Recent Advances in Research on Cannabis sativa L. Endophytes and Their Prospect for the Pharmaceutical Industry

Abstract

Endophytic microorganisms residing within plants are constantly communicating with them and the external environment by means of various interaction mechanisms and biochemical processes. Although plants have evolved their own defense mechanisms, sometimes they fail to defend themselves from the constant attack of devastating and emerging pathogens. Thus, research involving endophytes that aid the defense responses of their host plants can be useful in biocontrol and pest management strategies. Elucidating the chemistry of endophyte-plant interactions can provide new insights into the production of target and/or nontarget metabolites, thereby enabling a better understanding of the metabolic processes in planta and ex planta. In this chapter, we highlight the interactions of endophytes harbored in the medicinally important plant Cannabis sativa L. with the host plant as well as with the pathogens. The various endophyte-plant-pathogen defense-counter defense crosstalk would aid in exploring the biocontrol potential of endophytes in thwarting pathogens attacking the plants, and thus, effectively decrease the loss of such therapeutically relevant medicinal plants. Such interactions will further lead to the discovery of bioactive compounds, including the ones exclusive to the host plants. This chapter deals with the recent advances made

Molecular Identification of Endophytic Fungi and Their Pathogenicity Evaluation Against Dendrobium nobile and Dendrobium officinale

“…This stage is only a transitory time where environmental influences play a key role in destabilizing the delicate equilibrium of antagonisms. [18]. Endophytic fungi can deliver appropriate carbon sources, amino acids, vitamins, and hormones that are important for seedling and protocorm development [19].…”

“…Plant-pathogen association may be responsible for the growth conditions for plant disease. Because several fungal endophytes may be latent plant pathogens, certain inherent or environmental influences may prompt pathogenic effects [18]. Many fungal endophytes are silent/conditional pathogens, only resulting in disease as the plant ages or under stress conditions.…”

Emerging diseases of Cannabis sativa and sustainable management

“…A diverse group of fungal and bacterial species were identified in hemp and cannabis plants by direct plating methods and molecular analyses. 35 , 44 While many of them were proposed to benefit the plant, 44 , 45 , 53 , 54 , 55 establishing effects on the growth of cannabis plants requires rigorous experimentation, similar to that required for proof of pathogenicity of presumed pathogens. Proposed beneficial roles of endophytes in cannabis and hemp plants that appear in the literature, therefore, should be interpreted cautiously until evidence has been obtained through experimentation.…”

“…Proposed beneficial roles of endophytes in cannabis and hemp plants that appear in the literature, therefore, should be interpreted cautiously until evidence has been obtained through experimentation. For example, there is no evidence to suggest that endophytes can alter the secondary metabolism and cannabinoid profiles in cannabis 45 , 55 or provide protection against pathogens. 53 , 54 The metabolic pathways and genes that lead to cannabinoid production are complex 1 , 3 , 56 , 57 and evidence of transcriptional or translational regulation by endophytes is lacking.…”

Importance of Molecular Data to Identify Fungal Plant Pathogens and Guidelines for Pathogenicity Testing Based on Koch’s Postulates

“…This is because several organisms are present as endophytes or epiphytes on plant surface and do not cause disease; therefore, it is vital to confirm that the isolate is responsible for the pathogenicity [ 18 ]. Endophytes can become latent plant pathogens under certain inherent or environmental conditions or they can be conditional pathogens, which causes diseases as the plant ages or under stress conditions [ 19 ]. If the fungus is sporulating on the leaf lesion, it is relatively easy to identify the species to genus via its morphology [ 20 , 21 , 22 , 23 , 24 ], and obtain an isolate of the taxon via single spore isolation [ 25 ].…”