PERSPECTIVES
Hiring cell gatekeepers – ABC transporters in plant biotechnology

In order to survive in the environment, a cell has to be able to maintain a constant influx of chemical substances

which provide nourishment, it also has to dispose of endogenous or exogenous toxins as well as must perceive

and exchange signalling molecules. Such movement needs to be selective and organised. This prerequisite is realised

by an array of membrane transporters, channels, carriers and pumps. ATP-binding cassette (ABC) transporters

constitute the largest family of membrane transport proteins found in all organisms in every life domain.

Researches in recent years have shown recognition of the role that plant ABC transporters play in hormone

signalling, heavy metal tolerance, as well as natural product trafficking. In this review article we present plant

ABC transporters, their characteristic modular structure and importance in plant physiology. We also point out

the recent discoveries that describe their role in drought tolerance by modulation of abscisic acid traffic, and their

involvement in subcellular compartmentation of exogenous toxic compounds and/or natural products. Alongside

the gradually increasing number of results in fundamental research, plant ABC transporters begin to emerge as

novel targets for applied science. We present an outline of the work and ideas that may link genetic engineering

of ABC transporters with plant biotechnology. A particular attention is paid to the possibility of alleviating the

heavy metal stress and the production of secondary metabolites.