Seed priming with corona discharge plasma modified growth performance, improved metabolism, and elicited production of tropane alkaloids in Datura inoxia seedlings; plasma technology for application in plant in-vitro cultures

Abstract

Abstract This study aims to monitor growth, biochemical, and anatomical responses of Datura seeds to cold plasma treatments for 0, 60, 120, 180 and 300 seconds. The plasma treatments of 60, 120 and 180 s improved the growth performance of seedlings, while the plasma treatment of 300 s drastically declined growth performance. The most pronounced response to the plasma treatments was on root growth and biomass. The proline concentrations in both root and leaves displayed a linear significant upward trend in response to the plasma treatments. The plasma treatment for 180s was the most effective method to increase tropane alkaloids in leaves about 2-fold. With increasing the plasma duration time from 60 to 300 s, the soluble phenols in leaves were linearly enhanced. The P60, P120, and P180 treatments augmented total protein concentrations by an average of 32.9%, while the P300 treatments significantly diminished protein content by 27.2%. The applied treatments also enhanced the soluble sugars in leaves by an average of 48%. The highest amounts of photosynthetic pigments (chlorophylls and carotenoids) were recorded in the P120 and P180 treatment groups contrasted with P300. The activities of two enzymatic antioxidants, including catalase and peroxidase, showed a similar upward trend to that of proline. The plasma priming also improved the phenylalanine ammonia lyase (PAL) activity (a secondary metabolism index) by an average of 65.6%. Further investigations are needed to optimize plasma treatment parameters and understand the underlying mechanisms to maximize its benefits while minimizing potential risks.