Amino acid analysis of GEM germplasm M. Paul Scott USDA-ARS Ames, Iowa

U.S. Corn Uses National Corn Growers Association, 2004 Annual value: $25 Billion

Impact of increased ethanol production Corn Prices Up Corn AcresUp Soybean priceDown Gov’t PaymentsDown Livestock income Slight decrease Overall Farm incomeUp N, P Lost to waterUp Soil ErosionUp Source: WRI policy note,2006 Marshall & Greenhalgh

Food and Fuel TransportationFeed Petroleum Grain hydrocarbons Starch Protein Oil Oilseeds Protein Oil Food

Food and Fuel Transportation Petroleum Feed Grain Starch Protein Oil Oilseeds Protein Oil Food 146 Billion Gallons Gasoline used/year in US 3.9 Billion Gallons EtOH in % of Corn crop

A solution Transportation Petroleum Feed Grain Starch Protein Oil Oilseeds Protein Oil Food Lignocellulosic Biomass Grain + Ethanol Co-products: DDGs

What corn traits are important? Yield (insect, disease, drought …) N use efficiency What about quality traits?

2.7 gal/bu $4.32/bu 18 lb/bu $0.68/bu Corn Co-products: DDGS, Solubles Grain Ethanol Production Protein 30% Fiber10-50% Fat10-20% Starch 5% Protein 10% Fiber3% Fat4% Starch 75% EtOH Starch Protein, Fiber, Fat Protein is concentrated by ethanol production! Problems are amplified!

Seed Fractionation Osborn, 1924 Water Albumins Salt Globulins Alcohol Prolamins “Zeins” Base Glutelins

Seed Proteins Embryo-vegetative Endosperm-storage Zeins SDS-PAGE Coomassie Blue Stained

Zeins Zeins are so abundant that they have a large impact on protein quality of grain Zeins are concentrated in ethanol co- products so their impact is even greater Zeins are nutritionally poor for non- ruminants –They are poorly digested –They are deficient in certain essential amino acids

Amino acid levels Corn vs. Egg

Methionine is the limiting AA in Poultry diets Lysine is limiting in poultry and swine diets, but can be supplemented inexpensively Tryptophan is limiting in swine diets Nutritionally limiting amino acids

What corn traits are important? Yield (insect, disease, drought …) N use efficiency For Ethanol: Fermentable starch Protein quality Available P For non-ruminant feed: Protein content Protein quality Available P Amino acid/ protein Absolute amino acid level

Questions about biofuel co- products How are differences in grain composition reflected in co-product composition? How will co-products be improved by processing? Can yeast components be used to complement grain components in co- products?

Evaluation of amino acid content of GEM germplasm About 80 GEM accessions / year selected for agronomics and past AA performance. Good lines are re-tested in subsequent years Lys, Met, Trp, Index (Lys,Met,Trp) Checks: –B101 (high Met) –B45o2 (high Lys, Trp) –B73xMo17, B73, Mo17, B45

Microbial assay for Met High Low Met Concentration

Evaluation of amino acid composition of GEM germplasm Two year Evaluation

Evaluation of amino acid composition of GEM germplasm Four year evaluation

Highlights of the GEM AA program DKXL212:N11a-139 Index was significantly higher than B73xMo17 in 4 yr tests. CHIS740:S1411a Met/protein was not significantly different that hi met check and significantly higher than other checks in 4 yr tests Seven XL370 and XL380 derived lines were not different than high met check in 2 yr evaluations.

Recommendations Evaluation of hybrids Selection within GEM “lines” Development of synthetics for recurrent selection

Divergent selection for amino acid content Advantages: Differences are magnified by selection in both directions Generate unique material to answer biological questions

Recurrent Selection BS31 BS31HM Selections (5 ears) Evaluation of 50 ears Intermating of Selections BS31HM C1 BS31HM C1 Selections (5 ears) BS31HM C2

Divergent selection for AA Content BS11BS31

Acknowledgements Mike Blanco and the GEM team Merinda Struthers Funding from USDA-ARS project funds Thanks for your attention!