A5015556712- Plant Molecular Biology Research
- Plant Reproductive Biology
- Chromosomal and Genetic Variations
- Genetic Mapping and Diversity in Plants and Animals
- Plant nutrient uptake and metabolism
- Plant Virus Research Studies
- CRISPR and Genetic Engineering
- Plant Disease Resistance and Genetics
- Plant tissue culture and regeneration
- Genomics and Phylogenetic Studies
- Plant Stress Responses and Tolerance
- Plant Gene Expression Analysis
- Bioenergy crop production and management
- Animal Genetics and Reproduction
- Plant Pathogens and Fungal Diseases
- Genomics and Rare Diseases
- Cancer Research and Treatments
- Plant and animal studies
- RNA and protein synthesis mechanisms
- Legume Nitrogen Fixing Symbiosis
- Molecular Biology Techniques and Applications
- Plant Genetic and Mutation Studies
- graph theory and CDMA systems
- Photosynthetic Processes and Mechanisms
- Microbial bioremediation and biosurfactants
Iowa State University
2013-2025
Cold Spring Harbor Laboratory
2000-2005
Agricultural Research Service
1991-2005
Syngenta (United States)
2003
University of California, Berkeley
1994-2000
Technische Universität Braunschweig
1998
Plant Gene Expression Center
1989-1994
United States Department of Agriculture
1990
Abstract Genetic control of grass inflorescence architecture is critical given that cereal seeds provide most the world's food. Seeds are borne on axillary branches, which arise from groups stem cells in axils leaves and whose branching patterns dictate variation plant form. Normal maize (Zea mays) ears unbranched, tassels have long branches only at their base. The ramosa2 (ra2) mutant has increased with short replaced by long, indeterminate ones. ra2 was cloned chromosome walking shown to...
The maize W22 inbred has served as a platform for genetics since the mid twentieth century. To streamline genome analyses, we have sequenced and de novo assembled reference using short-read sequencing technologies. We show that significant structural heterogeneity exists in comparison to B73 at multiple scales, from transposon composition copy number variation single-nucleotide polymorphisms. generation of this enables accurate placement thousands Mutator (Mu) Dissociation (Ds) transposable...
The homeobox of the knotted1 (kn1) gene was used to isolate 12 related sequences in maize. homeodomains encoded by kn1-like genes are very similar, ranging from 55 89% amino acid identity. Differences outside precisely conserved third helix allowed us group into two classes. seven class 1 share 73 identical residues with kn1. four 2 58% kn1, although conservation within is greater than 87%. Expression patterns were analyzed RNA gel blot analysis. Class highly expressed meristem-enriched...
ABSTRACT The knotted1 (kn1) gene of maize is expressed in meristems and absent from leaves, including the site leaf initiation within meristem. Recessive mutations kn1 have been described that limit capacity to make branches result extra carpels. Dominant suggest function plays a role maintaining cells an undifferentiated state. We took advantage Ds-induced dominant allele order screen for additional recessive alleles resulting mobilization Ds element. Analysis one such revealed novel...
Development in higher plants depends on the activity of meristems, formative regions that continuously initiate new organs at their flanks. Meristems must maintain a balance between stem cell renewal and organ initiation. In fasciated mutants, initiation fails to keep pace with meristem proliferation. The thick tassel dwarf1 (td1) mutation maize affects both male female inflorescence development. inflorescence, which results ear, is fasciated, extra rows kernels. or tassel, shows an increase...
Plant axillary meristems are composed of highly organized, self-renewing stem cells that produce indeterminate branches or terminate in differentiated structures, such as the flowers. These opposite fates, dictated by both genetic and environmental factors, determine interspecific differences architecture plants. The Cys(2)-His(2) zinc-finger transcription factor RAMOSA1 (RA1) regulates fate most during early development maize inflorescences, tassel ear, has been implicated evolution grass...
Genetic control of branching is a primary determinant yield, regulating seed number and harvesting ability, yet little known about the molecular networks that shape grain-bearing inflorescences cereal crops. Here, we used maize ( Zea mays ) inflorescence to investigate gene modulate determinacy, specifically decision allow branch growth. We characterized developmental transitions by associating spatiotemporal expression profiles with morphological changes resulting from genetic perturbations...
Plant architecture is dictated by precise control of meristematic activity. In the shoot, an imbalance in positive or negative maintenance signals can result a fasciated enlarged meristem phenotype. ear4 (fea4) semidwarfed mutant with ears and tassels as well greatly vegetative inflorescence meristems. We identified FEA4 bZIP transcription factor, orthologous to Arabidopsis thaliana PERIANTHIA. was expressed peripheral zone shoot apical vasculature immature leaves conspicuously excluded from...
Leaf architecture directly influences canopy structure, consequentially affecting yield. We discovered a maize (Zea mays) mutant with aberrant leaf architecture, which we named drooping leaf1 (drl1). Pleiotropic mutations in drl1 affect length and width, angle, internode diameter. These phenotypes are enhanced by natural variation at the drl2 enhancer locus, including reduced expression of drl2-Mo17 allele Mo17 inbred. A second allele, produced transposon mutagenesis, interacted...
The maize (Zea mays) transposable element Dissociation (Ds) was mobilized for large-scale genome mutagenesis and to study its endogenous biology. Starting from a single donor locus on chromosome 10, over 1500 elements were distributed throughout the positioned physical map. Genetic strategies enrich both local unlinked insertions used distribute Ds insertions. Global, regional, insertion site trends examined. We show that transposed linked sites displayed nonuniform distribution genetic map...
Summary Transcription activator‐like effector nuclease ( TALEN ) technology has been utilized widely for targeted gene mutagenesis, especially inactivation, in many organisms, including agriculturally important plants such as rice, wheat, tomato and barley. This report describes application of this to generate heritable genome modifications maize. s were employed stable, mutations at the maize g lossy2 gl2 locus. Transgenic lines containing mono‐ or di‐allelic obtained from genotype Hi‐ II a...
Axillary branch suppression is a favorable trait bred into many domesticated crop plants including maize compared with its highly branched wild ancestor teosinte. Branch in was achieved through selection of gain function allele the teosinte branched1 (tb1) transcription factor that acts as repressor axillary bud growth. Previous work indicated other loci may epistatically tb1 and be responsible for some phenotypic effects. Here, we show mediates direct activation tassels replace upper ears1...
Abstract Background Plant gametophytes play central roles in sexual reproduction. A hallmark of the plant life cycle is that gene expression required haploid gametophytes. Consequently, many mutant phenotypes are expressed this phase. Results We perform a quantitative RNA-seq analysis embryo sacs, comparator ovules with sacs removed, mature pollen, and seedlings to assist identification gametophyte functions maize. Expression levels were determined for annotated genes both gametophytes,...
Abstract The aleurone is the outermost layer of cereal endosperm and functions to digest storage products accumulated in starchy cells as well confer important dietary health benefits. Whereas normal maize (Zea mays [Zm]) has a single layer, naked (nkd) mutants produce multiple outer cell layers partially differentiated that show sporadic expression identity markers such viviparous1 promoter -β-glucuronidase transgene. 15:1 F2 segregation ratio suggested two recessive genes were involved,...
We describe an efficient system for site-selected transposon mutagenesis in maize. A total of 43,776 F 1 plants were generated by using Robertson's Mutator ( Mu ) pollen parents and self-pollinated to establish a library transposon-mutagenized seed. The frequency new seed mutants was between 10 –4 –5 per plant. As service the maize community, maize-targeted selects insertions genes interest from this PCR. Pedigree, knockout, sequence, phenotype, other information is stored powerful...
Modern maize was domesticated from Zea mays parviglumis, a teosinte, about 9000 years ago in Mexico. Genes thought to have been selected upon during the domestication of crops are commonly known as loci. The ramosa1 (ra1) gene encodes putative transcription factor that controls branching architecture tassel and ear. Previous work demonstrated reduced nucleotide diversity segment ra1 survey modern inbreds, indicating positive selection occurred at some point time since diverged its common...
Summary Type C cytoplasmic male sterility ( CMS ‐C) is the most commonly used form of in maize hybrid seed production. Restorer fertility 4 Rf4 ), major restorer gene ‐C, located on chromosome 8S. To positionally clone , a large F3 population derived from cross between non‐restorer and n = 5104) was screened for recombinants then phenotyped tassel fertility, resulting final map‐based cloning interval 12 kb. Within this 12‐kb interval, only likely candidate GRMZM 2G021276, basic...
In flowering plants, gene expression in the haploid male gametophyte (pollen) is essential for sperm delivery and double fertilization. Pollen also undergoes dynamic epigenetic regulation of from transposable elements (TEs), but how this process interacts with not clearly understood. To explore relationships among these processes, we quantified transcript levels four reproductive stages maize (tassel primordia, microspores, mature pollen, cells) via RNA-seq. We found that, contrast...
Large-scale sequencing of human cancer genomes and mouse transposon-induced tumors has identified a vast number genes mutated in different cancers. One the outstanding challenges this field is to determine which genes, when mutated, contribute cellular transformation tumor progression. To identify new conserved that drive tumorigenesis we have developed novel model distantly related vertebrate species, zebrafish, Danio rerio. The Sleeping Beauty (SB) T2/Onc transposon system was adapted for...
Floral morphology is shaped by factors that modulate floral meristem activity and size, the identity, number arrangement of lateral organs they form. We report maize CRABS CLAW co-orthologs drooping leaf1 (drl1) drl2 are required for development ear tassel florets. Pistillate florets drl1 ears sterile with unfused carpels fail to enclose an expanded nucellus-like structure. Staminate tassels have extra stamens fertile anthers. Natural variation transposon alleles enhance mutant phenotypes...
Maize (Zea mays L.) C-type cytoplasmic male sterility (CMS-C) is a highly used CMS system for maize commercial hybrid seed production. Rf4 the major dominant restorer gene CMS-C. Inbreds were recently discovered which contain restoring allele yet are unable to restore fertility due lack of an additional required Rf4's restoration. To find this gene, QTL mapping and positional cloning performed using inbred that contained but was incapable The mapped 738-kb interval on chromosome 2, contains...