Speakers

Biography

Manu Khajuria has earned her Ph.D. in Botany, specializing in plant adaptive biology. Since 2014, her research has been dedicated to understanding the adaptive potential of high-altitudinal plants in the Ladakh Himalayan region. Furthermore, her studies explore the correlation between photochemical efficiency and Δ⁹ – tetrahydrocannabinol content in Cannabis sativa L., presenting a novel investigation within plant biology. Currently positioned as a Scientist in the Plant Sciences and Agrotechnology Division at CSIR-Indian Institute of Integrative Medicine in Jammu, India, she continues to advance scientific knowledge in the intricate field of plant adaptation. Her work is a valuable contribution to the broader scientific community, shedding light on the intricate interplay between environmental factors and plant physiology in challenging ecosystems.

Abstract

Cannabis sativa L. is a multifaceted botanical resource, encompassing robust fibers, nutritious seeds, and medically relevant phytocannabinoids such as tetrahydrocannabinol (THC) and cannabidiol (CBD). Light, a critical environmental factor, has been recognized as a pivotal modulator influencing biomass and cannabinoid yield, acting through a responsive photochemical apparatus. This study aims to elucidate the intricate relationship between escalating metabolic THC levels and photochemical efficiency in Cannabis. The investigation involved comprehensive analyses encompassing chlorophyll fluorescence kinetics, photosynthetic pigments, and immune-detection of photosynthetic machinery across seven Cannabis accessions originating from diverse environments. Concurrently, cannabinoid content assessment facilitated the categorization of accessions into three distinct groups based on their relative CBD and THC content. Our findings reveal a stoichiometrically negative correlation between THC content and key photochemical performance indicators, as assessed through OJIP kinetics. Notably, Zeaxanthin-dependent quenching emerged as a predominant contributor to reduced Non-Photochemical Quenching (NPQ) in Group III, characterized by elevated THC content (THC > 6%). Further validation through THC treatment in Arabidopsis thaliana corroborated a dose-dependent decline in photochemical efficiency, underscoring the exclusive role of THC in eliciting this response. Concurrently, the observed phenomenon damaged essential photosynthetic proteins, including D1, RbCL, and Lhc1 protein holo-complex, compromising overall plant health and yield. Furthermore, the study introduces a novel screening method for Cannabis based on cannabinoid content, offering practical insights into the intricate interplay between THC, photochemical efficiency, and the holistic health of the plant. These findings contribute to the broader understanding of Cannabis physiology and cultivation practices for optimized biomass and cannabinoid production.

Keywords: Cannabidiol, Cannabis sativa, Photochemical efficiency, Non-photochemical quenching, OJIP Kinetics