Other Plant Sciences Commons^™

2011 Vadose Zone Nitrate Study At Hastings, Ne (Revised), Roy F. Spalding, Martin Toavs

Department of Agronomy and Horticulture: Faculty Publications

In an effort to assist Hastings Utilities in the management of their well-head protection area (WHP A) and to protect the groundwater from the impact of nitrate loading from potential nonpoint and point sources, Hastings Utilities subcontracted with the Department of Agronomy and Horticulture at the University of Nebraska for deep vadose zone coring. Continuous 60-ft soil cores were obtained at 36 sites within the apparent WHP A (Figure 1). The sites were selected by Marty Stange on the basis of availability for sampling, management, landuse , cropping history, and location within the WHPA. Nitrogen analyses of these deep soil …

Genome-Wide Analysis Of Syntenic Gene Deletion In The Grasses, James C. Schnable, Michael Freeling, Eric Lyons

Department of Agronomy and Horticulture: Faculty Publications

The grasses, Poaceae, are one of the largest and most successful angiosperm families. Like many radiations of flowering plants, the divergence of the major grass lineages was preceded by a whole-genome duplication (WGD), although these events are not rare for flowering plants. By combining identification of syntenic gene blocks with measures of gene pair divergence and different frequencies of ancient gene loss, we have separated the two subgenomes present in modern grasses. Reciprocal loss of duplicated genes or genomic regions has been hypothesized to reproductively isolate populations and, thus, speciation. However, in contrast to previous studies in yeast and teleost …

Brown Midrib2 (Bmr2) Encodes The Major 4-Coumarate: Coenzyme A Ligase Involved In Lignin Biosynthesis In Sorghum (Sorghum Bicolor (L.) Moench), Ana Saballos, Scott Sattler, Emiliano Sanchez, Timothy P. Foster, Zhanguo Xin, Chulhee Kang, Jeffrey F. Pedersen, Wilfred Vermerris

Department of Agronomy and Horticulture: Faculty Publications

Successful modification of plant cell-wall composition without compromising plant integrity is dependent on being able to modify the expression of specific genes, but this can be very challenging when the target genes are members of multigene families. 4-coumarate:CoA ligase (4CL) catalyzes the formation of 4-coumaroyl CoA, a precursor of both flavonoids and monolignols, and is an attractive target for transgenic down-regulation aimed at improving agro-industrial properties. Inconsistent phenotypes of transgenic plants have been attributed to variable levels of down-regulation of multiple 4CL genes. Phylogenetic analysis of the sorghum genome revealed 24 4CL(-like) proteins, five of which cluster with bona fide …

Quantitative Trait Locus Analysis Of Saturated Fatty Acids In A Population Of Recombinant Inbred Lines Of Soybean, Xianzhi Wang, Guo-Liang Jiang, Marci Green, Roy A. Scott, D. L. Hyten, P. B. Cregan

Department of Agronomy and Horticulture: Faculty Publications

Soybean [Glycine max (L.) Merr.] is an important crop which contributes approximately 58% of the world’s oilseed production. Palmitic and stearic acids are the two main saturated fatty acids in soybean oil. Different levels of saturated fatty acids are desired depending on the uses of the soybean oil. Vegetable oil low in saturated fatty acids is preferred for human consumption, while for industrial applications, soybean oil with higher levels of saturated fatty acids is more suitable. The objectives of this study were to identify quantitative trait loci (QTL) for saturated fatty acids, analyze the genetic effects of single QTL …

Natural Variation In Iron Use Efficiency And Mineral Remobilization In Cucumber (Cucumis Sativus), Brian M. Waters, Grace Troupe

Department of Agronomy and Horticulture: Faculty Publications

Aims: Iron (Fe) is an essential micronutrient, and plant-available Fe is often limited in alkaline soils. Fe deficiency chlorosis decreases plant growth and yield. Identification of germplasm with high and low Fe use efficiency will allow studies to better understand the genetic components for breeding Fe efficient varieties.

Methods: A screen using cucumber (Cucumis sativus) seedlings identified varieties that maintained contrasting levels of chlorophyll under Fe deficiency or limitation. A time course of mineral dynamics in cotyledons was conducted.

Results: The variety Ashley had the highest chlorophyll under Fe deficiency and per unit Fe in the leaf, while …

Greenhouse Production Of Strawberries During The Winter, Ellen T. Paparozzi, George E. Meyer, Stacy A. Adams, M. Elizabeth Conley, Benjamin A. Loseke, Paul E. Read

Department of Agronomy and Horticulture: Faculty Publications

Strawberries are one of America’s favorite fruits and are available in grocery stores year round. Given increased shipping and other associated costs as well as the opportunity to provide a fresh, nutritious, local product, our research team is exploring the feasibility of growing strawberries during the winter in Nebraska.

Productivity Of Field Pea (Pisumsativum L.) And Spring Oat (Avena Sativa L.) Grown As Sole And Intercrops Under Different Nitrogen Levels, Chengchou Han, Christopher Borman, Dori Osantowski, Jeremy Wagnitz, Katja Koehler-Cole, Kevin Korus, Evan Sonderegger, Rodrigo Werle, Tara Wood, John L. Lindquist

Department of Agronomy and Horticulture: Faculty Publications

Intercropping cereal grains and legumes has potential as an alternative cool-season forage crop in low-input farming systems. The objectives of this study were to quantify the effects of density, species proportion, and nitrogen (N) supply on the biomass accumulation of field pea and spring oat grown as sole or intercrops. Greenhouse experiments were conducted using an additive series experimental design. Treatments included three fertilizer N rates and 20 density/proportion combinations in a randomized complete block with four replications. Sole plant densities included 2, 3, 4, 5 plants of each species pot-1 (16 cm in diameter, 16 cm in height). The …

Inheritance Of Grain Polyphenol Oxidase (Ppo) Activity In Multiple Wheat (Triticum Aestivum L.) Genetic Backgrounds, Somrudee Nilthong, Robert A. Graybosch, P. Stephen Baenziger

Department of Agronomy and Horticulture: Faculty Publications

Grain polyphenol oxidase (PPO) activity can cause discoloration of wheat (Triticum aestivum L.) food products. Five crosses (PI 117635/Antelope; Fielder/ NW03681; Fielder/Antelope; NW07OR1070/Antelope; NW07OR1066/OR2050272H) were selected to study the genetic inheritance of PPO activity. STS markers, PPO18, PPO29 and STS01, were used to identify lines with putative alleles at the Ppo-A1 and Ppo-D1 loci conditioning low or high PPO activity. ANOVA showed significant genotypic effects on PPO activity (P\0.0001) in all populations. The generations and generation 9 genotype effects were not significant in any population. A putative third (null) genotype at Ppo-A1 (no PCR fragments for PPO18) was discovered …

Identification And Characterization Of Four Missense Mutations In Brown Midrib 12 (Bmr12), The Caffeic O-Methyltranferase (Comt) Of Sorghum, Scott E. Sattler, Nathan A. Palmer, Ana Saballos, Ann M. Greene, Zhanguo Xin, Gautam Sarath, Wilfred Vermerris, Jeffrey F. Pedersen

Department of Agronomy and Horticulture: Faculty Publications

Modifying lignin content and composition are targets to improve bioenergy crops for cellulosic conversion to biofuels. In sorghum and other C4 grasses, the brown midrib mutants have been shown to reduce lignin content and alter its composition. Bmr12 encodes the sorghum caffeic O-methyltransferase, which catalyzes the penultimate step in monolignol biosynthesis. From an EMS-mutagenized TILLING population, four bmr12 mutants were isolated. DNA sequencing identified the four missense mutations in the Bmr12 coding region, which changed evolutionarily conserved amino acids Ala71Val, Pro150Leu, Gly225Asp, and Gly325Ser. The previously characterized bmr12 mutants all contain premature stop codons. These newly identified mutants, along …

Cultivating A Movement: Excerpts From An Oral History Of Organic Farming And Sustainable Agriculture On California’S Central Coast [Book Review], Charles A. Francis

Department of Agronomy and Horticulture: Faculty Publications

Edited by I. Reti and S. Rabkin, 2011. University of California, Santa Cruz, Library, Santa Cruz, California, United States. 299 p., US$19.95, ISBN 9-780972-33431, paper.

Often the most compelling evidence for success of organic farming comes from the personal stories of farmers. Coupled with reports on the application of science in organics, the practical knowledge of people in the field provides a rich foundation for the ongoing growth of this intriguing sector of the food system. This collection of interviews by the staff of the Regional History Project is one unique activity of the University of California, Santa Cruz library, …

Estimating Construction Costs For A Low-Cost Quonset-Style Greenhouse, David P. Lambe, Stacy A. Adams, Ellen T. Paparozzi

Department of Agronomy and Horticulture: Faculty Publications

Double polyethylene Quonset-style greenhouses offergrowers and farmers a more cost-effective structure than glass- or acrylic-covered structures for growing plants off-season. These greenhouses are especially applicablefor producing off-season high value crops such as fruits and vegetables for local markets. To support this production alternative, this publication contains a list of greenhouse components, the start-up costs associated with these items and an estimate of the number of person hours required to assemble and outfit a 24-foot-by-72-foot double polyethylene, air-inflated greenhouse structure. As there are many options available for building double polyethylene greenhouses, the main purpose of this publication is to identify the …

The ‘Pi 438489b’ By ‘Hamilton’ Snp-Based Genetic Linkage Map Of Soybean [Glycine Max (L.) Merr.] Identified Quantitative Trait Loci That Underlie Seedling Sds Resistance, Kassem My Abdelmajid, Laura Ramos, Leonor Leandro, Gladys Mbofung, D. L. Hyten, Stella K. Kantartzi, Robert L. Grier Iv, Victor N. Njiti, Khalid Meksem

Department of Agronomy and Horticulture: Faculty Publications

Soybeans [Glycine max (L.) Merr.] are susceptible to many diseases including fungal diseases such as soybean sudden death syndrome (SDS). Several studies reported SDS resistance quantitative trait loci (QTL) on the soybean genome using different recombinant inbred line (RIL) populations and low density genetic linkage maps. High density exclusively single nucleotide polymorphisms-based (SNP-based) maps were not yet reported in soybean. The objectives of this study were (1) to construct a high density SNP-based genetic linkage map of soybean using the ‘PI438489B’ by ‘Hamilton’ (PIxH, n=50) recombinant inbred line population, and (2) to map QTL for SDS resistance using this …

Structural Variants In The Soybean Genome Localize To Clusters Of Biotic Stress-Response Genes, Leah K. Mchale, William J. Haun, Wayne W. Xu, Pudota B. Bhaskar, Justin E. Anderson, D. L. Hyten, Daniel J. Gerhardt, Jeffrey A. Jeddeloh, Robert M. Stupar

Department of Agronomy and Horticulture: Faculty Publications

Genome-wide structural and gene content variations are hypothesized to drive important phenotypic variation within a species. Structural and gene content variations were assessed among four soybean (Glycine max) genotypes using array hybridization and targeted resequencing. Many chromosomes exhibited relatively low rates of structural variation (SV) among genotypes. However, several regions exhibited both copy number and presence-absence variation, the most prominent found on chromosomes 3, 6, 7, 16, and 18. Interestingly, the regions most enriched for SV were specifically localized to gene-rich regions that harbor clustered multigene families. The most abundant classes of gene families associated with these regions …

Identification Of Positive Yield Qtl Alleles From Exotic Soybean Germplasm In Two Backcross Populations, K.-S. Kim, B. W. Diers, D. L. Hyten, M. A. Rouf Mian, J. G. Shannon, R. L. Nelson

Department of Agronomy and Horticulture: Faculty Publications

Increasing seed yield is an important breeding goal of soybean [Glycine max (L.) Merr.] improvement efforts. Due to the small number of ancestors and subsequent breeding and selection, the genetic base of current soybean cultivars in North America is narrow. The objective of this study was to map quantitative trait loci (QTL) in two backcross populations developed using soybean plant introductions as donor parents. The first population included 116 BC₂F₃-derived lines developed using ‘‘Elgin’’ as the recurrent parent and PI 436684 as the donor parent (E population). The second population included 93 BC₃F …

Molecular Mapping Of Soybean Rust Resistance In Soybean Accession Pi 561356 And Snp Haplotype Analysis Of The Rpp1 Region In Diverse Germplasm, Ki-Seung Kim, Jair R. Unfried, D. L. Hyten, Reid D. Frederick, Glen L. Hartman, Randall L. Nelson, Qijian Song, Brian W. Diers

Department of Agronomy and Horticulture: Faculty Publications

Soybean rust (SBR), caused by Phakopsora pachyrhizi Sydow, is one of the most economically important and destructive diseases of soybean [Glycine max (L.) Merr.] and the discovery of novel SBR resistance genes is needed because of virulence diversity in the pathogen. The objectives of this research were to map SBR resistance in plant introduction (PI) 561356 and to identify single nucleotide polymorphism (SNP) haplotypes within the region on soybean chromosome 18 where the SBR resistance gene Rpp1 maps. One-hundred F_2:3 lines derived from a cross between PI 561356 and the susceptible experimental line LD02-4485 were genotyped with genetic …

Advances In Genome Sequencing And Genotyping Technology For Soybean Diversity Analysis, David L. Hyten

Department of Agronomy and Horticulture: Faculty Publications

The completion of a soybean draft whole genome sequence along with advances in sequencing and genotyping technologies are creating a revolution in soybean genomics. The draft whole genome sequence of soybean is allowing researchers to fully take advantage of this new technology and is rapidly changing how soybean germ plasm is mined. Genetic markers such as SNPs can be quickly identified by using next generation sequencing and assayed on a large number of materials using advanced technologies that can genotype tens of thousands of markers on thousands of individuals very rapidly. This ability to qUickly identify and genotype genetic diversity …

High-Resolution Mapping Of Open Chromatin In The Rice Genome, Wenli Zhang, Yufeng Wu, James C. Schnable, Zixian Zeng, Michael Freeling, Gregory E. Crawford, Jiming Jiang

Department of Agronomy and Horticulture: Faculty Publications

Gene expression is controlled by the complex interaction of transcription factors binding to promoters and other regulatory DNA elements. One common characteristic of the genomic regions associated with regulatory proteins is a pronounced sensitivity to DNase I digestion. We generated genome-wide high-resolution maps of DNase I hypersensitive (DH) sites from both seedling and callus tissues of rice (Oryza sativa). Approximately 25% of the DH sites from both tissues were found in putative promoters, indicating that the vast majority of the gene regulatory elements in rice are not located in promoter regions. We found 58% more DH sites in …

Heritable Epigenetic Variation Among Maize Inbreds, Steve R. Eichten, Ruth A. Swanson, James C. Schnable, Amanda J. Waters, Peter J. Hermanson, Sanzhen Liu, Cheng-Ting Yeh, Yi Jia, Karla Gendler, Michael Freeling, Patrick S. Schnable, Matthew W. Vaughn, Nathan M. Springer

Department of Agronomy and Horticulture: Faculty Publications

Epigenetic variation describes heritable differences that are not attributable to changes in DNA sequence. There is the potential for pure epigenetic variation that occurs in the absence of any genetic change or for more complex situations that involve both genetic and epigenetic differences. Methylation of cytosine residues provides one mechanism for the inheritance of epigenetic information. A genome-wide profiling of DNA methylation in two different genotypes of Zea mays (ssp. mays), an organism with a complex genome of interspersed genes and repetitive elements, allowed the identification and characterization of examples of natural epigenetic variation. The distribution of DNA methylation …

Miscanthus 3 Giganteus Productivity: The Effects Of Management In Different Environments, Matt Maughan, German Bollero, D.K. Lee, Robert Darmody, Stacy Bonos, Laura Cortese, James Murphy, Roch E. Gaussoin, Matthew Sousek, David Williams, Linda Williams, Fernando Miguez, Thomas Voigt

Department of Agronomy and Horticulture: Faculty Publications

Miscanthus 9 giganteus is a C4 perennial grass that shows great potential as a high-yielding biomass crop. Scant research has been published that reports M. 9 giganteus growth and biomass yields in different environments in the United States. This study investigated the establishment success, plant growth, and dry biomass yield of M. 9 giganteus during its first three seasons at four locations (Urbana, IL; Lexington, KY; Mead, NE; Adelphia, NJ) in the United States. Three nitrogen rates (0, 60, and 120 kg ha -1) were applied at each location each year. Good survival of M. 9 giganteus during its first …

Screening Synteny Blocks In Pairwise Genome Comparisons Through Integer Programming, Haibao Tang, Eric Lyons, Brent S. Pedersen, James C. Schnable, Andrew H. Paterson, Michael Freeling

Department of Agronomy and Horticulture: Faculty Publications

Background:

It is difficult to accurately interpret chromosomal correspondences such as true orthology and paralogy due to significant divergence of genomes from a common ancestor. Analyses are particularly problematic among lineages that have repeatedly experienced whole genome duplication (WGD) events. To compare multiple “subgenomes” derived from genome duplications, we need to relax the traditional requirements of “one-to-one” syntenic matchings of genomic regions in order to reflect “one-to-many” or more generally “many-to-many” matchings. However this relaxation may result in the identification of synteny blocks that are derived from ancient shared WGDs that are not of interest. For many downstream analyses, we …

A First Insight Into Population Structure And Linkage Disequilibrium In The U.S. Peanut Minicore Collection, Vikas Belamkar, Michael Gomez Selvaraj, Jamie L. Ayers, Paxton R. Payton, Naveen Puppala, Mark D. Burow

Department of Agronomy and Horticulture: Faculty Publications

Knowledge of genetic diversity, population structure, and degree of linkage disequilibrium (LD) in target association mapping populations is of great importance and is a prerequisite for LD-based mapping. In the present study, 96 genotypes comprising 92 accessions of the US peanut minicore collection, a component line of the tetraploid variety Florunner, diploid progenitors A. duranensis (AA) and A. ipaënsis (BB), and synthetic amphidiploid accession TxAG-6 were investigated with 392 simple sequence repeat (SSR) marker bands amplified using 32 highly-polymorphic SSR primer pairs. Both distance- and model-based (Bayesian) cluster analysis revealed the presence of structured diversity. In general, the wild-species accessions …

Genes Identified By Visible Mutant Phenotypes Show Increased Bias Toward One Of Two Subgenomes Of Maize, James C. Schnable, Michael Freeling

Department of Agronomy and Horticulture: Faculty Publications

Not all genes are created equal. Despite being supported by sequence conservation and expression data, knockout homozygotes of many genes show no visible effects, at least under laboratory conditions. We have identified a set of maize (Zea mays L.) genes which have been the subject of a disproportionate share of publications recorded at MaizeGDB. We manually anchored these ‘‘classical’’ maize genes to gene models in the B73 reference genome, and identified syntenic orthologs in other grass genomes. In addition to proofing the most recent version 2 maize gene models, we show that a subset of these genes, those that …

Dose–Sensitivity, Conserved Non-Coding Sequences, And Duplicate Gene Retention Through Multiple Tetraploidies In The Grasses, James C. Schnable, Brent S. Pedersen, Sabarinath Subramaniam, Michael Freeling

Department of Agronomy and Horticulture: Faculty Publications

Whole genome duplications, or tetraploidies, are an important source of increased gene content. Following whole genome duplication, duplicate copies of many genes are lost from the genome. This loss of genes is biased both in the classes of genes deleted and the subgenome from which they are lost. Many or all classes are genes preferentially retained as duplicate copies are engaged in dose sensitive protein–protein interactions, such that deletion of any one duplicate upsets the status quo of subunit concentrations, and presumably lowers fitness as a result. Transcription factors are also preferentially retained following every whole genome duplications studied. This …

Switchgrass, Kenneth P. Vogel, Gautam Sarath, Aaron J. Saathoff, Robert B. Mitchell

Department of Agronomy and Horticulture: Faculty Publications

17.1 Introduction

Switchgrass (Panicum virgatum L.) is a warm-season perennial grass that is native to North America that is being developed into a biomass energy crop. It has been used in pastures and for conservation purposes in the Great Plains and the Midwest, USA, for over 70 years.1 The research supporting its use as a pasture and conservation species was largely conducted by US Department of Agriculture (USDA) research programs, most notably the Agricultural Research Service (ARS) project located at the University of Nebraska-Lincoln and USDA Plant Materials Centers that are located throughout the United States. In this report, …

Identification Of A Second Asian Soybean Rust Resistance Gene In Hyuuga Soybean, Mandy D. Kendrick, Donna K. Harris, Bo-Keun Ha, D. L. Hyten, P. B. Cregan, Reid D. Frederick, H. Roger Boerma, Kerry F. Pedley

Department of Agronomy and Horticulture: Faculty Publications

Asian soybean rust (ASR) is an economically significant disease caused by the fungus Phakopsora pachyrhizi. The soybean genes Rpp3 and Rpp?(Hyuuga) confer resistance to specific isolates of the pathogen. Both genes map to chromosome 6 (Gm06) (linkage group [LG] C2). We recently identified 12 additional soybean accessions that harbor ASR resistance mapping to Gm06, within 5 centimorgans of Rpp3 and Rpp?(Hyuuga). To further characterize genotypes with resistance on Gm06, we used a set of eight P. pachyrhizi isolates collected from geographically diverse areas to inoculate plants and evaluate them for differential phenotypic responses. …

Mutational Analysis Of The Major Soybean Uref Paralogue Involved In Urease Activation, Joe C. Polacco, D. L. Hyten, Mônica Medeiros-Silva, David A. Sleper, Kristin D. Bilyeu

Department of Agronomy and Horticulture: Faculty Publications

The soybean genome duplicated ~14 and 45 million years ago and has many paralogous genes, including those in urease activation (emplacement of Ni and CO₂ in the active site). Activation requires the UreD and UreF proteins, each encoded by two paralogues. UreG, a third essential activation protein, is encoded by the single-copy Eu3, and eu3 mutants lack activity of both urease isozymes. eu2 has the same urease-negative phenotype, consistent with Eu2 being a single-copy gene, possibly encoding a Ni carrier. Unexpectedly, two eu2 alleles co-segregated with missense mutations in the chromosome 2 UreF paralogue (Ch02UreF), suggesting …

Cytokinin-Mediated Source ⁄Sink Modifications Improve Drought Tolerance And Increase Grain Yield In Rice Under Water-Stress, Zvi Peleg, Maria Reguera, Ellen Tumimbang, Harkamal Walia, Eduardo Blumwald

Department of Agronomy and Horticulture: Faculty Publications

Drought is the major environmental factor limiting crop productivity worldwide. We hypothesized that it is possible to enhance drought tolerance by delaying stress-induced senescence through the stress-induced synthesis of cytokinins in crop-plants. We generated transgenic rice (Oryza sativa) plants expressing an isopentenyltransferase (IPT) gene driven by PSARK, a stress- and maturation-induced promoter. Plants were tested for drought tolerance at two yield-sensitive developmental stages: pre- and post-anthesis. Under both treatments, the transgenic rice plants exhibited delayed response to stress with significantly higher grain yield (GY) when compared to wild-type plants. Gene expression analysis revealed a significant shift in expression of hormone-associated …

Estimation Of Surface Soil Organic Matter Using A Ground-Based Active Sensor And Aerial Imagery, D. F. Roberts, V. I. Adamchuk, J. F. Shanahan, R. B. Ferguson, J. S. Schepers

Department of Agronomy and Horticulture: Faculty Publications

Active canopy sensors are currently being studied as a tool to assess crop N status and direct in-season N applications. The objective of this study was to use a variety of strategies to evaluate the capability of an active sensor and a wide-band aerial image to estimate surface soil organic matter (OM). Grid soil samples, active sensor reflectance and bare soil aerial images were obtained from six fields in central Nebraska before the 2007 and 2008 growing seasons. Six different strategies to predict OM were developed and tested by dividing samples randomly into calibration and validation datasets. Strategies included uniform, …

Stacking Resistance Alleles From Wild And Domestic Soybean Sources Improves Soybean Cyst Nematode Resistance, Myungsik Kim, D. L. Hyten, Terry L. Niblack, Brian W. Diers

Department of Agronomy and Horticulture: Faculty Publications

The soybean cyst nematode (SCN; Heterodera glycines Ichinohe) is the most economically important soybean [Glycine max (L.) Merr.] pathogen in the United States. Field SCN populations are adapting to the narrowly based SCN resistance currently deployed in soybean cultivars. The objective of our research was to measure the effects of combinations of SCN resistance genes or quantitative trait loci (QTL) from the wild soybean (Glycine soja Siebold & Zucc.) PI 468916 and the domesticated soybean accessions PI 88788 and PI 437654. Two populations were developed to test the combinations of QTL and genes. Both populations segregated for the …

Moving Micronutrients From The Soil To The Seeds: Genes And Physiological Processes From A Biofortification Perspective, Brian M. Waters, Renuka P. Sankaran

Department of Agronomy and Horticulture: Faculty Publications

The micronutrients iron (Fe), zinc (Zn), and copper (Cu) are essential for plants and the humans and animals that consume plants. Increasing the micronutrient density of staple crops, or biofortification, will greatly improve human nutrition on a global scale. This review discusses the processes and genes needed to translocate micronutrients through the plant to the developing seeds, and potential strategies for developing biofortified crops.