Vloga melatonina v rastlinah

Ilnikar, Kristina (author), Vodnik, Dominik (mentor)

Melatonin je indolska spojina, katere prekurzor za sintezo je aminokislina triptofana. Prisoten je v vseh kraljestvih živih organizmov, njegovo vlogo v rastlinah pa so začeli odkrivati šele po letu 1993. V različnih rastlinskih vrstah so opazili cirkadiani ritem nivoja melatonina. Ena izmed vlog, ki mu je bila pripisana, je funkcija antioksidanta. V različnih stresnih situacijah kot so sušni stres, ekstremne temperature, UV sevanje, slanost tal, prisotnost kemijskih onesnažil, melatonin sodeluje pri znižanju nivoja reaktivnih kisikovih in dušikovih zvrsti, izboljša redoks stanje celice ter stabilizira biološke membrane. Kot rastni regulator ureja rast korenin, poganjkov, aktivira rizogenezo in inhibira senescenco listov. Pri vseh teh procesih pa je pomembna njegova količina, saj je učinek pri mikromolarnih koncentracijah lahko ravno nasproten kot pri večjih koncentracijah. Izkazalo se je, da poveča učinkovitost fotosinteze, tako da učinkuje na fotosistem II ter omogoča listom, da v stresnih situacijah ohranijo visoko kapaciteto za fotosintezno vgradnjo CO2. Njegova biostimulatorna vloga je pomembna tudi za kmetijstvo.

• Language: Slovenian
• Keywords: fiziologija rastlin, melatonin, indolske spojine, rastni regulator, antioksidant
• Work type: Bachelor thesis/paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: BF - Biotechnical Faculty
• Publisher: [K. Ilnikar]
• Year: 2017
• PID: 20.500.12556/RUL-95050
• UDC: 581.1:547.752(043.2)
• COBISS.SI-ID: 8784505
• Publication date in RUL: 13.09.2017

ILNIKAR, Kristina, 2017, Vloga melatonina v rastlinah [online]. Bachelor’s thesis. K. Ilnikar. [Accessed 14 April 2025]. Retrieved from: https://repozitorij.uni-lj.si/IzpisGradiva.php?lang=eng&id=95050

Secondary language

• Language: English
• Title: The role of melatonin in plants

Abstract

Melatonin is an indolamine present in animals and other organisms. It was not until 1993 that this compound was detected in plants. It is an indolic compound derived from the amino acid tryptophan. The existence of endogenous circadian rhythms in melatonin levels has been demonstrated and the data suggest a central role of this molecule in the day/night cycles in plants. One of the most studied actions is its effect on biotic and abiotic stresses in the plant, such as drought, extreme temperature, chemical pollution, UV radiation. It acts as a scavenger of reactive oxygen and reactive nitrogen species (ROS and RNS), improves the redox status of the cell and stabilizes biological membranes. Melatonin as plant regulator regulates the growth of the roots, shoots, activates the rhizogenesis and inhibits the senescence of the leaves. In all these processes, its quantity is important. The effect in micromolar concentrations can be exactly opposite to higher concentrations. It has been shown that melatonin increases the efficiency of photosynthesis by affecting photosystem II and allowing leaves to mantain a high capacity for CO2 in stress situations. Its biostimulatory role is also important for agriculture.

• Keywords: plant physiology, melatonin, indole compound, plant regulator, antioxidant