科学家对大麻植物的毛状体(或“细胞工厂”)进行了极其详细的研究，揭示出蘑菇状毛发的花在气味和大麻素含量方面最为有效。
“毛状体是大麻植物的生化工厂，这项研究是理解它们如何制造和储存有价值的产品的基础，”合著者之一、不列颠哥伦比亚大学(UBC)博士后蒂根·基里奇尼在1997年说声明。
含有“霜状”毛状体的芬诺拉花。
大麻植物的有价值的产品是其代谢物(即大麻素和萜烯)，这些物质在雌花的腺毛中大量产生——也就是“大麻芽”。这些腺毛有三种形态——球状、无柄和柄。然而，直到现在，人们对这些不同的形状如何影响工厂的化学产出还知之甚少。
为了找到答案，研究人员开发了一种涉及双光子显微镜和固有自发荧光模式的技术。这使得他们能够研究一种叫做芬欧拉的大麻变种中不同毛状体的内部结构。
结果现已发表在植物杂志。
柄腺毛的多光子显微图像。
结果是，在紫外光下，茎状毛具有蓝色自发荧光，反映了植物较高的大麻素水平。相反，无柄毛状体具有红色自发荧光，表明代谢物水平较低。
这项技术还揭示了茎毛状体包含12到16个分泌盘细胞簇。无柄毛状体中的毛状体越来越小，数量越来越少(8)，而球状毛状体中的毛状体则难以区分，因此不能包括在分析中。
UBC植物学博士候选人、合著者萨姆·利文斯顿说:“我们看到被跟踪的腺毛已经扩大了“细胞工厂”，以制造更多大麻素和芳香萜烯。”。
“我们还发现它们从固着样前体生长出来，在发育过程中经历了戏剧性的转变，这可以用新的显微镜工具观察到。”
腺毛的多光子显微图像
通过观察不同毛状体的脱氧核糖核酸，研究人员能够证实大麻素生产中的大多数基因都存在于所有三种毛状体中。研究人员说，那些被跟踪的滴虫似乎特别倾向于制造大麻二酚酸(CBDA)——这一发现可能会对大麻行业的人产生实际影响，大麻行业已经超过了九个州的国内生产总值，商业内幕报道。
安妮·莱西·萨缪尔斯是UBC大学的首席研究员和植物学教授，她描述了一个与大麻素和萜烯生产相关的“基因宝库”，大麻素和萜烯可以被调整以促进“理想的特性”
萨缪尔斯说:“通过进一步的研究，这可以利用分子遗传学和常规育种技术来产生理想的性状，如更高产的大麻品系或具有特定大麻素和萜烯特征的品系。”。
柄毛(左)、无柄毛(中)和腺毛(右)。
接下来的步骤将包括找出毛状体是如何“导出和存储”代谢物。利文斯顿说，这特别有趣，因为大麻植物中的代谢物水平应该对细胞有毒。“我们想知道他们是如何做到这一点的。”
“尽管大麻具有很高的经济价值，但由于法律限制，我们对大麻植物生物学的理解仍处于初级阶段，”奇利钦尼补充道。
MICROSCOPIC IMAGES REVEAL THE MOST POTENT CANNABIS FLOWERS IN INCREDIBLE DETAIL
Scientists have studied the trichomes (or "cellular factories") of the cannabis plant in extreme detail, revealing that flowers with mushroom-shaped hairs are the most potent—both in terms of smell and cannabinoid content.
"Trichomes are the biochemical factories of the cannabis plant and this study is the foundation for understanding how they make and store their valuable products," co-lead author Teagen Quilichini, a postdoctoral fellow at the University of British Columbia (UBC), said in a statement.
Finola flower containing "frost-like" trichomes.
The valuable products of the cannabis plants are its metabolites (i.e. the cannabinoids and terpenes), which are amply produced in the glandular trichomes of the female flower—aka the "marijuana bud." These glandular trichomes come in three variations defined by their appearance—bulbous, sessile and stalked. However, until now, little was understood about how these different shapes affected the plant's chemical outputs.
To find out, the researchers developed a technique involving two-photon microscopy and intrinsic autofluorescence patterns. This allowed them to study the internal structures of different trichomes in a hemp variant called Finola.
The results have now been published in The Plant Journal.
Multiphoton microscopy image of stalked glandular trichome.
The result was that under ultraviolet light, the stalked trichomes possessed blue autofluorescence, reflecting the plant's higher cannabinoid levels. Conversely, the sessile trichomes possessed a red autofluorescence, signaling lower levels of the metabolite.
The technique also revealed the stalked trichomes contained clusters of 12 to 16 secretory disc cells. Those in the sessile trichomes were smaller and fewer in number (8), while those in the bulbous trichomes were indistinguishable and, as such, could not be included in the analysis.
"We saw that stalked glandular trichomes have expanded "cellular factories" to make more cannabinoids and fragrant terpenes," said co-lead author Sam Livingston, a Ph.D. candidate at UBC botany.
"We also found that they grow from sessile-like precursors and undergo a dramatic shift during development that can be visualized using new microscopy tools."
Multiphoton microscopy image of glandular trichomes
By looking at the DNA of the different trichomes, the researchers were able to confirm that the majority of genes involved in cannabinoid production are found in all three trichome types. Those in the stalked trichomes, the researchers say, appear to be particularly geared towards making cannabidiolic acid (CBDA)—a discovery that could have practical implications for those in the marijuana business, an industry already worth more than the GDP of nine states, Business Insider reported.
Anne Lacey Samuels, the principal investigator and a botany professor at UBC, described a "treasure trove of genes" related to the production of cannabinoids and terpenes, which could be tweaked to promote "desirable traits."
"With further investigation, this could be used to produce desirable traits like more productive marijuana strains or strains with specific cannabinoid and terpene profiles using molecular genetics and conventional breeding techniques," said Samuels.
Stalked (left), sessile (center) and glandular (right) trichomes.
The next steps will involve finding out how the trichomes "export and store" metabolites. This is particularly intriguing as levels of metabolites in cannabis plants should be toxic to the cells, says Livingston. "We want to understand how they manage this."
"Despite its high economic value, our understanding of the biology of the cannabis plant is still in its infancy due to restricted legal access," Quilichini added.
