Nat. Biotechnol. http://doi.org/bqr4 (2016)

The kerfuffle around genetically modified organisms is not stopping scientists from developing better crops. Cotton, an economically important plant, faces many threats. The herbivorous cotton bollworm (Helicoverpa armigera) can be contained with transgenic Bacillus thuringiensis plants, but sap-sucking whiteflies (Bemisia tabaci) must be killed using chemical pesticides. A team of researchers, led by Pradhyumna Kumar Singh and mostly from Lucknow, India, has now addressed this problem.

Credit: BILL BARKSDALE / DESIGN PICS / GETTY

Whiteflies have a broad range of hosts, but ferns are immune to the species. The authors screened fern extracts for whitefly toxicity and found that the edible fern Tectaria macrodonta was an efficient killer of the insect. The responsible protein, which demonstrated chitinase properties, was purified and cloned. Overexpression of the protein in cotton induced strong resistance during field trials by interrupting whitefly development cycles, without any cost in yield. Other insects, pathogenic or beneficial, were not affected.

More research is needed before this strategy can be commercially applied to cotton or other crops, but there is much to like about this study. Locally driven public research can be at the forefront of plant biotechnology, and transgenesis remains an important tool not to be dismissed. Finally, this interspecies transfer of one particular trait highlights the importance of biodiversity and conservation — even for plants that may not appear valuable today.