Hormonal and proteomic analyses of southern blight disease caused by Athelia rolfsii and root chitosan priming on Cannabis sativa in an in vitro hydroponic system.

Southern blight disease, caused by the fungal pathogen Athelia rolfsii, suppresses plant growth and reduces product yield in Cannabis sativa agriculture. Mechanisms of pathology of this soil-borne disease remain poorly understood, with disease management strategies reliant upon broad-spectrum antifungal use. Exposure to chitosan, a natural elicitor, has been proposed as an alternative method to control diverse fungal diseases in an eco-friendly manner. In this study, C. sativa plants were grown in the Root-TRAPR system, a transparent hydroponic growth device, where plant roots were primed with .2% colloidal chitosan prior to A. rolfsii inoculation. Both chitosan-primed and unprimed inoculated plants displayed classical symptoms of wilting and yellowish leaves, indicating successful infection. Non-primed infected plants showed increased shoot defense responses with doubling of peroxidase and chitinase activities. The levels of growth and defense hormones including auxin, cytokinin, and jasmonic acid were increased 2-5-fold. In chitosan-primed infected plants, shoot peroxidase activity and phytohormone levels were decreased 1.5-4-fold relative to the unprimed infected plants. When compared with shoots, roots were less impacted by A. rolfsii infection, but the pathogen secreted cell wall-degrading enzymes into the root-growth solution. Chitosan priming inhibited root growth, with root lengths of chitosan-primed plants approximately 65% shorter than the control, but activated root defense responses, with root peroxidase activity increased 2.7-fold along with increased secretion of defense proteins. The results suggest that chitosan could be an alternative platform to manage southern blight disease in C. sativa cultivation; however, further optimization is required to maximize effectiveness of chitosan.

Effects of chitin and chitosan on root growth, biochemical defense response and exudate proteome of Cannabis sativa.

Fungal pathogens pose a major threat to Cannabis sativa production, requiring safe and effective management procedures to control disease. Chitin and chitosan are natural molecules that elicit plant defense responses. Investigation of their effects on C. sativa will advance understanding of plant responses towards elicitors and provide a potential pathway to enhance plant resistance against diseases. Plants were grown in the in vitro Root-TRAPR system and treated with colloidal chitin and chitosan. Plant morphology was monitored, then plant tissues and exudates were collected for enzymatic activity assays, phytohormone quantification, qPCR analysis and proteomics profiling. Chitosan treatments showed increased total chitinase activity and expression of pathogenesis-related (PR) genes by 3-5 times in the root tissues. In the exudates, total peroxidase and chitinase activities and levels of defense proteins such as PR protein 1 and endochitinase 2 were increased. Shoot development was unaffected, but root development was inhibited after chitosan exposure. In contrast, chitin treatments had no significant impact on any defense parameters, including enzymatic activities, hormone quantities, gene expression levels and root secreted proteins. These results indicate that colloidal chitosan, significantly enhancing defense responses in C. sativa root system, could be used as a potential elicitor, particularly in hydroponic scenarios to manage crop diseases.

Utilisation of QSPR ODT modelling and odour vector modelling to predict Cannabis sativa odour.

Cannabis flower odour is an important aspect of product quality as it impacts the sensory experience when administered, which can affect therapeutic outcomes in paediatric patient populations who may reject unpalatable products. However, the cannabis industry has a reputation for having products with inconsistent odour descriptions and misattributed strain names due to the costly and laborious nature of sensory testing. Herein, we evaluate the potential of using odour vector modelling for predicting the odour intensity of cannabis products. Odour vector modelling is proposed as a process for transforming routinely produced volatile profiles into odour intensity (OI) profiles which are hypothesised to be more informative to the overall product odour (sensory descriptor; SD). However, the calculation of OI requires compound odour detection thresholds (ODT), which are not available for many of the compounds present in natural volatile profiles. Accordingly, to apply the odour vector modelling process to cannabis, a QSPR statistical model was first produced to predict ODT from physicochemical properties. The model presented herein was produced by polynomial regression with 10-fold cross-validation from 1,274 median ODT values to produce a model with R2 = 0.6892 and a 10-fold R2 = 0.6484. This model was then applied to terpenes which lacked experimentally determined ODT values to facilitate vector modelling of cannabis OI profiles. Logistic regression and k-means unsupervised cluster analysis was applied to both the raw terpene data and the transformed OI profiles to predict the SD of 265 cannabis samples and the accuracy of the predictions across the two datasets was compared. Out of the 13 SD categories modelled, OI profiles performed equally well or better than the volatile profiles for 11 of the SD, and across all SD the OI data was on average 21.9% more accurate (p = 0.031). The work herein is the first example of the application of odour vector modelling to complex volatile profiles of natural products and demonstrates the utility of OI profiles for the prediction of cannabis odour. These findings advance both the understanding of the odour modelling process which has previously only been applied to simple mixtures, and the cannabis industry which can utilise this process for more accurate prediction of cannabis odour and thereby reduce unpleasant patient experiences.

Root-TRAPR: a modular plant growth device to visualize root development and monitor growth parameters, as applied to an elicitor response of Cannabis sativa.

BACKGROUND: Plant growth devices, for example, rhizoponics, rhizoboxes, and ecosystem fabrication (EcoFAB), have been developed to facilitate studies of plant root morphology and plant-microbe interactions in controlled laboratory settings. However, several of these designs are suitable only for studying small model plants such as Arabidopsis thaliana and Brachypodium distachyon and therefore require modification to be extended to larger plant species like crop plants. In addition, specific tools and technical skills needed for fabricating these devices may not be available to researchers. Hence, this study aimed to establish an alternative protocol to generate a larger, modular and reusable plant growth device based on different available resources. RESULTS: Root-TRAPR (Root-Transparent, Reusable, Affordable three-dimensional Printed Rhizo-hydroponic) system was successfully developed. It consists of two main parts, an internal root growth chamber and an external structural frame. The internal root growth chamber comprises a polydimethylsiloxane (PDMS) gasket, microscope slide and acrylic sheet, while the external frame is printed from a three-dimensional (3D) printer and secured with nylon screws. To test the efficiency and applicability of the system, industrial hemp (Cannabis sativa) was grown with or without exposure to chitosan, a well-known plant elicitor used for stimulating plant defense. Plant root morphology was detected in the system, and plant tissues were easily collected and processed to examine plant biological responses. Upon chitosan treatment, chitinase and peroxidase activities increased in root tissues (1.7- and 2.3-fold, respectively) and exudates (7.2- and 21.6-fold, respectively). In addition, root to shoot ratio of phytohormone contents were increased in response to chitosan. Within 2 weeks of observation, hemp plants exhibited dwarf growth in the Root-TRAPR system, easing plant handling and allowing increased replication under limited growing space. CONCLUSION: The Root-TRAPR system facilitates the exploration of root morphology and root exudate of C. sativa under controlled conditions and at a smaller scale. The device is easy to fabricate and applicable for investigating plant responses toward elicitor challenge. In addition, this fabrication protocol is adaptable to study other plants and can be applied to investigate plant physiology in different biological contexts, such as plant responses against biotic and abiotic stresses.

Severe Trichotillomania: An Unusual Trigger of Recurrent Diabetic Ketoacidosis.

Diabetic ketoacidosis (DKA) is a life-threatening complication of diabetes that is most often seen in patients with type 1 diabetes mellitus. Current DKA management focuses on rapid treatment to prevent acute complications, educational intervention, and early discharge. However, patients with mental health conditions face additional barriers to establishing control over their diabetes and may be hospitalized often for DKA recurrence. Understanding a patient's mental health and intervening where necessary may be a crucial step in the effective treatment of DKA. We present a case of recurrent DKA in a young male who suffered from severe trichotillomania. Trichotillomania is a mental health disorder in which an individual has the compulsion to pull on hair because it feels good. By doing so, the skin barrier is compromised. This can lead to disfiguring lesions that can be very distressing for the individual; however, they report an inability to control the compulsion to stop pulling their hair. In our case, the patient disrupted the skin barrier, leading to increased susceptibility for recurrent infection and DKA.

Pharmacokinetic properties of phytochemicals in Hypericum perforatum influence efficacy of regulating oxidative stress.

BACKGROUND: Hypericum perforatum is used in ethnopharmacology and has recently become popular in conventional medicine for treatment of mild to moderate depression. The abundance of potentially functional phytochemicals and their broader utilizations in traditional medicine suggests that ingestion of H. perforatum may impart additional secondary health benefits. HYPOTHESIS/PURPOSE: Considering that many phytochemicals are known to display antioxidant activity, it was hypothesized that H. perforatum ingestion may inhibit oxidative stress and inflammation (OSI) which occurs in transient cycles following exercise and consumption of meals. The aim of this study was to explore the pharmacokinetics of H. perforatum phytochemicals after ingestion to predict the absorption timing of putative medicinal phytochemicals. STUDY DESIGN/METHODS: In silico analyses of previously published plant extract phytochemical profiles were performed, wherein the Phytochemical Absorption Prediction (PCAP) model was used to predict the pharmacokinetics of phytochemicals. The predicted times for phytochemicals to reach maximum plasma concentration (Tmax), and associated antioxidant activities, were compared to prior clinical in vivo studies to assess the accuracy and applicability of predictions. RESULTS: The PCAP model identified that phytochemicals with antioxidant activity concurrently accumulate in plasma with Tmax in the range of 1.6-2.3 h after ingestion. Comparison with previously published results identified that attenuation of OSI following H. perforatum ingestion aligns with the predicted Tmax of antioxidant phytochemicals. CONCLUSION: Based on these results it is therefore recommended that H. perforatum administration occurs 2 h before meals to provide optimal secondary health benefits associated with inhibition of postprandial stress. Additionally, these results highlight the use of in silico analyses to inform ingestion time and optimize the health benefits from ingestion of plant-based foods and medicines.

Diurnal Changes in Transcript and Metabolite Levels during the Iron Deficiency Response of Rice.

BACKGROUND: Rice (Oryza sativa L.) is highly susceptible to iron (Fe) deficiency due to low secretion levels of the mugineic acid (MA) family phytosiderophore (PS) 2'-deoxymugineic acid (DMA) into the rhizosphere. The low levels of DMA secreted by rice have proved challenging to measure and, therefore, the pattern of DMA secretion under Fe deficiency has been less extensively studied relative to other graminaceous monocot species that secrete high levels of PS, such as barley (Hordeum vulgare L.). RESULTS: Gene expression and metabolite analyses were used to characterise diurnal changes occurring during the Fe deficiency response of rice. Iron deficiency inducible genes involved in root DMA biosynthesis and secretion followed a diurnal pattern with peak induction occurring 3-5 h after the onset of light; a result consistent with that of other Strategy II plant species such as barley and wheat. Furthermore, triple quadrupole mass spectrometry identified 3-5 h after the onset of light as peak time of DMA secretion from Fe-deficient rice roots. Metabolite profiling identified accumulation of amines associated with metal chelation, metal translocation and plant oxidative stress responses occurring with peak induction 10-12 h after the onset of light. CONCLUSION: The results of this study confirmed that rice shares a similar peak time of Fe deficiency associated induction of DMA secretion compared to other Strategy II plant species but has less prominent daily fluctuations of DMA secretion. It also revealed metabolic changes associated with the remediation of Fe deficiency and mitigation of damage from resulting stress in rice roots. This study complements previous studies on the genetic changes in response to Fe deficiency in rice and constitutes an important advance towards our understanding of the molecular mechanisms underlying the rice Fe deficiency response.

Long-term methamphetamine administration in the vervet monkey models aspects of a human exposure: brain neurotoxicity and behavioral profiles.

Methamphetamine (METH)-associated alterations in the human striatal dopamine (DA) system have been identified with positron emission tomography (PET) imaging and post-mortem studies but have not been well correlated with behavioral changes or cumulative METH intake. Animal studies that model some aspects of human long-term METH abuse can establish dose-dependency profiles of both behavioral changes and potential brain neurotoxicities for identifying consequences of particular cumulative exposures. Based on parameters from human and our monkey pharmacokinetic studies, we modeled a prevalent human METH exposure of daily multiple doses in socially housed vervet monkeys. METH doses were escalated over 33 weeks, with final dosages resulting in estimated peak plasma METH concentrations of 1-3 microM, a range measured in human abusers. With larger METH doses, progressive increases in abnormal behavior and decreases in social behavior were observed on 'injection' days. Anxiety increased on 'no injection' days while aggression decreased throughout the study. Thereafter, during 3 weeks abstinence, differences in baseline vs post-METH behaviors were not observed. Post-mortem analysis of METH brains showed 20% lower striatal DA content while autoradiography studies of precommissural striatum showed 35% lower [3H]WIN35428 binding to the DA transporter. No statistically significant changes were detected for [3H]dihydrotetrabenazine binding to the vesicular monoamine transporter (METH-lower by 10%) or for [3H]SCH 23390 and [3H]raclopride binding to DA D1 and D2 receptors, respectively. Collectively, this long-term, escalating dose METH exposure modeling a human abuse pattern, not associated with high-dose binges, resulted in dose-dependent behavioral effects and caused persistent changes in presynaptic striatal DA system integrity.