Improving Nutrient Use Efficiency in Barley Opportunities and Challenges Allen Good University of Alberta July 26, 2010
Nutrient Use Efficiency enters the world stage
Nutrient Efficient Traits; A Large Market Phosphate 40 MMt Nitrogen 100 MMt Current economic value of N based fertilizers is between $80-$100B annually Potassium 26MMt
Nitrogen Fertilizer Use Tragedy of the Commons With an unmanaged commons overuse of resources reduces carrying capacity, ruin is inevitable. Science vol 162, pp. 1243, 1968 G. Hardin UC Santa Barbara
Impact of Fertilizer Runoff on Aquatic and Marine Ecosystems
World N Fertilizer Consumption Year Price ($/Mton) World EU Denmark China Cons (MMton N) Value ($US B) 1987 425.3 75.8 $32.2 1997 610.4 81.3 $49.6 2007 795 100.6 $80.0 2012 869 103.2 $89.7 2030 1220 126.9 $154.8 Cons Cons Cons Cons Cons Cons (Mton N) (kg/ha) (tons of N) (kg/ha) (Mton of (kg/ha) N) 30,296 127 367,000 142 18,566 138 15,538 101 283,000 120 25,357 185 13,264 114 172,466 75 34,774 247 13,000 114 170,000 74 37,578 267 13,000 114 170,000 74 54,493 388
Nitrogen Use Efficiency; Why Invest Fertilizers represent the major input costs for producers. Seed sales are in the $15-20B annually, whereas N based fertilizers alone are worth $100B. We believe that it will be possible to produce crop plants that can fix their own N. In the short term, our focus is on improving the efficiency with which plants take up and use N.
Improving Nitrogen efficiency can occur in two ways Yield Increase Yield Cost Decrease Applied Nitrogen
70% of Nitrogen Fertilizer is Lost N Fertilizer Application Root 30% 70% Loss to Leaching & microbes By capturing more N, yield efficiency can be gained
Gaseous losses N 2 0, NO, N 2 NH 3 volatilization Photorespiration Precipitation N uptake N uptake N remobilization Fertilizer N Soil Available N Plant N Grain Yield RE PE Recovery Efficiency Physiological Efficiency Legumes Fixed N Leaching Unavailable N Sources and fates of N in plants and the environment Good et al. (2004) Trends Plant Science 9:597-605
Key Steps in the Nitrogen Pathway NO 3 - NO 3 - Nitrate Transporters NR NO 2 - NiR Cell Wall Gln GS NH 4 + NH 4 + GS/GOGAT Cycle Ammonia Transporters Amino Acids Glu AlaAT Pyruvate KG Alanine
Modelling of AlaAT A B Protein structure of the Barley AlaAT protein. A. The AlaAT protein dimer. B. The location of the active sites in an AlaAT dimer.
Nitrogen efficient canola; Current status Current status -Sublicenced to Monsanto in 2004, for use in canola. -Arcadia and Monsanto have conducted confined field trials on material based on this genetic construct in 2004, 2005, 2008 and 2009, btg26/alaat canola Good et al. (2007) -To date, there is no indication that there will be a commercial release of a canola variety with this trait incorporated, in the immediate future.
Transgenic OsAG1:AlaAT lines; Nitrogen efficient Current status - Currently, genetic constructs based on this gene and concept have been introduced into canola, maize, wheat, barley, rice, turf grass and sugar beet. Transgenic Line- AGR-1/8 Control - The efficacy of these constructs has not been reported to date, other than our publications. Shrawat et al. 2008
Gus expression in roots of transgenic rice plants RH Lateral roots Lateral roots Line-15 Line-15 Lateral roots Line-15 Lateral root Line-15
Gus expression pattern in primary root of transgenic lines 3 2 1 Primary root Apical meristem Root tip RH 3 2 1 V Apidermis
How does AlaAT increase N uptake and NUE?
Current Research Directions 1. Determine mode of action of AlaAT. 2. Evaluate different promoters associated with AlaAT. 3. Evaluate different genes expressed under regulated tissue specific expression. 4. Evaluate different variants of AlaAT. 5. Use a genetics approach in barley to determine genes involved in NUE and the interaction of different genes in different genetic backgrounds.
What have we accomplished 1. Have shown that NUE can be improved in some crop plants, using a targeted transgenic approach. 2. Emphasized the need to look closely at how we regulate different genes using tissue specific expression. 3. Have emphasized the need for an co-ordinated transgenic, genetic and agronomic approach.
Private Sector Investment is funded through sales of certified seed Crop % Certified Seed % Projected Investment Corn 98% 12% Cereals 18% 2% Soybean 87% 10% Canola 92% 74% CSTA Investment Survey and Blacksheep Study for CPTA
What are some of the challenges to developing these 2 nd generation traits? Regulatory; The cost of regulatory compliance has made most traits uneconomic for the more minor crops. We lack any ability to directly compare different gene constructs in the field. We are increasingly losing our ability to develop young scientists and novel ideas. This is, in part due to the current funding models.
What are the funding challenges? We no longer have a viable Discovery grants program which will allow young researchers to survive. For targeted research, the PI model does not work. The large scale programs that have been developed have a number of inherent problems which include; The inability to fund truly novel work. The need for large, PC teams. The need to have an international star ensures that only established scientists can lead any initiative. The need for a constant accounting of what has been done.
What we need to do as a community? We need to be better at selecting good leaders and good managers. We need to recognize that while governments can dictate how much funding flows to an area, they are not capable of identifying innovative or good science. We need to recognize that we have become the justification for an increasing large scientific bureaucracy which I would argue significantly decreases our scientific competitiveness.
What we need! JFK didn t say; We want to be indisputably recognized as leaders in space research. He said; We will put a man on the moon by the end of the decade.
Summary The 2 nd generation of traits will be much more challenging than believed. We need to have ways of testing genes and novel concepts, in the real world. (A phenotyping facility). We need to show more leadership and better management of how and what science is funded. We need to be more vocal in the concern over the direction of science funding in Canada.
Thank you to the group that does the real work. Funding provided by; NSERC, Genome Canada, Alberta Agriculture, Alberta Crop Industry Development Fund