Monitoring Indian "Superfood" Moringa oleifera Lam. - species-specific PCR-fingerprint-based authentication for more consumer safety.

Moringa oleifera Lam. has become one of the major new superfoods commonly available in the aisles of bio-shops and health-food sections in supermarkets of North America and Europe. While most of these products appear under the generic and scientifically inconclusive term "Moringa", the European Union, so far, has allowed commercialisation for the use in food and feed for M. oleifera only. M. oleifera is indigenous to India and South Asia, but large-scale cultivation of this species has spread to the tropical regions on all continents, with a strong focus on Africa, leading to a high risk of admixture with species like M. stenopetala (Baker f.) Cufod. that is native to Africa. In the present study, we have characterised six species of Moringa in order to develop a simple and robust authentication method for commercial products. While the plants can be discriminated based on the pinnation of the leaves, this does not work for processed samples. As alternative, we use the plastidic markers psbA-trnH igs and ycf1b to discern different species of Moringa and develop a diagnostic duplex-PCR that clearly differentiates M. oleifera from other Moringa species. This DNA-based diagnostic assay that does not rely on sequencing was validated with commercial products of "Moringa" (including teas, powders, or capsules). Our method provides a robust assay to detect adulterations, which are economically profitable for costly superfood products such as "Moringa".

DNA barcoding as new diagnostic tool to lethal plant poisoning in herbivorous mammals.

Reliable identification of plant species in the digestive tract of a deceased animal often represents the major key to diagnose a lethal intoxication with poisonous plants in veterinary pathology. In many cases, identification of the species is challenging or even impossible because the diagnostic morphological features have been degraded, and because the interpretation of such features requires a considerable expertise in plant anatomy and biodiversity. The use of DNA barcoding markers can support or even replace classical morphological assessment. While these markers have been widely used for plant taxonomy, their forensic application to clarify causes of animal poisoning is novel. In addition, we use specific single-nucleotide polymorphisms as fingerprints. This allows for a clear decision even in cases, where the conventionally used statistical e-values remain ambiguous. In the current work, we explore the feasibility of this strategy in a couple of exemplary cases, either in concert with anatomical diagnostics, or in cases where visual species identification is not possible, or where chemical toxin detection methods are not well established, complex, time consuming and expensive.

Cellular Base of Mint Allelopathy: Menthone Affects Plant Microtubules.

Plants can use volatiles for remote suppression of competitors. Mints produce essential oils, which are known to affect the growth of other plants. We used a comparative approach to identify allelopathic compounds from different Mints (genus Mentha, but also including Cat Mint, Nepeta cataria, and Corean Mint, Agastache rugosa, belonging to sisters clades within the Mentheae) using the standard cress germination assay as readout. To understand the mechanism behind this allelopathic effect, we investigated the response of tobacco BY-2 cell lines, expressing GFP-tagged markers for microtubules and actin filaments to these essential oils. Based on the comparison between bioactivity and chemical components, we identified menthone as prime candidate for the allelopathic effect, and confirmed this bioactivity targeted to microtubules experimentally in both, plant cells (tobaccoBY-2), and seedlings (Arabidopsis thaliana). We could show that menthone disrupted microtubules and induced mortality linked with a rapid permeabilization (less than 15 min) of the plasma membrane. This mortality was elevated in a tubulin marker line, where microtubules are mildly stabilized. Our study paves the way for the development of novel bioherbicides that would be environmentally friendly.

Goji Who? Morphological and DNA Based Authentication of a "Superfood".

"Goji" (Lycium barbarum and Lycium chinense) is a generic name for medical plants with a long historical background in the traditional Chinese medicine. With the emerging trend of "Superfoods" several years ago, Goji berries soon became an established product in European countries and not only are the most popular product of traditional Chinese medicine outside of China but to this day one of the symbols of the entire "Superfood" trend. However, since Goji is an umbrella term for different plant species that are closely related, mislabeling and adulterations (unconsciously or purposely) are possible. We carefully verified the identity of Goji reference plant material based on morphological traits, mainly floral structures of several inflorescences of each individual, in order to create a robust background for the downstream applications that were used on those reference plants and additionally on commercial Goji products. We report morphological and molecular based strategies for the differentiation of Lycium barbarum and Lycium chinense. The two different Goji species vary significantly in seed size, with an almost double average seed area in Lycium chinense compared to Lycium barbarum. Differences could be traced on the molecular level as well; using the psbA-trnH barcoding marker, we detected a single nucleotide substitution that was used to develop an easy one-step differentiation tool based on ARMS (amplification refractory mutation system). Two diagnostic primers used in distinct multiplex PCRs yield a second diagnostic band in a subsequent gel electrophoresis for Lycium barbarum or Lycium chinense, respectively. Our ARMS approach is a strong but simple tool to trace either of the two different Goji species. Both the morphological and the molecular analysis showed that all of the tested commercial Goji products contained fruits of the species Lycium barbarum var. barbarum, leading to the assumption that consumer protection is satisfactory.