Exogenous carnitine application enhances the growth of culantro ( Eryngium foetidum ) plants

Carnitine is an amino acid that is common to all living organisms and is involved in energy metabolism and stress tolerance in plants. In this context, the exogenous supply of carnitine may affect lipid metabolism, and consequently, plant growth. Eryngium foetidum L. (culantro) is a perennial herb with culinary and traditional medicinal uses owing to its chemical composition, which is rich in bioactive compounds. Considering the importance of E. foetidum and the potential of carnitine to modulate energy metabolism in plants, we investigated if exogenous application of carnitine can modulate the morphophysiological development of culantro plants. Plants (57-d-old) were leaf sprayed with water (control), 100 µM carnitine, and 10 mM carnitine. At 72 days after sowing, growth, photosynthetic pigment content, gas exchange parameters, and chlorophyll a fluorescence were measured. Plants treated with 100 µM carnitine were taller, had greater leaf area, and higher biomass accumulation and allocation to roots compared to the control. Carnitine reduced the maximum fluorescence and quantum efficiency of PSII, but did not affect gas exchange parameters. Here, 100 µM carnitine improved plant development and increased culantro yield. These results suggest that carnitine has potential as a growth regulator in culantro and other crops. This study will be fundamental to support future experiments on the practical use of carnitine as a bioregulator in plants as well as further studies on the biochemical and molecular mechanisms involved in this regulation.