Regulacija spiralne filotaksije u cvjetnica

undergraduate thesis

• Title (english): Regulation of spiral phyllotaxis in flowering plants
• Author: Elizabeta Banić
• Mentor: Dunja Leljak-Levanić (mentor)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2014, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology

Abstract

Pravilan raspored biljnih organa oko stabljike, zvan filotaksija, stoljećima fascinira biologe i matematičare. Kao model za istraživanja filotaksije najčešće se koristi modelna vrsta A. thaliana. Filotaksija je prvenstveno određena uzorkom maksimuma auksina u vanjskom sloju vršnog meristema izdanka, koji određuje položaj lisnih i cvjetnih primordija. Maksimumi auksina određuju mjesto inicijacije primodrija, a okolni minimumi auksina djeluju kao inhibitorna polja, sprječavajući inicijaciju primordija. Za uspostavu gradijenta auksina dovoljna je pozitivna povratna sprega auksina i njegovog polarno raspoređenog eksportera PIN1. Simetrično raspoređeni importeri auksina, AUX1 i LAX, potrebni su za stabilizaciju uzorka, koncentrirajući auksin na površinu meristema. Sinteza auksina u području meristema regulirana je transkripcijskim faktorima plethora. Regulacija aktivnost pektin metilesteraza i njihovih inhibitora ima ulogu u promjeni mehanike stanične stijenke, što utječe i na filotaksiju. Definiranje granica meristema pomoću CUC2 i miR164 potrebno je za postmeristemsko održavanje filotaksije u odrasloj stabljici.

Abstract (english)

Regular positioning of plant organs around stem, called phyllotaxis, has fascinated both biologists and mathematicians for centuries. Model species A. thaliana is most used as model for phyllotaxis research. Phillotaxis is determined most importantly by pattern of auxin maxima in outer layer of shoot apical meristem, which positions leaf or flower primordia. Auxin maxima define the location of primordia initiation, and surrounding auxin minima act as inhibitory fields, preventing primordia initiation. Feedback loop between auxin and its polar exporter PIN1 is sufficient to establish auxin gradients. Symmetrically distributed auxin influx carriers AUX1 and LAX are needed to stabilize this pattern, concentrating auxin on meristem surface. Synthesis of auxin in meristem is regulated by plethora transcription factors. Regulating activities of pectin methyl-esterases and their inhibitors plays a role in modulating cell wall mechanics, which influences phyllotaxsis. Defining meristem boundary by CUC2 and miR164 is needed for post-meristematic maintaining of phyllotaxis in fully grown stem.

• Keywords: filotaksija
• Keywords (english): phyllotaxis
• Language: croatian
• URN:NBN: urn:nbn:hr:217:559038
• 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: 2017-12-06 10:05:52