Plants producing a biodegradable polyester were smaller, never produced
seeds and showed severe changes in metabolism.
Arabidopsis thaliana (Thale Cress; mustard family).
Three genes derived from bacteria that are needed for polyhydroxybutyrate
(PHB) production, which is a biodegradable polyester, were transferred
into the mustard Arabidopsis. The gene was fused to the cauliflower
mosaic virus (CaMV-35S) promoter so that the genes would be expressed in
all parts of the plant.
Transgenic plants that produce a biodegradable polyester.
Six transgenic lines did accumulate PHB in their chloroplasts. The
greatest amount of PHB was 4% of total plant fresh weight.
The more PHB in a transgenic line, the smaller the plants grew. Growth
retardation was evident even in those plants that accumulated very
The plants with the most PHB never produced seeds.
The plants showed slight chlorosis (yellowing of leaves).
Metabolic profiling of sixty metabolites suggested that "severe
changes in metabolism result from the production of PHB in these lines"
(p. 845). The amounts of sugars, alcohols, amino acids and organic acids
changed markedly while-to the surprise of the researchers-the amounts
and composition of fatty acids did not change.
Bohmert, K., I. Balbo, J. Kopka, V. Mittendorf et al. (2000). "Transgenic
Arabidopsis Plants can Accumulate Polyhydroxybutyrate to Up to 4% of
Their Fresh Weight," Planta vol. 211, pp. 841-45.
Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam,
Germany; University of Fribourg, Switzerland; University of Lausanne,
Switzerland; Freie Universität Berlin, Germany.
German Ministry of Agriculture (partial).
Not on the market as of 2008.
Copyright 2008 The Nature