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From 2011.igem.org

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Informing Design

We consulted numerous experts in various fields to ensure that the design of the AuxIn system respects all relevant social, ethical and legal issues. One module of our system, Gene Guard, is a direct result of brainstorming around the issues involved in the release of genetically modified organisms (GMOs). Although we have only reached the proof of concept stage, we have put a lot of thought into how AuxIn may be implemented as a product and the legal issues that would be involved.

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Implementation

Although our project is only at the proof of concept stage, we have done extensive research to be able propose a future implementation plan for AuxIn. With the advice of several experts in various fields, we decided to market our product in a pre-coated seed package. Although proof of concept has only been tested with E. coli on Arabidopsis roots, we hope that future work will enable the production of a general seed coat that can be applied to any seed type to tailor to the needs of different ecosystems.

AuxIn also has potential as a platform technology in that we can deliver virtually any compound to plant roots via our Phyto-Route module. The advantage of this approach, over direct genetic modification of plants, is that the same product can be applied (in theory) to any plant type, including those already established in the soil.

Because soil erosion and desertification are posing great threat all over the world, we plan to sell AuxIn to industrialized countries such as the USA and Australia, to protect barren land or restore depleted crop lands. With this revenue we can provide AuxIn to pre-established local organisations in developing areas free of charge.

The figure below shows an implementation pipeline diagram for our project. It will need to go through extensive safety testing and optimisation before implemented.

Predicted developmental stages of the AuxIn project. Source of biology, toxicology, and environment data: CropLife International, as supplied by Dr Stuart Dunbar.

Problem in the Sahel

Africa is the region most affected by desertification. Two thirds of the continent is covered by dryland which is used extensively for agricultural production. Over-cultivation has led to large scale degradation, exacerbated by frequent drought, leading to extreme food scarcity for some 650 million people who are dependent on the affected land. If the degradation trend continues, it is estimated that two thirds of Africa’s arable land may be lost by 2025 (FAO 2009). The Sahel is one of the areas severely affected by soil erosion.

What’s being done now

In an effort to combat desertification, 11 countries along the southern border of the Sahara are involved in the Great Green Wall project. With the help of international aid, the objective is to cover 8,000 km of dryland with vegetation as a protective barrier from erosive forces. Local governments are endorsing efforts to plant these trees. This project is also supported by the UN and EU. Planting of shrubs and trees in arid areas at risk of desertification is hugely beneficial in its ability to reintroduce soil nutrients as well as protecting the land from erosive forces. However, the operation is extremely time consuming and will take a long time before it is established.

How we can improve this

Our project will focus on distributing coated acacia seeds. African acacia trees are drought resistant species (Flagg, 1991) that provide many benefits: they can be used as a source of income as their gum is valuable. In addition, they provide shelter to small animals and protect crops from erosive forces such as rain and wind. They also restore soil fertility. Acacia trees are already commonly found in the Sahel area (Safriel et al., 2005). The benefits of planting acacias have already been demonstrated in the Acacia Operation Project, involving six sub-Saharan countries that successfully restored 13,000 hectares of land (UNCCD, 2011). The acacia genus is also one of the main plant types implemented in the Great Green Wall project.

Adequate land coverage with protective vegetation is extremely time consuming and seedlings will take time to become established and the plants need to overcome several hurdles before establishment (Figure 1).

Figure 1. Obstacles encountered throughout the acacia life cycle (Midgley & Bond, 2001).

AuxIn is a microbially enriched seed coat that improves the establishment of seedlings. This is achieved via the microbial secretion of the naturally occurring auxin, indole 3-acetic acid, which improves lateral root growth, thereby stabilising soil.

The use of seed coats has already been successfully implemented in common agricultural practice, supplying many different compounds including pesticides to plants, and will provide easy application of the product in affected areas. We are planning to develop a device that will facilitate the seeding of acacias into soil. This would eradicate the need to plant seedlings, a very time-intensive practice. This would make our product economically sound as it would save resources and time.

Production would be carried out by the AuxIn Foundation. We are planning to use similar strategies in developed countries such as the US, Australia and Israel to combat desertification and sell our project for profit in these areas. The technology can be applied to any seed type required for the area. Desertification is a global problem and we do not just want to target it on a local scale. The profits generated by this will be used to finance our efforts in combating desertification in developing countries.

Distribution will be handled by local authorities. There are many social and economic factors involved in combating desertification and we plant to address them as well as we can.

What downstream effects this will have

Soil affects the climate and biodiversity and leads to often irreversible desertification (Figure 2).

Figure 2. (UN, Ecosystems and human well-being - Desertification synthesis).

Roots increase the stability of soil and prevent erosion (Gyssels & Poesen, 2003). In addition, trees provide cover and protect nearby fauna and flora. In areas prone to soil erosion, this is especially important as rainfall tends to be rare but when it does occur, it is often very intense and easily leads to topsoil being washed away. Roots are also important carbon sinks. Increasing root biomass is therefore very likely to improve the carbon budget of the plants we are seeding (Dr Alexandru Milcu, oral communication).

Problem in India

30% of landmass in India is comprised of drylands (Government of India, 2006) and desertification is leading to crop losses of up to 41% in eastern Himalayan areas (Sharda et al., 2010), which are recognised as biodiversity hotspots (Government of India, 2006). Soil erosion is caused by a plethora of factors, including wind, water, vegetation and man-made erosion (Figure 3). Water degradation and erosion are the two biggest factors (Ajai et al., 2009). INSERT FIGURE

Figure 3. Causes of and areas affected by soil erosion in India (Ajai et al., 2009).

Subsistence farming and biological diversity are at threat.

What's being done now

The Indian national government has started efforts to improve the livelihoods of people throughout the country, including improving literacy, closing the gender gap and promoting education as well as improving the water supply. In addition, a number of projects have been put in place to improve soil (Government of India, 2006). A thorough report of which measures are being undertaken by the national government can be found here.

How we can improve this

In this area, our project will take a similar focus.

References:
Flagg, C. (1991) Acacia tortilis: Fodder tree for desert sands. The Forest, Farm, and Community Tree Network.
Safriel, U. et al. (2005) Dryland systems. In: Ecosystems and human well-being: Current state and trends. (Online) Available from: http://www.maweb.org/en/Condition.aspx (Accessed on 16 August 2011).
UNCCD (2011) Desertification: a visual synthesis. (Online) Available from: http://www.unccd.int/knowledge/docs/Desertification-EN.pdf (Accessed on 12 August, 2011).
Midgley, J. & Bond, W. (2001) A synthesis of the demography of African acacias. Journal of Tropical Ecology 17:871-886.
Gyssels, G. & Poesen, J. (2003) The importance of plant root characteristics in controlling concentrated flow erosion rates. Earth Surface Processes and Landforms 28:371-384.