Uloga kompatibilnih osmolita u odgovoru biljaka na osmotski stres

undergraduate thesis

• Title (english): The role of compatible osmolytes in plant response to osmotic stress
• Author: Lena Bonassin
• Mentor: Mirta Tkalec (mentor)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2018, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology

Abstract

Biljke su tijekom rasta i razvoja izložene različitim okolišnim uvjetima. Nepovoljni uvjeti mijenjaju fiziološke procese, metabolizam, rast i razvoj biljke te dovode do promjena na staničnoj i molekularnoj razini. Osmotski stres se javlja zbog abiotičkih faktora kao što su povišeni salinitet, suša ili ekstremne temperature. Tijekom takvih uvjeta narušen je vodni potencijal biljke. Kako bi se osmolarnost povećala i smanjio gubitak vode, dolazi do sinteze kompatibilnih osmolita koji su organske molekule niske molekulske mase. Biljke nakupljaju različite spojeve: aminokiseline, tercijarne sulfonijeve spojeve, kvarterne amonijeve spojeve, šećere i šećerne alkohole. Osmoliti se nakupljaju u citoplazmi, gdje održavaju osmotski potencijal i fiziološku aktivnost stanice te je njihova biosinteza pod utjecajem okolišnih signala. Takvi spojevi ne utječu na stanične reakcije, a pomažu u toleranciji stresnih uvjeta stabilizacijom makromolekula i staničnih struktura, detoksifikacijom reaktivnih oblika kisika i održavanjem redoks sustava u stanici. Genskom manipulacijom gena za sintezu osmolita moguće je stvoriti biljke koje akumuliraju osmolite u povišenim koncentracijama te tako poboljšati njihovu sposobnost tolerancije stresnih uvjeta.

Abstract (english)

During growth and development plants are exposed to different environmental factors. Adverse conditions change the physiological processes, the metabolism, growth and development of the plant which affect the organism at a cellular and molecular level. Osmotic stress is a consequence of abiotic factors such as high salinity, drought or extreme temperatures. Those conditions disturb the water potential of the cell. To increase the potential and decrease water loss, compatible osmolytes are synthesized. Osmolytes are low molecular mass organic compounds. Plants accumulate different compounds: amino acids, tertiary sulphonium compounds, quaternary ammonium compounds, sugars and sugar alcohols which accumulate in the cytoplasm. Compatible osmolytes maintain the osmotic potential and physiological activity of the cell and are synthesized under control of environmental cues. Additionally, they stabilize the macromolecule and cell structure, scavenge reactive oxygen species and maintain the cell redox system without affecting the metabolic reactions of the cell. With genetic engineering of osmolytes biosynthetic pathways, it is possible to create plants accumulating osmolytes in high concentration which can improve their stress tolerance.

• Keywords: osmoliti; osmotski stres
• Language: croatian
• URN:NBN: urn:nbn:hr:217:144938
• Study programme: Title: Molecular Biology; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) molekularne biologije (sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) molekularne biologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2018-10-09 09:35:22