Dose-dependent Plant-promoting Effect of Macroalgae Stypopodium schimperi Extracts in Solanum lycopersicum and Detection of Phloroglucinol Composition

Abstract

This study aimed to investigate using Stypopodium schimperi, brown alga extract, as a biofertilizer. Algae can be an essential bio-stimulant that increases plant growth and development. Brown algae especially have critical biological activities due to their high secondary metabolite content. This study also determined the biochemical and physicochemical composition and phenolic content of the S. schimperi, an alien brown alga in the Mediterranean Sea.Dose-dependent effects of these extracts on seed germination, root-shoot growth, seedling vigor index, and genome stability of Solanum lycopersicum plant were studied. Inductively coupled plasma mass spectrometry (ICP-MS) analysis revealed the primary elemental composition of the effective extract (10%). Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectroscopy showed phloroglucinol composition, the primary structural molecule of a phlorotannin, in the content of the extract. In addition, the phenolic content was determined by the Folin-Ciocalteu method, while the phenol-sulphuric acid method was used to determine carbohydrates by spectrophotometer. Genomic template analysis was conducted by calculating Inter Simple Sequence Repeats (ISSR) profile changes.Na, Mg, K, Fe, Mo, and Se were determined as elemental compositions of the 10% extract according to ICP-MS analysis. The ATR-FTIR resulted in four different spectral bands at 3350 cm(-1), 2936 cm(-1), 1636 cm(-1), and 1414 cm(-1), which were attributed to the phloroglucinol components. Our results showed that the highest phloroglucinol concentration could inhibit root growth and decrease genomic template stability (GST). The GTS difference between the control and 0.5% extract-treated group was approximately 91.38%, as revealed by ISSR analysis. The lowest GTS value (39.66%) was observed in the roots of S. lycopersicum treated with 5% extract.The present study demonstrated for the first time that a low concentration of S. schimperi extract could be used as a biofertilizer in agriculture. An alien macroalga that may be harmful to the ecosystem is being transformed into a beneficial one by being brought into the economy.