An Update on Plant Photobiology and Implications for Cannabis Production

Abstract

This review presents recent developments in plant photobiology and lighting systems for horticultural crops, as well as potential applications for cannabis ( Cannabis sativa and C. indica ) plant production. The legal and commercial production of the cannabis plant is a relatively new, rapidly growing, and highly profitable industry in Europe and North America. However, more knowledge transfer from plant studies and horticultural communities to commercial cannabis plant growers is needed. Plant photosynthesis and photomorphogenesis are influenced by light wavelength, intensity, and photoperiod via plant photoreceptors that sense light and control plant growth. Further, light properties play a critical role in plant vegetative growth and reproductive (flowering) developmental stages, as well as in biomass, secondary metabolite synthesis, and accumulation. Advantages and disadvantages of widespread greenhouse lighting systems that use high pressure sodium lamps or light emitting diode (LED) lighting are known. Some artificial plant lighting practices will require improvements for cannabis production. By manipulating LED light spectra and stimulating specific plant photoreceptors, it may be possible to minimize operation costs while maximizing cannabis biomass and cannabinoid yield, including tetrahydrocannabinol (or Δ 9 -tetrahydrocannabinol) and cannabidiol for medicinal and recreational purposes. The basics of plant photobiology (photosynthesis and photomorphogenesis) and electrical lighting systems are discussed, with an emphasis on how the light spectrum and lighting strategies could influence cannabis production and secondary compound accumulation.

Scientific Prospects for Cannabis-Microbiome Research to Ensure Quality and Safety of Products

“…Characterization, prevention, and control of Cannabis pathogens, including pre-and post-harvest molds and their mycotoxins, will represent a major challenge for Cannabis science and safe product production. Preventive research on the photobiology of indoor production [88] can address common pathobiology problems across Cannabis growth stages under LED and HPS lighting systems. Associated meta-analyses [89] can further predict Cannabis yield or determine the mycotoxin profile in diseased plants under light stress.…”

Influence of Electromagnetic Stimulation of Seeds on the Photosynthetic Indicators in Medicago sativa L. Leaves at Various Stages of Development

“…Light-dependent photosynthesis reactions take place in the thylakoid membranes, and light-independent reactions in the stroma. Literature reports suggest that the light-dependent phase takes place in two photosystems (i.e., photosystem I-PSI and photosystem II-PSII) [6]. Photosynthetic pigments include chlorophylls and carotenoids which are located in thylakoid membranes.…”

“…Photosynthetic pigments include chlorophylls and carotenoids which are located in thylakoid membranes. PAR (photosynthetically active radiation 400-700 nm) sunlight is absorbed in antenna complexes by molecular chlorophyll and carotenoids [6][7][8], which is why light plays such an important role in the growth and development of plants. Its deficit results in slower growth as well as lower chlorophyll content in leaves.…”

“…Measurements of chlorophyll a fluorescence allow one to determine the condition of the photosynthetic apparatus and overall physiological condition of higher plants [9]. For this purpose, different types of fluorometers can be used which are fairly easy to operate and provide a fast and noninvasive measurement [6]. Chlorophyll a absorbs light at approximately 650-670 nm, and after fluorescence excitation at 740 nm [7,[9][10][11].…”

“…An analysis of the fluorescence parameters of chlorophyll a may provide a useful tool in the study of photosynthesis under stressful or unfavorable environmental conditions. The technique is widely employed in agriculture, horticulture, forest farming, seed production, plant farming, as well as storage and processing of fruit and vegetables [6].…”