Maximum Yield USA 2015 April | Page 116

Survive avant-gardening Striving to Essential Oils, Glandular Trichomes & the Secondary Metabolism by Kyle L. Ladenburger Have you ever wondered why plants produce those amazing compounds that essential oils are derived from? It all has to do with glandular trichomes—tiny, specialized, hair-like formations found on plant stems and leaves. Kyle L. Ladenburger explains what glandular trichomes are, why certain plants developed them, and how to enhance the production of them in your plants at home. T he essential oil industry is a billion-dollar-a-year business that doesn’t show any signs of slowing down. Essential oils derived from plants, including mint, basil and thyme, are key ingredients in products such as medicines, aromatic fragrances and flavorings. Demand for these products has been the driving force behind countless research studies conducted with the goal of understanding how and why plants produce these Secondary unique chemical compounds, and how growers can metabolite enhance the production compounds are of these compounds. The believed to play research begins with the glandular trichome. “ a major role in a plant’s ability to adapt to the dangers of their environment.” Glandular Trichomes Glandular trichomes are tiny, specialized, hair-like formations found on the epidermis of plant stems and leaves. At the tip of the hairs are glandular cells that produce, store and eventually secrete exudates such as essential oils. Nearly all plant species produce some sort of 114 Maximum Yield USA  |  April 2015 hair-like formation, but only about 30% of vascular plants have the ability to create these sought-after substances. Glandular trichomes come in several different shapes that are highly species-specific, to the point where they are often a characteristic used in the classification and identification of a plant species. The different types of glandular trichome exudates include terpenoids, phenylpropenes, flavonoids and methyl ketones. To understand what these unique chemical compounds are, we must first address why they are produced. The Secondary Metabolism Glandular trichomes are not directly connected to a plant’s vascular system and therefore are not products of a plant’s primary metabolism. Primary metabolites—products of