Adjustment of Broccoli Metabolism to Temperature Stress

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Ivana Sola

Faculty of Science, University of Zagreb, Croatia

: Expert Opin Environ Biol

Abstract

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Statement of the Problem: As sessile organisms, plants challenged with temperature stress undergo many adaptive mechanisms at molecular levels to maintain normal physiological function. Such adaptations consequently influence the phytochemical profile and bioactivity of their extracts. Due to their high nutritional value and very simple, fast, and cheap growing possibilities, microgreens are becoming increasingly prevalent in everyday consumption. A special attention is paid to Brassicaceae microgreens since they are rich in phenolics, vitamins, fibers, and particularly glucosinolates. In the scope of our work, we are investigating the effect of temperature as a climate parameter on the metabolism of microgreens and, consequently, their nutritional and health properties. We have analyzed the effect of air temperature as well as the temperature of water applied to the soil. Our goal is to single out variables that could potentially be used as biomarkers of temperature stress in broccoli. Hot water changed more variables (72% of young broccoli) than cold water (24%). Hot water increased the concentration of vitamin C by 33%, hydrogen peroxide by 10% and malondialdehyde by 28%, and proline by 147%. Total glucosinolates and soluble sugars were affected by hot and cold water in opposite ways, which suggests they could be used as biomarkers of hot and cold water stress in broccoli. High air temperatures increased total phenols, soluble sugars, carotenoids, quercetin, sinapic, ferulic, p-coumaric, and gallic acid in broccoli seedlings. Contrarily, total flavonoids, flavonols, phenolic acids, hydroxycinnamic acids, proteins, glucosinolates, chlorophyll a and b, and porphyrins were reduced. Minerals As, Co, Cr, Hg, K, Na, Ni, Pb, Se, and Sn increased at high temperatures, while Ca, Cd, Cu, Mg, Mn, and P decreased. The possibility of using temperature stress to grow broccoli enriched with compounds of interest to human health should be further investigated.

Biography

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Dr. Ivana Šola, Assoc. Prof., works in the Laboratory for Phytochemistry, Department of Biology, Faculty of Science, and University of Zagreb. Her main scientific interest is the plasticity of special plant metabolism under different environmental conditions. She currently leads one international and two national projects and is a collaborator on two scientific and one national infrastructure projects. She is the co-author of 29 scientific papers and one handbook and has participated in 72 international congresses. She spent 22 months in Germany for advanced scientific training. Dr. Šola holds lectures and practica in Fundamentals of Phytochemistry, Plant Bioactive Compounds, and Plants in Phytotherapy, Plant Anatomy, and Molecular Biology of Plants.