Biotechnology and Molecular Biology of Chloroplasts
Chloroplasts are members of the plastid family of organelles found in plant cells and are descended from ancient cyanobacteria. Plastids contain a small DNA genome (100-200 kbp) and a transcription-translation apparatus, which resembles that found in prokaryotes. Transplastomic technologies allow foreign genes to be transformed into plastids. The predominance of homologous DNA recombination in plastids allows foreign DNA to be targeted to specific sites in plastid DNA without bacterial vector sequences or selectable marker genes. These are highly desirable features characteristic of a new generation of "clean gene" transformation technologies. Clean gene technologies allow precise integration of genes of interest into the genomes of crops without undesirable DNA sequences such as antibiotic resistance genes. Removal of marker genes prevents the unnecessary release of antibiotic resistance genes into the environment. A further advantage of plastid transformation is that in many crops plastids are inherited from the maternal parent. Maternal inheritance enhances gene-containment in transplastomic plants by preventing the pollen-mediated spread of foreign genes. This will reduce, if not eliminate, the generation of weeds with foreign genes from transplastomic GM crops.
We are using plastid transformation in higher plants to study the function, regulation and maintenance of plastid genes. This basic research provides fundamental knowledge that underpins our applied projects on the expression of foreign genes in the plastids of crops and microalgae. The products of foreign genes accumulate to high levels when expressed in plastids (1-70% of soluble proteins). This makes the plastid a suitable site for expressing a wide range of foreign proteins. For example, pharmaceutical proteins, and proteins conferring herbicide and insect resistance. We are also transforming horticultural plants and crops with our vectors to increase the range of plant species amenable to plastid transformation. These projects will facilitate the widespread utilisation of transplastomic technologies in agriculture and plant biotechnology.
Plant Research News Engineered Chloroplasts Snip Out Antibiotic Resistance Genes
Jumping into the nucleus silences plastid genes
Maternal Inheritance of wheat chloroplasts
Avila EM, Gisby MF, Day A (2016)Seamless editing of the chloroplast genome in plants BMC Plant Biology 16 (1), 168 http://blog.globalplantcouncil.org/tag/synthetic-biology/
Full publication list: http://scholar.google.co.uk/citations?user=olDHoKUAAAAJ&hl=en