A scientific literature study
In the last
blog I wrote about upcoming challenges in Swiss agriculture. One of the main
subjects was the climate change and all its related issues like hotter and drier
summer or water scarcity. In todays blog I’m going to write about water
shortage and how this problem is being approached nowadays.
Specifically
the focus will be on the transgenic plants efficient use of water. My reference
article was written by Eleonora Cominelli and Chiara Tonelli at the University
of Milan with the title “Transgenic crops coping with water scarcity”.[1]
I chose
this paper as it is written in an understandable and still scientific way.
Furthermore, it gives a good overview of the basics of genetic modification of
plants in general and related to water stress in detail.
Cominelli
and Tonelli are stating the availability of water or more specific its absence
as one of the main causes of limited crop harvest worldwide. As environmental
factors or water situations are not changed that easily the authors see
promising possibilities in genetically modified plants. Therefore, they name
two different goals: develop plants that have improved water use efficiency and
improved drought resistance. These goals are approached by manipulating the
plants osmoregulation. In general this is achieved by inserting genes that lead
to an overproduction of osmoprotectants or an overexpression in transcriptional
regulators. Transcriptional regulators are often involved in plant reactions to
drought stress. Moreover, a plant mutant is mentioned in the paper that has
increased stoma closure and reduced stoma density what results in better
drought tolerance.
All the
approaches mentioned have successfully been tested on thale cress (Arabidopsis thaliana). Thale cress is
not used commercially and often being considered as weed. However, prosperous experiments
have been carried out with maize and rice too. Other papers also named tomato,
tobacco plants, barley, wheat, soybean and potato as being affected by water
scarcity and suitable plants for these methods.[2],[3],[4],[5]
For Swiss
agriculture wheat, barley, maize and tomato are the most interesting ones. Nevertheless,
personally I think scientific research focus should be on wheat, rice and
potato as these are staple food to millions of people worldwide. Furthermore, a
well-developed country like Switzerland with agriculture in comparably small
scale might also be interested in alternative solutions like drip irrigation
(Tröpfchenbewässerung), as already practiced with hors-sol tomatoes for
example.
References
[1] Cominelli E. and Tonelli C.
(2010). Transgenic crop coping with water
scarcity. Found 12.04.2014 on Pubmed: http://www.ncbi.nlm.nih.gov/pubmed/?term=transgenic+crop+coping+with+water+scarcity
[2] Begcy K. et al. (2011). A
novel stress-induced sugarcane gene confers tolerance to drought, salt and
oxidative stress in transgenic tobacco plants. Found 12.04.2014 on Pubmed: http://www.ncbi.nlm.nih.gov/pubmed/?term=A+Novel+Stress-Induced+Sugarcane+Gene+Confers+Tolerance+to+Drought%2C+Salt+and+Oxidative+Stress+in+Transgenic+Tobacco+Plants
[3] Bahieldin A. (2005). Field
evaluation of transgenic wheat plants stably expressing the HVA1 gene for
drought tolerance. Found 12.04.2014 on: http://onlinelibrary.wiley.com/doi/10.1111/j.1399-3054.2005.00470.x/abstract
[4] Quan R. et al. (2004). Engineering
of enhanced glycine betaine synthesis improves drought tolerance in maize. Found
12.04.2014 on Pubmed: http://www.ncbi.nlm.nih.gov/pubmed/?term=Quan%2C+R.+et+al.+%282004%29+Engineering+of+enhanced+glycine+betaine+synthesis+improves+drought+tolerance+in+maize.+Plant+Biotechnol.+J.+2%2C+477%E2%80%93486
[5] Hu H. (2006). Overexpressing a
NAM, ATAF, and CUC (NAC) transcription factor enhances drought resistance and
salt tolerance in rice. Found 12.04.2014 on Pubmed: http://www.ncbi.nlm.nih.gov/pubmed/?term=Hu%2C+H.+et+al.+%282006%29+Overexpressing+a+NAM%2C+ATAF%2C+and+CUC+%28NAC%29+transcription+factor+enhances+drought+resistance+and+salt+tolerance+in+rice.+Proc.+Natl.+Acad.+Sci.+U.+S.+A.+103%2C+12987%E2%80%9312992
Dear Petra
AntwortenLöschenI'd like to answer your optional question in this comment. In fact I used PubMed for the first time and it took me quite some time to get acquainted with it.
The task itself was interesting and challenging as well. However, I spent much more time on it than your proposed 2 hours. Just looking for and reading through papers took more than one hour. All in all I certainly spent at least 4 hours on this blog entry. Maybe this assignment could therefore be simplified a bit for next year.
Greetings Tina
Hi Tina
AntwortenLöschenJust reading your blog I could tell, you spent more than the assigned two hours....sorry! But the result is certainly very good, and I hope that you will be able to use pubmed more easily in the future when finding other references for your scientific work at the ZHAW...so I hope that all in all the additional work was worth it for you.
You found a lot of good references and were able to put them in context, stating your own opinion very clearly. Drip irrigation is also an interesting alternative - again, maybe it would be even better, if we could combine this?
I also know that in the US they level the fields using satelite information so the water runs very slowly from one side of the field to the other, I don't know if this is done in Switzerland too (probably not, as we still have more than enough water).
What I would also stress in drought tolerance is that we need much more research. Even if we do not need these plants right now, we will need them in the future - and it takes years (10-15 with classical breeding) from the first tests to getting the plants to the farmers!
Good work - thanks for your effort!
And I will think about simplifying some more!
Petra
PS. What I forgot: If your include the whole reference (with page no. and Journal etc.) there is no need to provide the link and the access date, as the paper will not be changed again. Please use this method when citing scinetific references. Thanks!
AntwortenLöschenDear Tina
AntwortenLöschenI liked your informations the manipulation of the plants osmoregulation. This was really new for me.
I think there is a lot work in progress to understand these processes better. Eventually new plants with drought resistance may come on the market.
I agree with you that the most important plants to work on are the staple foods. On the other hand I think that also other vegetables are important for a balanced nutritition and that research on these plants is important too.
Good and intresting work!
Greetings Noemi
Hi Tina
AntwortenLöschenYou wrote a very nice overview of drought tolerance GM plants! I also thought first about writing on this topic and am happy to read something about it now. For Swiss agriculture I think vegetables are the more important crops to work with drought tolerance. In Switzerland, vegetables need to be irrigated a lot already now. Meanwhile, e.g. wheat is already relatively drought resistant and endures also dry summers without irrigation. But you are certainly correct that GM staple foods bring the most benefit to worldwide population. Very good work!
Greetings Lukas