Page 243 - Plant Canada 2024 Proceeding

PLANT CANADA 2024

[P79] CHARACTERIZING THE CULM SKIN PIGMENTS OF BLACK BAMBOO: INTERGRATING
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TRADITIONAL AND MODERN METHODOLOGIES. Xinyi Huang , Xinchun Lin , and Shawn D.
Mansfield . Department of Botany, University of British Columbia, 6270 University Boulevard, Vancouver,
1 1
2
BC, Canada V6T1Z4; and State Key Laboratory of Subtropical Silviculture, Zhejiang Agriculture and
Forestry University, Hangzhou, Zhejiang Province, China
Correspondence to: xinyi.huang@ubc.ca; shawn.mansfield@ubc.ca

Bamboo (Bambusoideae) is one of the most important non-timber forest products globally. With over
1400 species natively distributed across every continent except Europe and Antarctica, bamboo exhibits
a high degree of morphological and genetic diversity. It is also the fastest growing grass, providing
versatile resources as a promising answer to escalating concerns of climate change, food security, and
energy demands. With its significant agricultural, economical, and cultural values, around 2.5 billion
people cultivate and consume bamboo daily, generating an international trade reaching nearly $70 billion
US per annum.

There is a great variation among bamboo species when it comes to the colour and pattern of their culms.
In addition to most common green colouration, bamboo culms can also be light gray, yellow, cyan, and
black, with or without stripes or spots of a secondary colour. For many species, culm colours can change
depends on factors such as life stages and environmental conditions. Identifying these pigments and
elucidating their biosynthetic pathways are not only important because of the cultural and aesthetic values
of these bamboos, but also significant for taxonomical and evolutionary studies. Recent analyses suggest
that the metabolites responsible for bamboo culm colour variations are most likely to be flavonoids, which
could exhibit beneficial antioxidant properties, offering added values to downstream applications.
Phyllostachys nigra, commonly known as black or purple bamboo, is a commercially available bamboo
species native to China. It has been successfully imported and adapted to North America geography, and
has been consistently grown in gardens and for industrial purposes. Its culms emerge green when young,
but slowly accumulate purplish pigments first as dark purple spots, and then eventually become
completely black across the whole culm. In this study, we aimed to identify the secondary metabolites
responsible for this unique colour by analyzing the culm skin tissue of two bamboo varieties,
Phyllostachys nigra nigra and Phyllostachys nigra henonis, grown at the Botanical Garden of the
University of British Columbia. Traditional techniques such as UV-Vis spectroscopy and thin layer
chromatography were employed to characterize the extracted pigments, in addition to untargeted
metabolomic profiling via HPLC-QToF-MS/MS to compare young green tissue versus mature black
tissue. Total chlorophyll and carotenoid contents were also quantified. These biochemical analyses will be
coupled with transcriptomic sequencing to aid in the exploration of associated genes and pathways.

[P80] PURIFICATION AND DIFFERENTIATION OF YOHIMBINE AND ITS ISOMERS FROM YOHIMBE
TREE BARK. Jaewook Hwang. University of New Brunswick
Correspondence to: jhwang1@unb.ca

Specialized metabolites, organic compounds produced by plants and other organisms, are highly valued
in pharmacology and agriculture for their wide-ranging bioactive properties, finding applications in
medicines, fragrances, flavorings, and pesticides. Among the specialized metabolites, Monoterpenoid
Indole Alkaloids (MIAs) stand out as a significant class, notably abundant in plants from the Rubiaceae,
Apocynaceae, and Loganiaceae families, from which numerous pharmaceuticals have been derived. The
yohimbe tree, Pausinystalia johimbe apart of the Rubiaceae family, native to Western and Central Africa,
is of particular interest due to its main active compound, yohimbine, traditionally used as an aphrodisiac
and now prescribed for erectile dysfunction. Yohimbine is characterized by its complex molecular
structure, including five chiral centers that lead to the formation of multiple stable isomers, such as
rauwolscine, beta-yohimbine, corynanthine, and alo-yohimbine. Direct extraction from yohimbe bark was
conducted for authentic analysis. Employing advanced techniques like thin-layer chromatography, high-
performance liquid chromatography, mass spectrometry, nuclear magnetic resonance spectrometry, and
polarimetry. The application of these methods not only ensures the accurate identification of the target
compounds but also facilitates a deeper understanding of their structural intricacies. This research not
only clarifies the compound profiles of yohimbine and its isomers but also lays the groundwork for
exploring the enzymatic pathways involved in MIA biosynthesis, offering new perspectives for drug
development and therapeutic innovations.

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