Utjecaj proteina ASR1 na solni i osmotski stres kod biljaka

undergraduate thesis

• Title (english): The effects of ASR1 protein on salt and osmotic stress in plants
• Author: Tea Rogić
• Mentor: Biljana Balen (mentor)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2010, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology

Abstract

Biljke su izložene djelovanju abiotičkog stresa na dnevnoj bazi. ASR1 je visoko-nabijeni, biljno-specifični protein male molekulske mase (13 kDa), koji sudjeluje u staničnom odgovoru na stres a lokaliziran je u citoplazmi i jezgri stanice. Posjeduje DNA-veznu aktivnost koja ovisi o prisustvu cinka – on potiče prijelaz proteina ASR1 iz nesmotane u smotanu konformaciju. Smatra se da su se današnji oblici gena asr razvili iz jedne porodice koja je kroz vrijeme različito divergirala, ovisno o vrstama u kojima su se geni našli tj. smatra se da su pratili model usklađene evolucije. Dokazi tome su nedavne duplikacije gena asr3 iz asr4 i homologija između asr4 iz rajčice i asr6 iz riže. Iako se o njemu još uvijek zna vrlo malo, smatra se da jezgreni oblik proteina ima funkciju transkripcijskog faktora koji potiče niz signalnih puteva borbe protiv učinka abiotičkog stresa. Za citosolni, nesmotani oblik se još uvijek ne zna kako pridonosi održavanju homeostaze, ali smatra se da bi prijelaz proteina iz jednog oblika u drugi i iz jednog staničnog odjeljka u drugi mogao biti jedan od načina regulacije aktivnosti ovog proteina. Sve u svemu, zna se da njegova ekspresija utječe na povećanje otpornosti biljke na solni (smanjenjem neto nakupljanja natrija u stanici) i osmotski (preko uloge hidrofilina) stres, iako tek slijedi razvoj teorija i metoda pomoću kojih će biti lakše shvatiti njegovu pravu ulogu u biljnim stanicama te konstruirati transgenične biljke koje će biti otpornije na naseljevanje novih staništa i tolerantnije na nove uvjete koje će tamo susresti.

Abstract (english)

Plants are exposed to effects of abiotic stress factors on a daily basis. ASR1 is a small (13 kDa) highly-charged, plant-specific protein, localised in citoplasm and nucleus, which takes part in cell's stress-defending pathways. It has a zinc-dependent DNA-binding activity – zinc enables the protein to transform from unfolded to fully folded form. It is believed that the asr genes, which we know of today, developed from a single gene family, probably through a model of concerned evolution. The evidence for that are gene duplications which took place recently (which state that asr3 originated from asr4) and homology between tomato asr4 and rice asr6 genes. Although we have much to learn about ASR1's functional and biological function, it has become clear that it's nuclear form plays role of a transcription factor, which induces a downstream of genes and signal pathways included in plant's response to abiotic stress. It is not yet known how does the cytosolic form of the protein takes part in homeostasis, but it is thought that it's transformation to folded state and transportation to the nucleus have something to do with the way this protein's activity is regulated. Nevertheless, we do now know that it's expression induces the plant's ability to tolerate damage which took place after plant's been exposed to stress. It does it so by lowering the net uptake of sodium in the cell (contribution to salt stress tolerance) and through it's role as a hydrophilin. Anyway, we've only just began to realise it's biologycal importance as a mean to construct transgenic plants which will be more tolerant to abiotic stress factors and will grow more sucessfully in new habitats.

• Keywords: biljke; ASR1; solni stres; osmotski stres
• Keywords (english): plants; ASR1; salt stress; osmotic stress
• Language: croatian
• URN:NBN: urn:nbn:hr:217:082294
• 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: 2018-03-29 10:00:13