Background of BioSentinel

What is a BioSentinel?

It is a kind of ‘biological instrument’, an organism – typically a plant – that can help us understand constraints to our natural resource base, or use of it, and to act on these constraints.

Naturally occurring BioSentinels may include bacteria, honeybees, trees, native plants, or mosses and lichens. Bacteria are used to monitor toxic metals in soil (Trends in Biotech. 15: 500-506, 1997) whereas honey bees and their products, mosses and lichens are explored as potential BioSentinels of environmental pollution in Europe (Conti and Ceccetti, Environ Pollut. 114: 471-92, 2001; and Poikolainen et al., Sci Total Environ. 318: 171-85, 2004).  The classic example of a BioSentinel plant is the rose bush, which is planted in vineyards, to serve as BioSentinels for pest problems on grapes under certain environmental conditions (link).  Other examples include native plants species that are used to monitor airborne fluorides in Europe and USA (Weinstein and Davison, Environ Pollut. 125: 3-11, 2003).

Roses for background bioindicators
Roses at the ends of rows of grapevines in a vineyard show earlier symptoms of certain fungal diseases; the grower can choose what to do about the disease in the grapes based on what is seen in the rosebushes

BioSentinels can also be engineered.  These have been mainly designed to understand the role of nutrients in intracellular signaling processes in plants (Knight et al, 1991), measuring iron and phosphorous deficiencies (Eide et al., 1996; Vert et al, 2002; Hammond et al, 2003), assessing nuclear pollution caused by disastrous events (Kovalchuck et al, 1998), monitoring mineral toxicity and understanding physiological interactions within plants (Ezaki et al, 2000), and understanding ion dynamics in the cytoplasm and in the apoplast (Gao et al, 2004).

Proof of concept BioSentinels include transgenic Arabidopsis whose leaves turn from green to red after 3-5 weeks exposure to nitrogen dioxide gas indicating presence of landmines (, 2004), transgenic Arabidopsis plants that are metal specific BioSentinels (Environ Toxic.and Chemis 22: 175-181, 2003), transgenic Arabidopsis plants that monitor their own phosphorus status (Plant Physiology 132: 578-596), and transgenic Arabidopsis that were explored as sensitive BioSentinels of nuclear pollution caused by the Chernobyl accident (Nature Biotech 16: 1054-9, 1998).

In our project, we propose

  1. developing modules to engineer plants to become potential biological instruments
  2. coordinating through collaboration with other inventors/institutes access to other complementary modules to construct a pool of enabled technologies
  3. forming a community that will make these tools available under BiOS licenses.

We believe this will provide new opportunities for empowering local choices about what to do with local crops, rather than bringing in crops and methods from elsewhere. The proposal integrates the use of novel methods of molecular biology with the basic understanding of a field problem1. A biosentinel can be any species that can grow on the land of interest concurrently with the crop of interest, or at the best decision time. It receives a signal from the environment and translates it in a way that is readily observable by people who can then decide what to do about it. The signal could even come from the crop itself: for example, leaves beginning to wilt signals that fruit set will be hurt unless there is more water.  What is a modular approach and how it can be implemented?

1. Jefferson, R.A. (1993) ‘Beyond model systems: New Strategies, Methods, and Mechanisms for Agricultural Research‘, Annals of the New York Academy of Sciences 700: 53-73