Towards a synthetic biology platform for the production of in vitro plant biomass
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Date
16/11/2022Item status
Restricted AccessEmbargo end date
16/11/2023Author
Nirkko, Jessica Sinéad
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Abstract
To meet climatic targets, we require an urgent shift from the petroleum industry,
alongside concerted rewilding efforts to sustain vital natural carbon sinks and
biodiversity. Sourcing materials and fuels from plants is a sustainable alternative to
fossil fuels. Herein, plant cell suspension cultures (PCCs) are an attractive production
platform which retain the innate capabilities of plants without competing for arable
land. To-date, their use is mainly confined to the production of high-value products
such as medicines and additives. This thesis proposes to expand their useable range
to the alternative production of plant primary biomass products, including highly
cellulosic biomass for the creation of paper pulp or biofuels. The in vitro growth of
these materials would obviate the need for natural resource extraction and could
circumvent environmentally unfriendly processes involved in pulping.
Desired biomaterials usually rely on specific, differentiated cell types, such as
tracheary elements (TEs). PCCs however generally consist of dedifferentiated or stem-cell like cells. The work presented in this thesis therefore sought to create tools and
methods to differentiate PCCs, pursuing a main objective to achieve highly cellulosic,
de-lignified xylogenic cultures for the creation of in vitro paper pulp.
To realise these goals, a suite of novel genetic parts and protocols for use in plant
synthetic biology were developed and characterised. These were employed to create
constructs housing heterologous transcription factors known to be involved in xylary
differentiation, which were applied to drive cell fate determination in PCCs. In
addition, this work investigated phytohormone guided cell differentiation, applying
a statistical methodology to yield maximal in vitro TE differentiation, which was to be
used in conjunction with the created constructs.
Together, the findings, methods and tools generated in this thesis contribute towards
ongoing efforts to achieve sustainable, alternative production platforms for the
creation of essential biomaterials.