Reconfiguring Plant Metabolism for Biodegradable Plastic Production
Open Access
- 1 January 2020
- journal article
- Published by American Association for the Advancement of Science (AAAS) in BioDesign Research
Abstract
For decades, plants have been the subject of genetic engineering to synthesize novel, value-added compounds. Polyhydroxyalkanoates (PHAs), a large class of biodegradable biopolymers naturally synthesized in eubacteria, are among the novel products that have been introduced to make use of plant acetyl-CoA metabolic pathways. It was hoped that renewable PHA production would help address environmental issues associated with the accumulation of nondegradable plastic wastes. However, after three decades of effort synthesizing PHAs, and in particular the simplest form polyhydroxybutyrate (PHB), and seeking to improve their production in plants, it has proven very difficult to reach a commercially profitable rate in a normally growing plant. This seems to be due to the growth defects associated with PHA production and accumulation in plant cells. Here, we review major breakthroughs that have been made in plant-based PHA synthesis using traditional genetic engineering approaches and discuss challenges that have been encountered. Then, from the point of view of plant synthetic biology, we provide perspectives on reprograming plant acetyl-CoA pathways for PHA production, with the goal of maximizing PHA yield while minimizing growth inhibition. Specifically, we suggest genetic elements that can be considered in genetic circuit design, approaches for nuclear genome and plastome modification, and the use of multiomics and mathematical modeling in understanding and restructuring plant metabolic pathways.Keywords
Funding Information
- UT-Battelle, LLC (DE-AC05-00OR22725)
- Biological and Environmental Research
- Office of Science
- U.S. Department of Energy
- Center for Bioenergy Innovation
This publication has 104 references indexed in Scilit:
- OnPLS integration of transcriptomic, proteomic and metabolomic data shows multi-level oxidative stress responses in the cambium of transgenic hipI- superoxide dismutase Populus plantsBMC Genomics, 2013
- Transcription Activator-Like Effector Nucleases Enable Efficient Plant Genome EngineeringPlant Physiology, 2012
- An exogenous chloroplast genome for complex sequence manipulation in algaeNucleic Acids Research, 2011
- High Levels of Bioplastic Are Produced in Fertile Transplastomic Tobacco Plants Engineered with a Synthetic Operon for the Production of PolyhydroxybutyratePlant Physiology, 2011
- Unprecedented acetoacetyl-coenzyme A synthesizing enzyme of the thiolase superfamily involved in the mevalonate pathwayProceedings of the National Academy of Sciences of the United States of America, 2010
- The Role of Heterologous Chloroplast Sequence Elements in Transgene Integration and ExpressionPlant Physiology, 2010
- Plastics, the environment and human health: current consensus and future trendsPhilosophical Transactions B, 2009
- High-frequency modification of plant genes using engineered zinc-finger nucleasesNature, 2009
- Production of renewable polymers from crop plantsThe Plant Journal, 2008
- The complex structure of polyhydroxybutyrate (PHB) granules: four orthologous and paralogous phasins occur in Ralstonia eutrophaMicrobiology, 2004