Manipulation of agronomic traits in barley and lily for crop improvement
Publication Date
July 17, 2019
Creator
Abstract
Genetic manipulation offers opportunities to improve ornamental and agricultural crops, which can be used to increase their economic value, either by targeting specific traits or via general improvements to yield. Such improvements could have important impacts on the world economy, either by increased food production or via general economic development. This research has focused on the manipulation of genes aimed at improving agronomic traits in both Lily (Lilium) and barley (Hordeum vulgare L.) The traits targeted have been pollen development, with the aim of controlling fertility for hybrid breeding, and delayed senescence.
These transgenic approaches were adopted in Lilium to try to generate plants with altered fertility and senescence pathways. These approaches used promoters targeting expression to specific organs and developmental stages, which were tested by the use of GUS reporter genes. A range of constructs were therefore prepared for their future application to control gene expression in Lilium and Arabidopsis The Arabidopsis DYSFUNCTIONAL TAPETUM 1 (DYT1) transcription factor is expressed in the tapetum and is vital for regulation of tapetum development and pollen viability. Extending this information into cereal crops, such as barley, offers a potential mechanism for understanding the process of pollen development, and to control fertility to facilitate hybrid seed production. In this work, barley male sterile lines were obtained by over-expression of the barley HvDYT1 gene, which is proposed as the ortholog of the Arabidopsis DYT1 gene. These lines showed impaired pollen formation without affecting the development of the whole plant. This work demonstrates the role of HvDYT1 in barley pollen development and offers the potential for future control of fertility for hybrid seed production and to produce genetically engineered plants with controlled fertility.
Agricultural production of many economically important crops, fruit and vegetables are impacted by significant economical losses associated with early senescence. Delayed senescence is a key target for manipulation since it offers the potential for prolonged growth for increased yield, or via prolonged quality, as in the cut flower industry. Molecular studies of the genes involved in cytokinin metabolism and signalling, particularly altered expression of the ISOPENTENYLTRANS-FERASE (IPT) genes, have been used as approaches to modify senescence. In this work, transgenic barley plants were produced that contained the Arabidopsis IPT4 gene under the control of the Ubi1 promoter. These were assessed for the impact on growth and senescence progression.
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Item Type
ethesis
Thesis Type
PhD
Supervisors
Subjects (LC)
Associated Schools / Departments
School of Biosciences (UK)
eprints ID
44705
UoN Repository URI
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