Effects of Anandamide on Development, Growth and Cellular Organization of Physcomitrella Patens

Mosses are bryophytes with a simple cellular organization and distinctive growth stages. With their unique lipid profile, most mosses are also tolerant to various stressors. A ubiquitous class of bioactive fatty acid ethanolamides in eukaryotes called N-acylethanolamines (NAEs) also occurs in the moss Physcomitrella patens. Unlike in higher plants, where saturated and unsaturated NAE types are limited to those with acyl chains 12C to 18C, P. patens also contains anandamide, NAE 20:4. In higher plants, NAEs are most abundant in desiccated seeds and mediate plant growth, development, cellular organization and response to stress, in an abscisic acid (ABA)-dependent or independent manner. In mammals, NAE 20:4 acts as an endocannabinoid ligand and mediates a multitude of physiological responses. This unique NAE type, NAE 20:4 is hypothesized to effect development, growth and cellular organization of P. patens. To determine the role of NAEs in moss development, NAE content and composition in protonema, early and late gametophyte stages, and sporophytes, will be quantified from their total lipid extracts, using selective lipidomics. The effects of anandamide on growth will be studied by culturing moss in the presence of exogenous NAE 20:4 in a dose-dependent manner. Temporal changes in growth patterns will be determined by the evaluation of digital images using Image tool. The effect of anandamide on cytoskeletal organization will be visualized by immunostaining the phyllodes exposed to NAE 20:4 and observing them under confocal microscope. Preliminary results indicate that the endogenous NAE content and composition is variable, depending on the developmental stage and that NAE 20:4 is a potent negative regulator of moss growth. More detailed studies are expected to provide novel insights into the role NAEs, specifically NAE 20:4 might play in mediating growth and development of seedless plants