Evaluation of the Glymphatic System in Schizophrenia Spectrum Disorder Using Proton Magnetic Resonance Spectroscopy Measurement of Brain Macromolecule and Diffusion Tensor Image Analysis Along the Perivascular Space Index.

BACKGROUND AND HYPOTHESIS: The glymphatic system (GS), a brain waste clearance pathway, is disrupted in various neurodegenerative and vascular diseases. As schizophrenia shares clinical characteristics with these conditions, we hypothesized GS disruptions in patients with schizophrenia spectrum disorder (SCZ-SD), reflected in increased brain macromolecule (MM) and decreased diffusion-tensor-image-analysis along the perivascular space (DTI-ALPS) index. STUDY DESIGN: Forty-seven healthy controls (HCs) and 103 patients with SCZ-SD were studied. Data included 135 proton magnetic resonance spectroscopy (1H-MRS) sets, 96 DTI sets, with 79 participants contributing both. MM levels were quantified in the dorsal-anterior cingulate cortex (dACC), dorsolateral prefrontal cortex, and dorsal caudate (point resolved spectroscopy, echo-time = 35ms). Diffusivities in the projection and association fibers near the lateral ventricle were measured to calculate DTI-ALPS indices. General linear models were performed, adjusting for age, sex, and smoking. Correlation analyses examined relationships with age, illness duration, and symptoms severity. STUDY RESULTS: MM levels were not different between patients and HCs. However, left, right, and bilateral DTI-ALPS indices were lower in patients compared with HCs (P < .001). In HCs, age was positively correlated with dACC MM and negatively correlated with left, right, and bilateral DTI-ALPS indices (P < .001). In patients, illness duration was positively correlated with dACC MM and negatively correlated with the right DTI-ALPS index (P < .05). In the entire population, dACC MM and DTI-ALPS indices showed an inverse correlation (P < .01). CONCLUSIONS: Our results suggest potential disruptions in the GS of patients with SCZ-SD. Improving brain's waste clearance may offer a potential therapeutic approach for patients with SCZ-SD.

Gastrointestinal bezoars: Review of the literature and report of a rare case of pumpkin seed rectal impaction.

In science, bezoar is a mass of hair or undigested vegetable matter, found in a human or animal's intestines, similar to a hairball. Usually, it is found trapped in every part of the gastrointestinal system and must be distinguished by pseudobezoar which is an indigestive object voluntarily introduced into the digestive tract. The term Bezoar is from Arabic bazahr, "bezoar" or ultimately from Middle Persian p'tzhl padzahr, "antidote, bezoar"ægagropile o egagropile It should be a universal antidote that works against any poison, and could neutralize any poison. Otherwise, the name could derive from a kind of Turkish goat whose name is just bezoar. Authors report a case of fecal impaction by pumpkin seeds bezoar with abdominal pain: a difficulty to void with subsequent rectal inflammation and hemorrhoid enlargement was observed. The patient underwent a successful manual disimpaction. Guidelines do not require IRB approval Authors examined the literature about occlusion from bezoar The most common causes of occlusion from bezoar are: a previous gastric surgery such as a gastric band (for weight loss) or gastric bypass, a reduced stomach acid (hypochlorhydria) or decreased stomach size, a delayed gastric emptying, typically due to diabetes, autoimmune disorders, or mixed connective tissue disease. Seed bezoars are usually found in the rectum of patients without predisposing factors, causing constipation and pain. Rectal impaction is common after ingestion of seeds while a true occlusion is rare. Although several cases of phytobezoars composed of various types of seeds are reported in literature, bezoars of pumpkin seeds have rarely been reported.

Assessment Tools of Biopsychosocial Frailty Dimensions in Community-Dwelling Older Adults: A Narrative Review.

Frailty is a complex interplay between several factors, including physiological changes in ageing, multimorbidities, malnutrition, living environment, genetics, and lifestyle. Early screening for frailty risk factors in community-dwelling older people allows for preventive interventions on the clinical and social determinants of frailty, which allows adverse events to be avoided. By conducting a narrative review of the literature employing the International Narrative Systematic Assessment tool, the authors aimed to develop an updated framework for the main measurement tools to assess frailty risks in older adults, paying attention to use in the community and primary care settings. This search focused on the biopsychosocial domains of frailty that are covered in the SUNFRAIL tool. The study selected 178 reviews (polypharmacy: 20; nutrition: 13; physical activity: 74; medical visits: 0; falls: 39; cognitive decline: 12; loneliness: 15; social support: 5; economic constraints: 0) published between January 2010 and December 2021. Within the selected reviews, 123 assessment tools were identified (polypharmacy: 15; nutrition: 15; physical activity: 25; medical visits: 0; falls: 26; cognitive decline: 18; loneliness: 9; social support: 15; economic constraints: 0). The narrative review allowed us to evaluate assessment tools of frailty domains to be adopted for multidimensional health promotion and prevention interventions in community and primary care.

A lesion-mimic mutant of Catharanthus roseus accumulates the opioid agonist, akuammicine.

Catharanthus roseus is a medicinal plant that produces an abundance of monoterpenoid indole alkaloids (MIAs), notably including the anticancer compounds vinblastine and vincristine. While the canonical pathway leading to these drugs has been resolved, the regulatory and catalytic mechanisms controlling many lateral branches of MIA biosynthesis remain largely unknown. Here, we describe an ethyl methanesulfonate (EMS) C. roseus mutant (M2-117523) that accumulates high levels of MIAs. The mutant exhibited stunted growth, partially chlorotic leaves, with deficiencies in chlorophyll biosynthesis, and a lesion-mimic phenotype. The lesions were sporadic and spontaneous, appearing after the first true bifoliate and continuing throughout development. The lesions are also the site of high concentrations of akuammicine, a minor constituent of wild type C. roseus leaves. In addition to akuammicine, the lesions were enriched in 25 other MIAs, resulting, in part, from a higher metabolic flux through the pathway. The unique metabolic shift was associated with significant upregulation of biosynthetic and regulatory genes involved in the MIA pathway, including the transcription factors WRKY1, CrMYC2, and ORCA2, and the biosynthetic genes STR, GO, and Redox1. Following the lesion-mimic mutant (LMM) phenotype, the accumulation of akuammicine is jasmonate (JA)-inducible, suggesting a role in plant defence response. Akuammicine is medicinally significant, as a weak opioid agonist, with a preference for the κ-opioid receptor, and a potential anti-diabetic. Further study of akuammicine biosynthesis and regulation can guide plant and heterologous engineering for medicinal uses.

Generating an EMS Mutant Population and Rapid Mutant Screening by Thin-Layer Chromatography Enables the Studies of Monoterpenoid Indole Alkaloids Biosynthesis in Catharanthus Roseus.

Decades of research on the medicinal plant Catharanthus roseus have led to the complete elucidation of the 29-step pathway for the biosynthesis of the anticancer drug vinblastine from geraniol and tryptophan precursors. Several approaches have been used to identify the enzymes involved in this iconic and remarkably complex pathway. This chapter describes the use of the classic ethyl methanesulfonate (EMS) mutagenesis to create a selfed M2 mutant population, which can be rapidly screened to select mutants with altered monoterpenoid indole alkaloid (MIA) biosynthesis with a simple, high-throughput thin-layer chromatography (TLC)-based screening strategy. This TLC-based MIA screening has led to the discovery and characterization of three enzymes responsible for vinblastine biosynthesis.

Molecular and biochemical characterization of Catharanthus roseus perivine-Nß-methyltransferase.

The biosynthesis of monoterpenoid indole alkaloids in Catharanthus roseus has been most extensively studied, leading to the detailed characterization of the pathway for the formation of their well-known anticancer alkaloids. The present study describes the identification, molecular cloning, and functional expression of C. roseus perivine-Nß-methyltransferase (PeNMT) that converts perivine to Nß-methylperivine (vobasine). PeNMT is member of a recently discovered γ-tocopherol-like N-methyltransferase (γ-TLMT) gene family that displays high substrate specificity and that appears to have evolved in the Vinceae tribe of Apocynaceae family where most N-methylated MIAs have been identified in the phytochemical literature.

A Catharanthus roseus Fe(II)/α-ketoglutarate-dependent dioxygenase catalyzes a redox-neutral reaction responsible for vindolinine biosynthesis.

The Madagascar's periwinkle is the model plant for studies of plant specialized metabolism and monoterpenoid indole alkaloids (MIAs), and an important source for the anticancer medicine vinblastine. The elucidation of entire 28-step biosynthesis of vinblastine allowed further investigations for the formation of other remarkably complex bioactive MIAs. In this study, we describe the discovery and characterization of vindolinine synthase, a Fe(II)/α-ketoglutarate-dependent (Fe/2OG) dioxygenase, that diverts assembly of tabersonine to vinblastine toward the formation of three alternatively cyclized MIAs: 19S-vindolinine, 19R-vindolinine, and venalstonine. Vindolinine synthase catalyzes a highly unusual, redox-neutral reaction to form a radical from dehydrosecodine, which is further cyclized by hydrolase 2 to form the three MIA isomers. We further show the biosynthesis of vindolinine epimers from tabersonine using hydrolase 2 catalyzed reverse cycloaddition. While the occurrence of vindolinines is rare in nature, the more widely found venalstonine derivatives are likely formed from similar redox-neutral reactions by homologous Fe/2OG dioxygenases.

Head-to-head comparison of various antipsychotic agents on genome-wide methylation in schizophrenia.

Aim: To explore possible differences in genome-wide methylation between schizophrenia patients who consume various antipsychotics. Methods: We compared DNA methylation in leukocytes between the following cohorts: clozapine (n = 19) versus risperidone (n = 19), clozapine (n = 12) versus olanzapine (n = 12), clozapine (n = 9) versus quetiapine (n = 9) and clozapine (n = 33) versus healthy controls (n = 33). Subjects were matched for age, sex, ethnicity, smoking status and leukocyte proportions. Results: No single CpG site reached genome-wide significance for clozapine versus risperidone/olanzapine/quetiapine. For clozapine versus quetiapine, one significantly differentially methylated region was found - ch5: 176797920-176798049 (fwer = 0.075). Clozapine versus healthy controls yielded thousands of significantly differentially methylated CpG sites. Conclusions: Establishing antipsychotic induced genome-wide methylation patterns will further elucidate the biological and clinical effects of antipsychotic administration.

Position Paper on Young Vascular Surgeons Training of the Mediterranean Federation for the Advancing of Vascular Surgery (MeFAVS): State of the Art and Perspectives.

The Mediterranean Federation for the Advancing of Vascular Surgery (MeFAVS) was founded in 2018, with the aim to promote cooperation among vascular professionals within Mediterranean countries. Due to its prominent social and economic impact on national health systems, diabetic peripheral artery was selected as the very first topic to be investigated by the federation. In this second paper, different experiences from delegates of participating countries were shared to define common strategies to harmonize, standardize, and optimize education and training in the Vascular Surgery specialty.

Glutathione Levels and Glutathione-Glutamate Correlation in Patients With Treatment-Resistant Schizophrenia.

Treatment-resistant schizophrenia (TRS) has been suggested to involve glutamatergic dysfunction. Glutathione (GSH), a dominant antioxidant, is known to be involved in glutamatergic neurotransmission. To date, no study has examined GSH levels in patients with TRS. The aim of this study was to examine GSH levels in the dorsal anterior cingulate cortex (dACC) of patients with TRS. Patients with schizophrenia were categorized into 3 groups with respect to their antipsychotic response: (1) clozapine (CLZ) nonresponders, (2) CLZ responders, and (3) first-line responders (FLR). GSH and glutamine + glutamate (Glx) levels were measured using 3T proton magnetic resonance spectroscopy. Firstly, dACC GSH levels were compared among the patient groups and healthy controls (HCs). Further, relationships between GSH and Glx levels were compared between the groups and GSH levels were explored stratifying the patient groups based on the glutamate-cysteine ligase catalytic (GCLC) subunit polymorphism. There was no difference in GSH levels between the groups. FLR showed a more negative relationship between GSH and Glx levels in the dACC compared to HCs. There were no effects of GCLC genotype on the GSH levels. However, CLZ responders had a higher ratio of high-risk GCLC genotype compared to CLZ nonresponders. This study demonstrated different relationships between GSH and Glx in the dACC between groups. In addition, the results suggest a potential link between CLZ response and GCLC genotype. However, it still remains unclear how these differences are related to the underlying pathophysiology of schizophrenia subtypes or the mechanisms of action of CLZ.

Rethinking palliative care in a public health context: addressing the needs of persons with non-communicable chronic diseases.

Non-communicable chronic diseases (NCCDs) are the main cause of morbidity and mortality globally. Demographic aging has resulted in older populations with more complex healthcare needs. This necessitates a multilevel rethinking of healthcare policies, health education and community support systems with digitalization of technologies playing a central role. The European Innovation Partnership on Active and Healthy Aging (A3) working group focuses on well-being for older adults, with an emphasis on quality of life and healthy aging. A subgroup of A3, including multidisciplinary stakeholders in health care across Europe, focuses on the palliative care (PC) model as a paradigm to be modified to meet the needs of older persons with NCCDs. This development paper delineates the key parameters we identified as critical in creating a public health model of PC directed to the needs of persons with NCCDs. This paradigm shift should affect horizontal components of public health models. Furthermore, our model includes vertical components often neglected, such as nutrition, resilience, well-being and leisure activities. The main enablers identified are information and communication technologies, education and training programs, communities of compassion, twinning activities, promoting research and increasing awareness amongst policymakers. We also identified key 'bottlenecks': inequity of access, insufficient research, inadequate development of advance care planning and a lack of co-creation of relevant technologies and shared decision-making. Rethinking PC within a public health context must focus on developing policies, training and technologies to enhance person-centered quality life for those with NCCD, while ensuring that they and those important to them experience death with dignity.

Genome-wide methylation association with current suicidal ideation in schizophrenia.

In this study, we investigate the epigenetic mechanisms associated with current suicidal ideation. Gene expression changes have been found in post-mortem brain of suicide victims. However, it is not clear how in-vivo gene expression change confers risk for suicide. DNA methylation is a form of epigenetic modification that regulates gene expression. Our primary aim is to investigate genome-wide methylation in conferring risk for current suicidal ideation (SI) in schizophrenia. The presence of current SI and genome-wide methylation patterns were assessed in 107 patients with schizophrenia. DNA methylation has been measured in white blood cells as a possible peripheral biomarker of SI. SI was the primary outcome variable in a model including methylation status of white blood cells using the Illumina 450 array. We have tested the association with genome-wide methylation levels in 19 subjects with current SI and 88 subjects without current SI and we found that higher methylation level in the CpG cg06121808 located in the gene SLC20A1 on chromosome 2 was associated with current SI (p = 0.000003; beta difference = 0.06). Furthermore, the distal promoter analysis showed that the gene SMPD2 was hypermethylated in suicide ideators (p = 0.0001; beta difference = 0.02). Thus, molecular biomarkers could advance our understanding of the molecular mechanisms of stress-related SI. Furthermore, the methylation sites that we have identified should be replicated in other suicide related phenotypes to generate robust biomarkers with high translational value for proof of concept interventions aiming at reducing SI.

Journey in the Polyphenol Research World with Ragai Ibrahim.

Dr. Ragai K. Ibrahim, Professor Emeritus at Concordia University, Montréal, Canada, passed away on the November 19, 2017 at the age of 88 years. Dr. Ibrahim dedicated his entire professional life to polyphenols and spent most of his academic career (1967-1997) at the Department of Biology of Concordia University in Montréal. He has been an active member of the Groupe Polyphénols since the beginning. This paper is a tribute to Dr. Ibrahim from some of his former students. An overview of the evolution of polyphenol research since the late 1950s and the outstanding contribution that Dr. Ibrahim had to this topic is given. The input of Dr. Ibrahim's research to the enzymology and genetics of polyphenol biosynthesis is discussed. Furthermore, the links between Dr. Ibrahim's work and some aspects of modern studies on the health benefits of polyphenols are presented.

The assembly of (+)-vincadifformine- and (-)-tabersonine-derived monoterpenoid indole alkaloids in Catharanthus roseus involves separate branch pathways.

The biological activity of monoterpenoid indole alkaloids (MIAs) has led to their use in cancer treatment and other medical applications. Their biosynthesis has involved the formation of reactive intermediates by responsible enzymes to elaborate several different chemical scaffolds. Modification of scaffolds through different substitution reactions has produced chemically diverse MIAs and related biological activities. The present study characterizes the three-step pathway involved in the formation of (+)-echitovenine, the major O-acetylated MIA of Catharanthus roseus roots, and differentiates it from a parallel pathway involved in the formation of hörhammericine. Separate hydrolases convert a common reactive MIA intermediate to aspidosperma skeletons of opposite specific rotations, that is (+)-vincadifformine and (-)-tabersonine, respectively. The formation of (+) minovincinine from (+) vincadifformine 19-hydroxylase (V19H) is catalyzed by a root-specific cytochrome P450 with high amino acid sequence similarity to the leaf-specific tabersonine-3-hydroxylase involved in vindoline biosynthesis. Similarly, O-acetylation of (+)-minovincinine to form (+) echitovenine involves minovincinine-O-acetytransferase. The substrate specificity of V19H and MAT for their respective (+)-enantiomers defines the separate enantiomer-specific pathway involved in (+)-echitovenine biosynthesis and differentiates it from a parallel (-)-enantiomer-specific pathway involved in the formation of hörhammericine from (-)-tabersonine.

Genetic study of neuregulin 1 and receptor tyrosine-protein kinase erbB-4 in tardive dyskinesia.

OBJECTIVES: Tardive dyskinesia (TD) is a movement disorder that may develop as a side effect of antipsychotic medication. The aetiology underlying TD is unclear, but a number of mechanisms have been proposed. METHODS: We investigated single-nucleotide polymorphisms (SNPs) in the genes coding for neuregulin-1 and erbB-4 receptor in our sample of 153 European schizophrenia patients for possible association with TD. RESULTS: We found the ERBB4 rs839523 CC genotype to be associated with risk for TD occurrence and increased severity as measured by the Abnormal Involuntary Movement Scale (AIMS) (P = .003). CONCLUSIONS: This study supports a role for the neuregulin signalling pathway in TD, although independent replications are warranted.

Completion of the canonical pathway for assembly of anticancer drugs vincristine/vinblastine in Catharanthus roseus.

The important anticancer drugs, vinblastine, vincristine and analogs, are composed of the monoterpenoid indole alkaloids (MIAs), catharanthine and vindoline, found uniquely in the medicinal plant, Catharanthus roseus. While 26 genes involved in the assembly of these two MIAs are known, two key reactions have eluded characterization to complete the documentation of the vinblastine pathway in this plant species. The assembly of these dimeric MIAs requires O-acetylstemmadenine oxidase (ASO) and a dual function geissoschizine synthase (GS) that reduces cathenamine to form geissoschizine, and that also reduces the ASO product to form a common intermediate for subsequent conversion by four separate hydrolases to catharanthine, tabersonine or vincadifformine, respectively. The in planta role of ASO is supported by identifying a single amino acid-substituted ASO mutant with very low enzyme activity and by virus-induced gene silencing of ASO to produce plants that accumulate O-acetylstemmadenine rather than catharanthine and vindoline found in wild-type (WT) plants. The in planta role of GS is supported by showing that a low GS-expressing mutant accumulating lower levels of catharanthine and vindoline also displays significantly lower tabersonine-forming activity in coupled enzyme assays than in the WT background. Gene expression analyses demonstrate that both ASO and GS are highly enriched in the leaf epidermis where the pathways for catharanthine and tabersonine biosynthesis are expressed. The full elucidation of this canonical pathway enables synthetic biology approaches for manufacturing a broad range of MIAs, including these dimers used in cancer treatment.

Frailty as the Future Core Business of Public Health: Report of the Activities of the A3 Action Group of the European Innovation Partnership on Active and Healthy Ageing (EIP on AHA).

Background: The prevalence of frailty at population-level is expected to increase in Europe, changing the focus of Public Health. Here, we report on the activities of the A3 Action Group, focusing on managing frailty and supporting healthy ageing at community level. Methods: A three-phased search strategy was used to select papers published between January 2016 and May 2018. In the third phase, the first manuscript draft was sent to all A3-Action Group members who were invited to suggest additional contributions to be included in the narrative review process. Results: A total of 56 papers were included in this report. The A3 Action Group developed three multidimensional tools predicting short⁻medium term adverse outcomes. Multiple factors were highlighted by the group as useful for healthcare planning: malnutrition, polypharmacy, impairment of physical function and social isolation were targeted to mitigate frailty and its consequences. Studies focused on the management of frailty highlighted that tailored interventions can improve physical performance and reduce adverse outcomes. Conclusions: This review shows the importance of taking a multifaceted approach when addressing frailty at community level. From a Public Health perspective, it is vital to identify factors that contribute to successful health and social care interventions and to the health systems sustainability.

Solution of the multistep pathway for assembly of corynanthean, strychnos, iboga, and aspidosperma monoterpenoid indole alkaloids from 19E-geissoschizine.

Monoterpenoid indole alkaloids (MIAs) possess a diversity of alkaloid skeletons whose biosynthesis is poorly understood. A bioinformatic search of candidate genes, combined with their virus-induced gene silencing, targeted MIA profiling and in vitro/in vivo pathway reconstitution identified and functionally characterized six genes as well as a seventh enzyme reaction required for the conversion of 19E-geissoschizine to tabersonine and catharanthine. The involvement of pathway intermediates in the formation of four MIA skeletons is described, and the role of stemmadenine-O-acetylation in providing necessary reactive substrates for the formation of iboga and aspidosperma MIAs is described. The results enable the assembly of complex dimeric MIAs used in cancer chemotherapy and open the way to production of many other biologically active MIAs that are not easily available from nature.

A tabersonine 3-reductase Catharanthus roseus mutant accumulates vindoline pathway intermediates.

MAIN CONCLUSION: Monoterpenoid indole alkaloids (MIAs) have remarkable biological properties that have led to their medical uses for a variety of human diseases. Mutagenesis has been used to generate plants with new alkaloid profiles and a useful screen for rapid comparison of MIA profiles is described. The MIA mutants identified are useful for investigating MIA biosynthesis and for targeted production of these specialised metabolites. The Madagascar periwinkle (Catharanthus roseus) is the sole source of the dimeric anticancer monoterpenoid indole alkaloids (MIAs), 3',4'-anhydrovinblastine and derivatives, which are formed via the coupling of the MIAs, catharanthine and vindoline. While intense efforts to identify parts of the complex pathways involved in the assembly of these dimers have been successful, our understanding of MIA biochemistry in C. roseus remains limited. A simple thin layer chromatography screen of 4000 ethyl methanesulfonate-metagenized M2 plants is described to identify mutant lines with altered MIA profiles. One mutant (M2-1865) accumulated reduced levels of vindoline inside the leaves in favour of high levels of tabersonine-2,3-epoxide and 16-methoxytabersonine-2,3-epoxide on the leaf surface. This MIA profile suggested that changes in tabersonine 3-reductase (T3R) activity might be responsible for the observed phenotype. Molecular cloning of mutant and wild type T3R revealed two nucleotide substitutions at cytosine residues 565 (CAT to TAT) and 903 (ACC to ACA) in the mutant corresponding to substitution (H189Y) and silent (T305T) amino acid mutations, respectively, in the protein. The single amino acid substitution in the mutant T3R protein diminished the biochemical activity of T3R by 95% that explained the reason for the low vindoline phenotype of the mutant. This phenotype was recessive and exhibited standard Mendelian single-gene inheritance. The stable formation and accumulation of epoxides in the M2-1865 mutant provides a dependable biological source of these two MIAs.

Geissoschizine synthase controls flux in the formation of monoterpenoid indole alkaloids in a Catharanthus roseus mutant.

MAIN CONCLUSION: A Catharanthus roseus mutant accumulates high levels of ajmalicine at the expense of catharanthine and vindoline. The altered chemistry depends on increased expression and biochemical activities of strictosidine ß-glucosidase and ajmalicine synthase activities and reduced expression and biochemical activity of geissoschizine synthase. The Madagascar periwinkle [Catharanthus roseus (L.) G. Don] is a commercially important horticultural flower species and is a valuable source for several monoterpenoid indole alkaloids (MIAs), such as the powerful antihypertensive drug ajmalicine and the antineoplastic agents, vinblastine and vincristine. While biosynthesis of the common MIA precursor strictosidine and its reactive aglycones has been elucidated, the branch point steps leading to the formation of different classes of MIAs remain poorly characterized. Screening of 3600 ethyl methyl sulfonate mutagenized C. roseus plants using a simple thin-layer chromatography screen yielded a mutant (M2-0754) accumulating high levels of ajmalicine together with significantly lower levels of catharanthine and vindoline. Comparative bioinformatic analyses, virus-induced gene silencing, and biochemical characterization identified geissoschizine synthase, the gateway enzyme that controls flux for the formation of iboga and aspidosperma MIAs. The reduction of geissoschizine synthase transcripts in this high ajmalicine mutant, together with increased transcripts and enzyme activities of strictosidine ß-glucosidase and of heteroyohimbine synthase, explains the preferential formation of ajmalicine in the mutant instead of catharanthine and vindoline that accumulates in the wild-type parent. Reciprocal crosses established that that the high ajmalicine phenotype is inherited as a Mendelian recessive trait.