Metabolomic Profiling of the Desiccation-Tolerant Medicinal Shrub Myrothamnus flabellifolia Indicates Phenolic Variability Across Its Natural Habitat: Implications for Tea and Cosmetics Production

Abstract

The leaves and twigs of the desiccation-tolerant medicinal shrub Myrothamnus flabellifolia are harvested for use in traditional and commercial teas and cosmetics due to their phenolic properties. The antioxidant and pharmacological value of this plant has been widely confirmed; however, previous studies typically based their findings on material collected from a single region. The existence of phenolic variability between plants from different geographical regions experiencing different rainfall regimes has thus not been sufficiently evaluated. Furthermore, the anthocyanins present in this plant have not been assessed. The present study thus used an untargeted liquid chromatography-tandem-mass spectrometry approach to profile phenolics in M. flabellifolia material collected from three climatically distinct (high, moderate, and low rainfall) regions representing the western, southern, and eastern extent of the species range in southern Africa. Forty-one putative phenolic compounds, primarily flavonoids, were detected, nine of which are anthocyanins. Several of these compounds are previously unknown from M. flabellifolia. Using multivariate statistics, samples from different regions could be distinguished by their phenolic profiles, supporting the existence of regional phenolic variability. This study indicates that significant phenolic variability exists across the range of M. flabellifolia, which should inform both commercial and traditional cultivation and harvesting strategies.

Unravelling the Antibacterial Activity of Terminalia sericea Root Bark through a Metabolomic Approach

“…Its 1 H and 13 C NMR spectra ( Figure S8A & B) were identical to those in literature [ 42 ]. Also, the fragmentation ions ( m/z 599, 447, 300) ( Figure S8C ) obtained from the UPLC-MS/MS [M − H] − were in agreement with the structure and literature data [ 43 ].…”

Angiosperms at the edge: Extremity, diversity, and phylogeny

“…Geophytism is most prevalent in more seasonal, cold, and arid habitats, and was traditionally thought to be particularly associated with seasonal semi-arid biomes. In contrast to these traditional ideas, recent global datasets indicate that cold tolerance may be the stronger correlate (Howard et al, 2019 Myrothamnus and some species of Gunnera L. tolerant of mild freezing (Bentley, Moore, & Farrant, 2019;Moore, Lindsey, Farrant, & Brandt, 2007;Skeffington & Hall, 2011). Myrothamnus, while one of several angiosperm lineages to independently gain the "resurrection plant" habit (that is, tolerance of extreme tissue desiccation), is by far the most phylogenetically isolated, and the only example with a woody habit (Moore et al, 2007).…”

Unexplored dimensions of variability in vegetative desiccation tolerance

“…Screening natural populations to identify exceptionally tolerant ecotypes and mining the genetic variability contained within is a promising approach for identifying key genes for desiccation tolerance (Kovach and McCouch, 2008; Zamir, 2008). Many desiccation‐tolerant angiosperms are widely distributed across central and southern Africa, Asia, Australia, or South America with stark differences in elevation, precipitation, and temperature across their native range (Bentley et al, 2019; Porembski and Barthlott, 2000). For example, annual precipitation across the distribution of Myrothamnus flabellifolia ranges from <250 mm in Namibia to >1000 mm in Malawi (Bentley et al, 2019).…”

“…Many desiccation‐tolerant angiosperms are widely distributed across central and southern Africa, Asia, Australia, or South America with stark differences in elevation, precipitation, and temperature across their native range (Bentley et al, 2019; Porembski and Barthlott, 2000). For example, annual precipitation across the distribution of Myrothamnus flabellifolia ranges from <250 mm in Namibia to >1000 mm in Malawi (Bentley et al, 2019). Other resurrection plants occur across similar geographical ranges, and it is possible that levels of desiccation tolerance vary in concordance.…”