Phenotypic and Transcriptional Analysis of Divergently Selected Maize Populations Reveals the Role of Developmental Timing in Seed Size Determination.
Seed size is a component of grain yield and an important trait in crop domestication. To understand the mechanisms governing seed size in maize (Zea mays), we examined transcriptional and developmental changes during seed development in populations divergently selected for large and small seed size from Krug, a yellow dent maize cultivar. After 30 cycles of selection, seeds of the large seed population (KLS30) have a 4.7-fold greater weight and a 2.6-fold larger size compared with the small seed population (KSS30). Patterns of seed weight accumulation from the time of pollination through 30 d of grain filling showed an earlier onset, slower rate, and earlier termination of grain filling in KSS30 relative to KLS30. This was further supported by transcriptome patterns in seeds from the populations and derived inbreds. Although the onset of key genes was earlier in small seeds, similar maximum transcription levels were observed in large seeds at later stages, suggesting that functionally weaker alleles, rather than transcript abundance, may be the basis of the slow rate of seed filling in KSS30. Gene coexpression networks identified several known genes controlling cellularization and proliferation as well as novel genes that will be useful candidates for biotechnological approaches aimed at altering seed size in maize and other cereals.
Department of Energy Great Lakes Bioenergy Research Center (R.S.S., M.W.B., N.d.L., S.M.K.), Department of Agronomy (R.S.S., M.W.B., P.K., N.d.L., S.M.K.), and Department of Botany (E.P.S.), University of Wisconsin, Madison, Wisconsin 53706;Department of Agronomy and Plant Genetics, University of Minnesota, St. Paul, Minnesota 55108 (C.N.H.);Department of Energy Great Lakes Bioenergy Research Center (K.L.C., C.R.B.) and Department of Plant Biology (K.L.C., C.R.B.), Michigan State University, East Lansing, Michigan 48824; andUnited States Department of Agriculture-Agricultural Research Service, Corn Insects and Crop Genetics Research Unit, Ames, Iowa 50011 (S.D.).
Rajandeep S
RS
Sekhon
Department of Energy Great Lakes Bioenergy Research Center (R.S.S., M.W.B., N.d.L., S.M.K.), Department of Agronomy (R.S.S., M.W.B., P.K., N.d.L., S.M.K.), and Department of Botany (E.P.S.), University of Wisconsin, Madison, Wisconsin 53706;Department of Agronomy and Plant Genetics, University of Minnesota, St. Paul, Minnesota 55108 (C.N.H.);Department of Energy Great Lakes Bioenergy Research Center (K.L.C., C.R.B.) and Department of Plant Biology (K.L.C., C.R.B.), Michigan State University, East Lansing, Michigan 48824; andUnited States Department of Agriculture-Agricultural Research Service, Corn Insects and Crop Genetics Research Unit, Ames, Iowa 50011 (S.D.).
Candice N
CN
Hirsch
Department of Energy Great Lakes Bioenergy Research Center (R.S.S., M.W.B., N.d.L., S.M.K.), Department of Agronomy (R.S.S., M.W.B., P.K., N.d.L., S.M.K.), and Department of Botany (E.P.S.), University of Wisconsin, Madison, Wisconsin 53706;Department of Agronomy and Plant Genetics, University of Minnesota, St. Paul, Minnesota 55108 (C.N.H.);Department of Energy Great Lakes Bioenergy Research Center (K.L.C., C.R.B.) and Department of Plant Biology (K.L.C., C.R.B.), Michigan State University, East Lansing, Michigan 48824; andUnited States Department of Agriculture-Agricultural Research Service, Corn Insects and Crop Genetics Research Unit, Ames, Iowa 50011 (S.D.).
Kevin L
KL
Childs
Department of Energy Great Lakes Bioenergy Research Center (R.S.S., M.W.B., N.d.L., S.M.K.), Department of Agronomy (R.S.S., M.W.B., P.K., N.d.L., S.M.K.), and Department of Botany (E.P.S.), University of Wisconsin, Madison, Wisconsin 53706;Department of Agronomy and Plant Genetics, University of Minnesota, St. Paul, Minnesota 55108 (C.N.H.);Department of Energy Great Lakes Bioenergy Research Center (K.L.C., C.R.B.) and Department of Plant Biology (K.L.C., C.R.B.), Michigan State University, East Lansing, Michigan 48824; andUnited States Department of Agriculture-Agricultural Research Service, Corn Insects and Crop Genetics Research Unit, Ames, Iowa 50011 (S.D.).
Matthew W
MW
Breitzman
Department of Energy Great Lakes Bioenergy Research Center (R.S.S., M.W.B., N.d.L., S.M.K.), Department of Agronomy (R.S.S., M.W.B., P.K., N.d.L., S.M.K.), and Department of Botany (E.P.S.), University of Wisconsin, Madison, Wisconsin 53706;Department of Agronomy and Plant Genetics, University of Minnesota, St. Paul, Minnesota 55108 (C.N.H.);Department of Energy Great Lakes Bioenergy Research Center (K.L.C., C.R.B.) and Department of Plant Biology (K.L.C., C.R.B.), Michigan State University, East Lansing, Michigan 48824; andUnited States Department of Agriculture-Agricultural Research Service, Corn Insects and Crop Genetics Research Unit, Ames, Iowa 50011 (S.D.).
Paul
P
Kell
Department of Energy Great Lakes Bioenergy Research Center (R.S.S., M.W.B., N.d.L., S.M.K.), Department of Agronomy (R.S.S., M.W.B., P.K., N.d.L., S.M.K.), and Department of Botany (E.P.S.), University of Wisconsin, Madison, Wisconsin 53706;Department of Agronomy and Plant Genetics, University of Minnesota, St. Paul, Minnesota 55108 (C.N.H.);Department of Energy Great Lakes Bioenergy Research Center (K.L.C., C.R.B.) and Department of Plant Biology (K.L.C., C.R.B.), Michigan State University, East Lansing, Michigan 48824; andUnited States Department of Agriculture-Agricultural Research Service, Corn Insects and Crop Genetics Research Unit, Ames, Iowa 50011 (S.D.).
Susan
S
Duvick
Department of Energy Great Lakes Bioenergy Research Center (R.S.S., M.W.B., N.d.L., S.M.K.), Department of Agronomy (R.S.S., M.W.B., P.K., N.d.L., S.M.K.), and Department of Botany (E.P.S.), University of Wisconsin, Madison, Wisconsin 53706;Department of Agronomy and Plant Genetics, University of Minnesota, St. Paul, Minnesota 55108 (C.N.H.);Department of Energy Great Lakes Bioenergy Research Center (K.L.C., C.R.B.) and Department of Plant Biology (K.L.C., C.R.B.), Michigan State University, East Lansing, Michigan 48824; andUnited States Department of Agriculture-Agricultural Research Service, Corn Insects and Crop Genetics Research Unit, Ames, Iowa 50011 (S.D.).
Edgar P
EP
Spalding
Department of Energy Great Lakes Bioenergy Research Center (R.S.S., M.W.B., N.d.L., S.M.K.), Department of Agronomy (R.S.S., M.W.B., P.K., N.d.L., S.M.K.), and Department of Botany (E.P.S.), University of Wisconsin, Madison, Wisconsin 53706;Department of Agronomy and Plant Genetics, University of Minnesota, St. Paul, Minnesota 55108 (C.N.H.);Department of Energy Great Lakes Bioenergy Research Center (K.L.C., C.R.B.) and Department of Plant Biology (K.L.C., C.R.B.), Michigan State University, East Lansing, Michigan 48824; andUnited States Department of Agriculture-Agricultural Research Service, Corn Insects and Crop Genetics Research Unit, Ames, Iowa 50011 (S.D.).
C Robin
CR
Buell
Department of Energy Great Lakes Bioenergy Research Center (R.S.S., M.W.B., N.d.L., S.M.K.), Department of Agronomy (R.S.S., M.W.B., P.K., N.d.L., S.M.K.), and Department of Botany (E.P.S.), University of Wisconsin, Madison, Wisconsin 53706;Department of Agronomy and Plant Genetics, University of Minnesota, St. Paul, Minnesota 55108 (C.N.H.);Department of Energy Great Lakes Bioenergy Research Center (K.L.C., C.R.B.) and Department of Plant Biology (K.L.C., C.R.B.), Michigan State University, East Lansing, Michigan 48824; andUnited States Department of Agriculture-Agricultural Research Service, Corn Insects and Crop Genetics Research Unit, Ames, Iowa 50011 (S.D.).
Natalia
N
de Leon
Department of Energy Great Lakes Bioenergy Research Center (R.S.S., M.W.B., N.d.L., S.M.K.), Department of Agronomy (R.S.S., M.W.B., P.K., N.d.L., S.M.K.), and Department of Botany (E.P.S.), University of Wisconsin, Madison, Wisconsin 53706;Department of Agronomy and Plant Genetics, University of Minnesota, St. Paul, Minnesota 55108 (C.N.H.);Department of Energy Great Lakes Bioenergy Research Center (K.L.C., C.R.B.) and Department of Plant Biology (K.L.C., C.R.B.), Michigan State University, East Lansing, Michigan 48824; andUnited States Department of Agriculture-Agricultural Research Service, Corn Insects and Crop Genetics Research Unit, Ames, Iowa 50011 (S.D.) smkaeppl@wisc.edu.
Shawn M
SM
Kaeppler