Researchers from the Instituto Gulbenkian de Ci?ncia (IGC) in Portugal have
discovered a novel genetic mechanism protecting plants from toxic zinc
levels. The researchers, led by Paula Duque, found that the ZIF2 gene
produces a protein that transports zinc ions into the vacuole of root cells,
and prevents its distribution to other plant organs.

To find out if the ZIF2 protein was protecting the plant against toxic
levels of zinc, plants either lacking ZIF2 or containing increased levels of
the protein were gathered. The researchers observed that, when there is high
levels of zinc, plants without ZIF2 were less tolerant to the metal; their
roots grew shorter, chlorophyll production was impaired, and ultimately, the
plant's biomass was reduced. The plants expressing more ZIF2 protein,
however, were able to cope better with high levels of zinc; roots grew
longer, and more chlorophyll and biomass were produced. These results
established that ZIF2 was important for plants to handle toxic zinc levels.

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