Choice of plant and gene
So far my
focus has been on climate change induced problems and plants adapted to the
same. Researches about drought resistant GM plants have been very efficient and
I found out that there have been much more studies to this topic than I
expected. That’s why I decided to devote this blog entry to a quite different
upcoming issue: soil salinity. Salinity has increased in agricultural soils for
many reasons. Due to intensive fertilization there has been accumulation of
salt ions. Further to mention is the high amount of salt being distributed in
winter to defrost our roads. On one side, it can get directly into the soil by
draining away with the melting snow and on the other side it gets into our sewage
water system and then in public water bodies which are often used for
irrigation. Above all, drier summers mean less rain that could wash away the
salts and therefore mitigate the salinization.
As wheat is
the most cultivated crop in Switzerland, I’d like to design a highly
salt-tolerant wheat sort. Maas and Hoffman (1977) call wheat a moderately
salt-tolerant crop. [1] The newly created crop would be even more tolerant, as
this statement was issued in 1977 and soil salinity surely has increased since
then.
To enhance salt
tolerance the osmoregulation has to be modified. Two possible ways of doing so
are called “salt exclusion” as well as “tissue tolerance” and are described by
Munns R., James R. and Läuchli A. (2005) [2] Genes being responsible for these
strategies we find in halophyte. [3] Halophytes are plants that are adapted to
places with naturally higher salt concentration, e.g. beaches. I’d like to take
the appropriate gene from Thellungiella
parvula, known as salt cress. Its genome has been sequenced recently [4]
and is available in the gene bank. T. parvula is closely related to Arabidopsis
thaliana which has been used for genomic experiments numerously.
Arguments for further research
The Swiss
National Foundation should finance my project for the following two reasons:
- Wheat is the most commonly cultivated crop in Switzerland and a staple food worldwide. Hugh annually crop loss can be prevented by supporting researches concerning wheat.
- Soil salinity is a newer, upcoming issue in Swiss agriculture that is not yet paid enough attention at.
If I were
the person responsible for grants at the Swiss National Foundation I would
probably not finance this project due to the fact, that there already exist
some studies and experiments have been carried out on the subject. Furthermore,
with Switzerland’s commitments to produce more sustainable I’d rather support
studies that look for avoidance of salinization such as more efficiently
fertilisation or environmentally friendlier winter services.
References
[1] Maas EV,
Hoffman GJ. (1977). Crop salt tolerance – current assessment. Journal of the Irrigation
and
Drainage Division of the American Society of Civil Engineering 103, 115–134.
[2] Munns R., James R. and Läuchli A. (2006).
Approaches
to increasing the salt tolerance of wheat and other
cereals. Journal of Experimental Botany 57, 1025-1043
[3] Colmer TD et al. (2005). Improving salt tolerance of wheat and
barley: future prospects. Australian Journal
of Experimental
Agriculture 45, 1425-1443
[4] Dassanayake
M et al. (2011). The genome of the extremophile
crucifer Thellungiella parvula. Nature
Genetics 43, 913-918
