title: Wide variability in kernel composition, seed characteristics, and zein profiles among diverse maize inbreds, landraces, and teosinte.
abstract: All crop species have been domesticated from their wild relatives, and geneticists are just now beginning to understand the consequences of artificial (human) selection on agronomic traits that are relevant today. The primary consequence is a basal loss of diversity across the genome, and an additional reduction in diversity for genes underlying traits targeted by selection. An understanding of attributes of the wild relatives may provide insight into target traits and valuable allelic variants for modern agriculture. This is especially true for maize (Zea mays ssp. mays), where its wild ancestor, teosinte (Z. mays ssp. parviglumis), is so strikingly different than modern maize. One obvious target of selection is the size and composition of the kernel. We evaluated kernel characteristics, kernel composition, and zein profiles for a diverse set of modern inbred lines, teosinte accessions, and landraces, the intermediate between inbreds and teosinte. We found that teosinte has very small seeds, but twice the protein content of landraces and inbred lines. Teosinte has a higher average alpha zein content (nearly 89% of total zeins as compared to 72% for inbred lines and 76% for landraces), and there are many novel alcohol-soluble proteins in teosinte relative to the other two germplasm groups. Nearly every zein protein varied in abundance among the germplasm groups, especially the methionine-rich delta zein protein, and the gamma zeins. Teosinte and landraces harbor phenotypic variation that will facilitate genetic dissection of kernel traits and grain quality, ultimately leading to improvement via traditional plant breeding and/or genetic engineering.
authors.affiliation: USDA-ARS, Plant Genetics Research Unit, Columbia, MO 65211, USA. Sherry.Flint-Garcia@ars.usda.gov
authors.forename: Sherry A
authors.initials: SA
authors.lastname: Flint-Garcia
authors.forename: Anastasia L
authors.initials: AL
authors.lastname: Bodnar
authors.forename: M Paul
authors.initials: MP
authors.lastname: Scott
mesh_terms: D000383:Agriculture; D018556:Crops, Agricultural / Q000235:genetics*; D014644:Genetic Variation; D005843:Geography; D012639:Seeds / Q000235:genetics*; D012641:Selection, Genetic; D003313:Zea mays / Q000235:genetics*; D015028:Zein / Q000235:genetics*
chemical_list: D015028:Zein
references.citation: Science. 1993 Oct 8;262(5131):233-5
references.pmid: 17841871
references.citation: Science. 2005 May 27;308(5726):1310-4
references.pmid: 15919994
references.citation: Plant J. 1995 Sep;8(3):359-68
references.pmid: 7550374
references.citation: Genetics. 1998 Oct;150(2):899-909
references.pmid: 9755218
references.citation: Genome Res. 2001 Nov;11(11):1817-25
references.pmid: 11691845
references.citation: Annu Rev Genet. 2004;38:37-59
references.pmid: 15568971
references.citation: Theor Appl Genet. 2005 Apr;110(6):1061-7
references.pmid: 15754207
references.citation: Plant Mol Biol. 1992 Feb;18(4):827-33
references.pmid: 1558957
references.citation: Genetics. 1995 Sep;141(1):333-46
references.pmid: 8536981
references.citation: Nature. 1999 Mar 18;398(6724):236-9
references.pmid: 10094045
references.citation: J Agric Food Chem. 1980 Nov-Dec;28(6):1334-6
references.pmid: 7451765
references.citation: Proc Natl Acad Sci U S A. 2006 Nov 7;103(45):16666-71
references.pmid: 17068128
references.citation: Plant Biotechnol J. 2005 Nov;3(6):555-69
references.pmid: 17147627
references.citation: Proc Natl Acad Sci U S A. 2002 Oct 1;99(20):12959-62
references.pmid: 12244216
references.citation: Bioessays. 1989 Apr;10(4):108-13
references.pmid: 2658986
references.citation: J Agric Food Chem. 2004 Apr 7;52(7):1958-64
references.pmid: 15053536
references.citation: Genetics. 2007 Nov;177(3):1915-28
references.pmid: 17947434
references.citation: Proc Natl Acad Sci U S A. 2003 Jul 22;100(15):9055-60
references.pmid: 12853580
references.citation: PLoS Genet. 2006 Nov 17;2(11):e199
references.pmid: 17112320
references.citation: Plant Physiol. 2002 Dec;130(4):1626-35
references.pmid: 12481046
references.citation: Genetics. 2006 Jun;173(2):953-64
references.pmid: 16547110
references.citation: Genetics. 2008 Jan;178(1):539-51
references.pmid: 18202393
references.citation: Science. 2009 Aug 7;325(5941):714-8
references.pmid: 19661422
references.citation: Genetics. 2008 Apr;178(4):2433-7
references.pmid: 18430961
references.citation: Plant Cell. 1996 Dec;8(12):2335-45
references.pmid: 8989886
references.citation: Plant Physiol. 1991 Mar;95(3):777-86
references.pmid: 16668053
references.citation: Science. 2009 Aug 7;325(5941):737-40
references.pmid: 19661427
references.citation: Proc Natl Acad Sci U S A. 2004 Jan 20;101(3):700-7
references.pmid: 14701910
references.citation: Plant Cell. 2001 Oct;13(10):2297-317
references.pmid: 11595803
references.citation: Proc Natl Acad Sci U S A. 2002 Apr 30;99(9):6080-4
references.pmid: 11983901
references.citation: Plant J. 2002 May;30(4):395-402
references.pmid: 12028570
references.citation: J Mol Evol. 1984;20(3-4):330-40
references.pmid: 6439887
references.citation: Plant Cell. 2005 Nov;17(11):2859-72
references.pmid: 16227451