vanadium assay was developed to estimate the amount of
vanadium in samples such as water, soils and plant material. The oxidative state
as well as the antioxidant profile of the two cultivars were also observed under
vanadium stress. A chlorophyll assay which was conducted on the two cultivars exposed to vanadium showed a marked decrease in chlorophyll A in the
suspected sensitive cultivar which was Garnet. However, the suspected tolerant
cultivar Agamax fared better and the decrease in chlorophyll A was much less. A
similar trend was observed for the two cultivars when the cell death assay was
conducted. The vanadium assay showed that Garnet had higher concentrations
of vanadium within its leaves and lower concentrations in its roots when
compared to Agamax. This observation displayed that Agamax had inherent
mechanisms which it used to localize vanadium in its roots and which assisted in
its tolerance to the vanadium stress.
The oxidative state was determined by doing assays for the specific reactive
oxygen species namely hydrogen peroxide and superoxide. It was observed that
vanadium treated Garnet leaves had higher reactive oxygen species (ROS)
production when compared to the Agamax treated leaves. In-gel native PAGE
activity gels were conducted to determine the antioxidant profile for the two
cultivars which were exposed to vanadium. The antioxidant enzymes which were
under investigation were ascorbate peroxide (APX), superoxide dismutase (SOD)
and glutathione-dependent peroxidases (GPX-like) as these enzymes are known
to be responsible for controlling the ROS produced in the plants. The GPX-like
profile consisted of three isoforms. No isoforms were inhibited by vanadium
treatments but one isoform had increased activity in both the Garnet and
Agamax treated samples. The SOD profile for Garnet consisted of six isoforms and Agamax had seven isoforms. One isoform which was visualized in both
Agamax as well as Garnet was inhibited by vanadium treatments. Agamax also
had two isoforms which were up-regulated however the corresponding isoforms
in Garnet showed no change. The Ascorbate peroxidase profile consisted of
seven isoforms for both Garnet and Agamax. No isoforms were inhibited by
vanadium treatment. Three isoforms were up-regulated in Garnet and Agamax
under vanadium treatments.
Here, it is illustrated that Garnet lacked certain mechanisms found in Agamax
(and thus experienced more cell death, yield and chlorophyll loss) and performed
worst under high vanadium concentrations. Although Garnet increased the
activity of some of its antioxidant isoforms in response to increasing ROS levels it
was not adequate to maintain a normal oxidative homeostasis. This disruption in
oxidative homeostasis lead to plant damage. Agamax was observed to produce
less ROS than Garnet and was able to control the ROS produced more effectively
than Garnet and thus less damage was observed in Agamax
3,3' Diindolylmethane mediated signalling and its role in Brassica napus L. responses to vanadium
Philosophiae Doctor - PhD (Biotechnology)Anthropogenic activities such as mineral mining, improper watering practices, and
the use of heavy metal contaminated fertilizers have caused an influx of heavy
metals into arable lands. These heavy metals may have a negative impact on plant
growth, as they are able to increase ROS species within plants resulting in plant
metabolism deterioration and tissue damage. Heavy metals also have the ability to
render important enzymes non-functional or may decrease their activity resulting in
poor growth. Vanadium was used as the heavy metal of choice in this study, as
South Africa is one of the top producers of this metal worldwide. In an effort to
improve growth of crop plants, mechanisms have to be identified to increase growth
under vanadium stress. One method to increase growth is the use of exogenously
applied signalling molecules. In this study, one such compound 3,3'
Diindolylmethane (DIM) was investigated to identify whether it had growth
promoting properties
Formulation and optimization of Aceclofenac gel
The present research work is to formulate and optimize Aceclofenac gel. Fourier Transfer Infrared Spectroscopy (FT-IR) study revealed no chemical interaction between drug and polymers. The formulations were prepared by using various polymers like Carbopol 934 and HPMC K15M. The formulated gels were evaluated for several physicochemical parameters like drug-polymer interaction, pH, Viscosity, Spredability, Drug content uniformity, In vitro drug release. The formulation F9 Showed maximum drug diffusion rate. The optimization study was carried out to find out effect of two independent variable on diffusion rate at 3 hour and diffusion rate at 6 hour. Optimization was performed by the help of software DESIGN EXPERT 8.0.6 trial. From this study, it was find out that as the concentration of polymer increases, the drug release will decreases
Piperonylic acid alters growth, mineral content accumulation and reactive oxygen species-scavenging capacity in chia seedlings
p-Coumaric acid synthesis in plants involves the conversion of phenylalanine to trans-cinnamic acid via phenylalanine ammonia-lyase (PAL),
which is then hydroxylated at the para-position under the action of trans-cinnamic acid 4-hydroxylase. Alternatively, some PAL enzymes accept
tyrosine as an alternative substrate and convert tyrosine directly to p-coumaric acid without the intermediary of trans-cinnamic acid. In recent
years, the contrasting roles of p-coumaric acid in regulating the growth and development of plants have been well-documented. To understand
the contribution of trans-cinnamic acid 4-hydroxylase activity in p-coumaric acid-mediated plant growth, mineral content accumulation and the
regulation of reactive oxygen species (ROS), we investigated the effect of piperonylic acid (a trans-cinnamic acid 4-hydroxylase inhibitor) on plant
growth, essential macroelements, osmolyte content, ROS-induced oxidative damage, antioxidant enzyme activities and phytohormone levels in
chia seedlings. Piperonylic acid restricted chia seedling growth by reducing shoot length, fresh weight, leaf area measurements and p-coumaric
acid content. Apart from sodium, piperonylic acid signifcantly reduced the accumulation of other essential macroelements (such as K, P, Ca and
Mg) relative to the untreated control. Enhanced proline, superoxide, hydrogen peroxide and malondialdehyde contents were observed. The inhibition of trans-cinnamic acid 4-hydroxylase activity signifcantly increased the enzymatic activities of ROS-scavenging enzymes such as superoxide dismutase, ascorbate peroxidase, catalase and guaiacol peroxidase. In addition, piperonylic acid caused a reduction in indole-3-acetic acid
and salicylic acid content. In conclusion, the reduction in chia seedling growth in response to piperonylic acid may be attributed to a reduction in
p-coumaric acid content coupled with elevated ROS-induced oxidative damage, and restricted mineral and phytohormone (indole-3-acetic acid
and salicylic) levels
Sustainable agriculture through the enhancement of microbial biocontrol agents: Current challenges and new perspectives
The future of pesticide usage in agriculture is uncertain due to its unsustainability, adverse
environmental impacts, and its association in enhanced phytopathogen resistance. Hence, this
situation urges the development of new sustainable practices in agriculture. A promising approach
involves endophytes, which are non-pathogenic microorganisms inhabiting the interior parts of plants.
However, due to the vast diversity and complexity of plant microbiomes, a major gap has formed with
regards to endophytic research and its application in phytopathogen biocontrol. The gap has mainly
been increasing due to the difficulty of isolating underrepresented endophytes and due to limitation
of previous genetic tools availability to further research and understand plant-microbe interaction,
endophytic biocontrol capabilities and their biocontrol compounds
Biomedical Relevance of Novel Anticancer Peptides in the Sensitive Treatment of Cancer
The global increase in cancer mortality and economic losses necessitates the cautious quest for therapeutic agents with compensatory advantages over conventional therapies. Anticancer peptides (ACPs) are a subset of host defense peptides, also known as antimicrobial peptides, which have emerged as therapeutic and diagnostic candidates due to several compensatory advantages over
the non-specificity of the current treatment regimens. This review aimed to highlight the ravaging incidence of cancer, the use of ACPs in cancer treatment with their mechanisms, ACP discovery and delivery methods, and the limitations for their use. This would create awareness for identifying more ACPs with better specificity, accuracy and sensitivity towards the disease. It would also promote their efficacious utilization in biotechnology, medical sciences and molecular biology to ease the severity of the disease and enable the patients living with these conditions to develop an accommodating lifestyle
Analytical studies of antimicrobial peptides as diagnostic biomarkers for the detection of bacterial and viral Pneumonia
Pneumonia remains one of the leading causes of infectious mortality and significant
economic losses among our growing population. The lack of specific biomarkers for correct and timely
diagnosis to detect patients’ status is a bane towards initiating a proper treatment plan for the disease;
thus, current biomarkers cannot distinguish between pneumonia and other associated conditions
such as atherosclerotic plaques and human immunodeficiency virus (HIV). Antimicrobial peptides
(AMPs) are potential candidates for detecting numerous illnesses due to their compensatory roles as
theranostic molecules. This research sought to generate specific data for parental AMPs to identify
viral and bacterial pneumonia pathogens using in silico technology
PR-1-Like Protein as a Potential Target for the Identification of Fusarium oxysporum: An In Silico Approach
Fusarium oxysporum remains one of the leading causes of economic losses and poor crop yields; its detection is strained due to its presentation in various morphological and physiological forms. This research work sought to identify novel biomarkers for the detection of Fusarium oxys porum using in silico approaches. Experimentally validated anti-Fusarium oxysporum antimicrobial peptides (AMPs) were used to construct a profile against Fusarium oxysporum. The performance and physicochemical parameters of these peptides were predicted. The gene for the Fusarium oxysporum receptor protein PR-1-like Protein, Fpr1, was identified and translated. The resulting protein model from the translation was then validated. The anti Fusarium oxysporum AMPs and Fusarium oxysporum receptor protein 3-D structures were characterized, and their docking interaction analyses were carried out. The HMMER in silico tool identified novel anti-Fusarium oxysporum antimicrobial peptides with good performance in terms of accuracy, sensitivity, and specificity. These AMPs also displayed good physicochemical properties and bound with greater affinity to Fusarium oxysporum protein receptor PR-1-like Protein. The tendency of these AMPs to precisely detect Fusarium oxysporum PR-1-like Protein, Fpr1, would justify their use for the identification of the fungus. This study would enhance and facilitate the identification of Fusarium oxysporum to reduce problems associated with poor crop yield, economic losses, and decreased nutritional values of plants to keep up with the
growing population
Efficient superoxide scavenging and metal immobilization in roots determines the level of tolerance to vanadium stress in two contrasting Brassica napus genotypes
Brassica napus also known as Rapeseed is a member of the Brassicaceae family which is mainly cultivated for its
oil-rich seeds. Indeed, B. napus is ranked the third-largest source of vegetable oil in the world. Brassica napus
growth, development and yield are negatively affected by heavy metals. Vanadium is a heavy metal and presence
in high concentrations impact plant growth and development negatively. However, the impact of Vanadium on B.
napus growth and development is unknown. Therefore, in this study we assessed the effects of Vanadium stress
on leaf physiology and biochemistry response of two B. napus cultivars (namely Agamax and AV Garnet). A
randomised pot-experiment under controlled conditions was used to grow B. napus cultivars under control (dis-
tilled water) and Vanadium (350 μM NaVO3) treatments. Results showed that Vanadium caused yellowing of AV
Garnet leaves but not Agamax leaves. Furthermore, Vanadium stress caused a more severe decrease in leaf dry
and fresh weight of AV Garnet as compared to the decrease in leaf dry and fresh weight of Agamax
Plant antimicrobial peptides (pamps): Features, applications, production, expression and challenges
The quest for an extraordinary array of defense strategies is imperative to reduce the challenges
of microbial attacks on plants and animals. Plant antimicrobial peptides (PAMPs) are a subset
of antimicrobial peptides (AMPs). PAMPs elicit defense against microbial attacks and prevent drug
resistance of pathogens given their wide spectrum activity, excellent structural stability, and diverse
mechanism of action. This review aimed to identify the applications, features, production, expression,
and challenges of PAMPs using its structure–activity relationship. The discovery techniques used
to identify these peptides were also explored to provide insight into their significance in genomics,
transcriptomics, proteomics, and their expression against disease-causing pathogens