TCE Uptake by Transgenic Plants Plants used for phytoremediation take up pollutants, then transport the chemicals to cells that store, detoxify, or release them to the air. Researchers are now engineering transgenic plants that have an enhanced ability to carry out these tasks.

Sharon Doty and her colleagues published the results of their efforts to genetically engineer plants for phyroremediation of soil and air contaminated with organic solvents. The researchers used Agrobacterium tumefaciens (Section 15.7) to deliver a mammalian gene into poplar plants. The gene encodes cytochrome P450, an enzyme involved in the breakdown of a range of organic molecules, including solvents such as TCE. FIGURE 28.1 shows data from one test on the resulting transgenic plants.

FIGURE 28.1 TCE uptake from air by transgenic poplar plants.

Individual potted plants were kept in separate sealed containers with an initial level of TCE (trichloroethylene) around 15,000 micrograms per cubic meter of air. Samples of the air in the containers were taken daily and measured for TCE content. Controls included a tree transgenic for a T_i plasmid with no cytochrome P45D in it (vector control), and a bare-root transgenic tree (one that was not planted in soil).

Assuming no other experiments were done, what two explanations are there for the results of this experiment? What other control might the researchers have used?

To assume: The possible explanation and control that might the researchers have used to for the given experiment.

Introduction: Transgenic plants are the plants whose genomes are altered or modified by inserting a desired foreign gene using certain genetic engineering techniques. The production of transgenic plant was intended for the expression of desired trait in the plants that does not occur naturally in them. Transgene (foreign gene) can be from unrelated origin.

Nowadays, transgenic plants play a significant role in phytoremediation (using plants to clean up the environment). The transgenic plants have the transgene, which makes the plant efficient to remove, utilize, and detoxify the pollutants. It can be used to clean up an important soil and air contaminant. Transgenic poplar plants that could express cytochrome P450 enzyme were produced to check their efficiency to clean the Trichloroethylene (TCE).

Refer Figure 28.1, “TCE uptake from air by transgenic poplar plants” in the textbook. Six poplar plants were chosen for the experiment. Initially, individual plants were placed in a sealed container with around 15,000 micrograms per cubic meter of TCE. Every day, the sample air containing TCE were taken from the container and measured. A control was set with a transgenic plant’s Ti vector with no cytochrome P450 enzyme and also a bare-rooted or unplanted transgenic plant.

There are two possible explanations for the given experiment...