Plant Biology Research Papers - Academia.edu (original) (raw)
Conventional methods to detect and assess the viability of plant pathogenic bacteria are usually based on plating assays or serological techniques. Plating assays provide information about the number of viable cells, expressed as... more
Conventional methods to detect and assess the viability of plant pathogenic bacteria are usually based on plating assays or serological techniques. Plating assays provide information about the number of viable cells, expressed as colony-forming units, but are time-consuming and laborious. Serological methods, such as the enzyme-linked immunosorbent assay (ELISA) and immunofluorescence microscopy (IF), can be performed in a shorter timespan than most plating assays, but they do not discriminate between live and dead cells. Flow cytometry (FCM) in combination with fluorescent probe technology is a rapid, sensitive, and quantitative technique to detect microorganisms and assess their viability. Quantitative information on the presence and viability of plant pathogenic microorganisms is valuable for risk assessment regarding disease transmission and disease development. FCM has been applied successfully in the fields of food microbiology, veterinary science, and medical research to dete...
Bacterial resistance to antibiotics continues to be a grave threat to human health. Because antibiotics are no longer a lucrative market for pharmaceutical companies, the development of new antibiotics has slowed to a crawl. The World... more
Bacterial resistance to antibiotics continues to be a grave threat to human health. Because antibiotics are no longer a lucrative market for pharmaceutical companies, the development of new antibiotics has slowed to a crawl. The World Health Organization reported that the 8 new bacterial agents approved since July 2017 had limited clinical benefits. While a cohort of biopharmaceutical companies recently announced plans to develop 2-4 new antibiotics by 2030, we needn’t wait a decade to find innovative antibiotic candidates. Essential oils (EOs) have long been known as antibacterial agents with wide-ranging arsenals. Many are able to penetrate the bacterial membrane and may also be effective against bacterial defenses such as biofilms, efflux pumps, and quorum sensing. EOs have been documented to fight drug-resistant bacteria alone and/or combined with antibiotics. This review will summarize research showing the significant role of EOs as nonconventional regimens against the worldwid...
Callus induction from petiole explants has been achieved in Alocasia micholitziana `Green Velvet'. The highest percentage (71%) of explants inducing callus was obtained on MS medium supplemented with 0.5 μM 2,4-D and 0.5 μM kinetin in the... more
Callus induction from petiole explants has been achieved in Alocasia micholitziana `Green Velvet'. The highest percentage (71%) of explants inducing callus was obtained on MS medium supplemented with 0.5 μM 2,4-D and 0.5 μM kinetin in the dark after 4 months of culture. Shoots were regenerated at the highest frequency of 33.3% under light condition when 0.5 μM BA was added to MS medium with the average of 7.8±2.3 shoots per callus explant. The callus-derived shoots rooted on hormone free MS medium and within 4 weeks the plantlets were ready for acclimatization. The regenerated plants appeared morphologically similar to mother plants.
Plants are fundamentally important to life. Key research areas in plant science include plant species identification, weed classification using hyper spectral images, monitoring plant health and tracing leaf growth, and the semantic... more
Plants are fundamentally important to life. Key research areas in plant science include plant species identification, weed classification using hyper spectral images, monitoring plant health and tracing leaf growth, and the semantic interpretation of leaf information. Botanists easily identify plant species by discriminating between the shape of the leaf, tip, base, leaf margin and leaf vein, as well as the texture of the leaf and the arrangement of leaflets of compound leaves. Because of the increasing demand for experts and calls for biodiversity, there is a need for intelligent systems that recognize and characterize leaves so as to scrutinize a particular species, the diseases that affect them, the pattern of leaf growth, and so on. We review several image processing methods in the feature extraction of leaves, given that feature extraction is a crucial technique in computer vision. As computers cannot comprehend images, they are required to be converted into features by individually analyzing image shapes, colors, textures and moments. Images that look the same may deviate in terms of geometric and photometric variations. In our study, we also discuss certain machine learning classifiers for an analysis of different species of leaves.
Plants deploy a finely tuned balance between growth and defence responses for better fitness. Crosstalk between defence signalling hormones such as salicylic acid (SA) and jasmonates (JAs) as well as growth regulators plays a significant... more
Plants deploy a finely tuned balance between growth and defence responses for better fitness. Crosstalk between defence signalling hormones such as salicylic acid (SA) and jasmonates (JAs) as well as growth regulators plays a significant role in mediating the trade-off between growth and defence in plants. Here, we specifically discuss how the mutual antagonism between the signalling of auxin and SA impacts on plant growth and defence. Furthermore, the synergism between auxin and JA benefits a class of plant pathogens. JA signalling also poses growth cuts through auxin. We discuss how the effect of cytokinins (CKs) is multifaceted and is effective against a broad range of pathogens in mediating immunity. The synergism between CKs and SA promotes defence against biotrophs. Reciprocally, SA inhibits CK-mediated growth responses. Recent reports show that CKs promote JA responses; however, in a feedback loop, JA suppresses CK responses. We also highlight crosstalk between auxin and CKs ...
A typical character of plants is the production and storage of usually complex mixtures of secondary metabolites (SM). The main function of secondary metabolites is defense against herbivores and microbes; some SM are signal compounds to... more
A typical character of plants is the production and storage of usually complex mixtures of secondary metabolites (SM). The main function of secondary metabolites is defense against herbivores and microbes; some SM are signal compounds to attract pollinating and seed dispersing animals or play a role in the symbiotic relationships with plants and microbes. The distribution of SM in the plant kingdom shows an interesting pattern. A specific SM is often confined to a particular systematic unit, but isolated occurrences can occur in widely unrelated taxonomic groups. This review tries to explain the patchy occurrence of SM in plants. It could be due to convergent evolution, but evidence is provided that the genes that encode the biosynthesis of SM appear to have a much wider distribution than the actual secondary metabolite. It seems to be rather a matter of differential gene regulation whether a pathway is active and expressed in a given taxonomic unit or not. It is speculated that the...
Gouania longipetala is commonly used in Cameroonian traditional medicine to manage women fertility and menopausal complaints. However, despite this use, the estrogenic properties of Gouania longipetala (G. longipetala) have not been... more
Gouania longipetala is commonly used in Cameroonian traditional medicine to manage women fertility and menopausal complaints. However, despite this use, the estrogenic properties of Gouania longipetala (G. longipetala) have not been studied until now. The present study was aimed to assess estrogenic activities of the stem bark aqueous (GLA) and ethanolic (GLE) extracts of G. longipetala in post menopause-like model of ovariectomized (Ovx) Wistar rats. Animals were either sham-operated or Ovx. 84 days after ovariectomy, animals were divided into seven groups of five animals and were daily treated for 28 days with distilled water (10mL/kg) for group 1, 2% solution of Tween 80 (10mL/kg) for group 2, estradiol valerate (1mg/kg) for group 3, GLA (45 or 180mg/kg) and GLE (40 or 160mg/kg) for groups 4 to 7 respectively. Sham-operated animals daily received distilled water (10mL/kg). During the experimental period, the body weight was registered every week. At the day 29, blood pressure was registered by invasive method while uterine and vagina morphometry as well as body, uterine and abdominal fat weights changes were analyzed. Serum levels of total cholesterol, triglycerides, HDL-cholesterol and LDL-cholesterol were determined. Moreover, oxidative stress markers such as nitrites, reduced glutathione (GSH) and malondialdehyde (MDA) were measured in homogenized liver and aorta. Compared with the sham control, vagina and uterine dystrophy and elevated blood pressure were observed in Ovx rats treated with vehicles. Biochemical parameters showed a significant increase of total cholesterol, triglycerides, LDL-cholesterol and MDA as well as a significant decrease of nitrites and GSH in Ovx animals treated with vehicle as compared to sham group. GLA and GLE displayed estrogen-like effects on vagina and did not affect uterine wet weight and epithelial height compared with vehicle groups. Both extracts displayed anti-atherogenic properties by reducing AI, AIP and LDL-cholesterol level as compared to vehicles groups. GLA and GLE significantly prevented the increase of MDA induced by ovariectomy as compared to rats treated with vehicles. This study showed that GLA and GLE exhibited estrogenic effects by providing vaginal lubrication, by modulating blood pressure and improving lipid profile, oxidative status and endothelial function and may not have an undesirable influence on the endometrium in ovariectomized rats.
Weeds reduce crop productivity through competion for nutrients, water, light and space, and impact negatively on commercial crops. Honeybush tea (Cyclopia spp.) is an industry mainly focused on the organic cultivation of tea, using... more
Weeds reduce crop productivity through competion for nutrients, water, light and space, and impact negatively on commercial crops. Honeybush tea (Cyclopia spp.) is an industry mainly focused on the organic cultivation of tea, using mechanical weeding control methods. To date, no studies have investigated the impact of weeds in honeybush plantations This study quantified the impact weeds have on honeybush plant survival, growth, yield, and economic value in order to identify a cost-effective and efficient integrated weed management system. Impacts of different weeding treatments were assessed at harvest on Cyclopia subternata Vogel 18 months after planting. The use of a synthetic woven mulch in combination with inter-row weeding resulted in significantly higher yield, larger plants, best growth rate and reduced weed biomass. Crop survival under this treatment was also greatly improved.