Universität zu Köln

Mishra, Priyanka ORCID: 0000-0003-1798-2306 (2019). Control of adventitious rooting in the alpine perennial Arabia alpina. PhD thesis, Universität zu Köln.

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Abstract

Successful adventitious root development ensures the efficient clonal propagation of alpine perennials under harsh environmental conditions, but the molecular basis of this process is not well understood. I used the alpine perennial Arabis alpina to explore natural variation of adventitious rooting and investigate the molecular basis of adventitious root development in alpine perennials. Plants of the A. alpina accessions, Pajares (Paj), Dorfertal (Dor), Totes Gebirge (Tot) and West Carpathians (Wca), and the perpetual flowering 1-1 (pep1-1) mutant were scored after growth in a long day greenhouse. The occupancy of adventitious roots on the hypocotyl, main stem, and axillary branches varied between genotypes. Especially, Wca plants produced adventitious roots on the main stem, which correlated with the higher expression of the A. alpina homolog of GH3.3. Exogenous auxin application by foliar spraying promoted adventitious root formation robustly in a genotype and age-dependent manner. I also applied auxin spray on vernalized Paj plants and scored the presence of adventitious roots on stems after plants were transferred in long day greenhouse. Adventitious roots developed from the vascular cambium cells specifically on younger internodes. High-throughput RNA sequencing revealed the differential regulation of auxin transporter genes in the internodes that produce adventitious roots compared to the ones that do not, indicating a key role for polar auxin transport during the induction of adventitious rooting after auxin spray. Auxin-responsive genes showed internode-specific transcript accumulation in response to auxin spray, which correlated with their rooting ability. In addition, transcripts of several meristem-associated genes were enhanced in the internodes that develop adventitious roots after auxin spray, indicating the establishment of root primordium during vernalization. Extended vernalization overcame the requirement to spray with synthetic auxin for the development of adventitious roots. After 21 weeks of vernalization, adventitious roots developed in young internodes and transcriptome profiling indicated the presence of initiator cells during vernalization and the involvement of auxin during the establishment of the initiator cells.

Item Type:	Thesis (PhD thesis)
Creators:	Creators Email ORCID ORCID Put Code Mishra, Priyanka priya1991mishra@gmail.com orcid.org/0000-0003-1798-2306 UNSPECIFIED
URN:	urn:nbn:de:hbz:38-100212
Date:	2019
Language:	English
Faculty:	Faculty of Mathematics and Natural Sciences
Divisions:	CEPLAS - Cluster of Excellence on Plant Sciences
Subjects:	Natural sciences and mathematics Life sciences Agriculture
Uncontrolled Keywords:	Keywords Language Arabis alpina English Adventitious root English Vernalisation English Alpine English Perennial English Auxin English Natural variation English
Date of oral exam:	15 February 2019
Referee:	Name Academic Title Albani, Dr. Maria Jun. Prof. Dr.
Refereed:	Yes
URI:	http://kups.ub.uni-koeln.de/id/eprint/10021