Plant Biology Commons^™

Adaptive Capacity In Ecosystems, David G. Angeler, Hannah Fried-Petersen, Craig R. Allen, Ahjond Garmestani, Dirac L. Twidwell Jr, H.E. Birgé, W. Chuang, V. M. Donovan, T. Eason, C.P. Roberts, S.M. Sundstrom, C.L. Wonkka

Department of Agronomy and Horticulture: Faculty Publications

Understanding the adaptive capacity of ecosystems to cope with change is crucial to management. However, unclear and often confusing definitions of adaptive capacity make application of this concept difficult. In this paper, we revisit definitions of adaptive capacity and operationalize the concept. We define adaptive capacity as the latent potential of an ecosystem to alter resilience in response to change. We present testable hypotheses to evaluate complementary attributes of adaptive capacity that may help further clarify the components and relevance of the concept. Adaptive sampling, inference and modeling can reduce key uncertainties incrementally over time and increase learning about adaptive …

Soybean Nodule-Associated Non-Rhizobial Bacteria Inhibit Plant Pathogens And Induce Growth Promotion In Tomato, Serkan Tokgöz, Dilip K. Lakshman, Mahmoud H. Ghozlan, Hasan Pinar, Daniel P. Roberts, Amitava Mitra

Department of Plant Pathology: Faculty Publications

The root nodules are a unique environment formed on legume roots through a highly specific symbiotic relationship between leguminous plants and nodule-inducing bacteria. Previously, Rhizobia were presumed to be the only group of bacteria residing within nodules. However, recent studies discovered diverse groups of bacteria within the legume nodules. In this report soybean nodule-associated bacteria were studied in an effort to identify beneficial bacteria for plant disease control and growth promotion. Analysis of surface-sterilized single nodules showed bacterial diversity of the nodule microbiome. Five hundred non-rhizobial colonies from 10 nodules, 50 colonies per nodule, were tested individually against the tomato …

Characterization Of The Transcriptional Divergence Between The Subspecies Of Cultivated Rice (Oryza Sativa), Malachy T. Campbell, Qian Du, Kan Li, Sandeep Sharma, Chi Zhang, Harkamal Walia

Agronomy & Horticulture -- Faculty Publications

Background: Cultivated rice consists of two subspecies, Indica and Japonica, that exhibit well-characterized differences at the morphological and genetic levels. However, the differences between these subspecies at the transcriptome level remains largely unexamined. Here, we provide a comprehensive characterization of transcriptome divergence and cis-regulatory variation within rice using transcriptome data from 91 accessions from a rice diversity panel (RDP1).

Results: The transcriptomes of the two subspecies of rice are highly divergent. Japonica have significantly lower expression and genetic diversity relative to Indica, which is likely a consequence of a population bottleneck during Japonica domestication. We leveraged high-density genotypic data and …

Semantic Segmentation Of Sorghum Using Hyperspectral Data Identifies Genetic Associations, Chenyong Miao, Alejandro Pages, Zheng Xu, Eric Rodene, Jinliang Yang, James C. Schnable

Center for Plant Science Innovation: Faculty Publications

This study describes the evaluation of a range of approaches to semantic segmentation of hyperspectral images of sorghum plants, classifying each pixel as either nonplant or belonging to one of the three organ types (leaf, stalk, panicle). While many current methods for segmentation focus on separating plant pixels from background, organ-specific segmentation makes it feasible to measure a wider range of plant properties. Manually scored training data for a set of hyperspectral images collected from a sorghum association population was used to train and evaluate a set of supervised classification models. Many algorithms show acceptable accuracy for this classification task. …

Isoseq Transcriptome Assembly Of C3 Panicoid Grasses Provides Tools To Study Evolutionary Change In The Panicoideae, Daniel S. Carvalho, Aime V. Nishimwe, James C. Schnable

Center for Plant Science Innovation: Faculty Publications

The number of plant species with genomic and transcriptomic data has been increasing rapidly. The grasses—Poaceae—have been well represented among species with published reference genomes. However, as a result the genomes of wild grasses are less frequently targeted by sequencing efforts. Sequence data from wild relatives of crop species in the grasses can aid the study of domestication, gene discovery for breeding and crop improvement, and improve our understanding of the evolution of C₄ photosynthesis. Here, we used long-read sequencing technology to characterize the transcriptomes of three C₃ panicoid grass species: Dichanthelium oligosanthes, Chasmanthium laxum, and …

Oxidosqualene Cyclases Involved In The Biosynthesis Of Triterpenoids In Quercus Suber Cork, Lucas Busta, Olga Serra, Ok Tae Kim, Marisa Molinas, Irene Peré-Fossoul, Mercè Figueras, Reinhard Jetter

Center for Plant Science Innovation: Faculty Publications

Cork is a water-impermeable, suberin-based material harboring lignin, (hemi)cellulose, and extractable small molecules (primarily triterpenoids). Extractables strongly influence the properties of suberin-based materials. Though these previous findings suggest a key role for triterpenoids in cork material quality, directly testing this idea is hindered in part because it is not known which genes control cork triterpenoid biosynthesis. Here, we used gas chromatography and mass spectrometry to determine that the majority (>85%) of non-polar extractables from cork were pentacyclic triterpenoids, primarily betulinic acid, friedelin, and hydroxy-friedelin. In other plants, triterpenoids are generated by oxidosqualene cyclases (OSCs). Accordingly, we mined Quercus suber …

Plant Segmentation By Supervised Machine Learning Methods, Jason Adams, Yumou Qiu, Yuhang Xu, James C. Schnable

Center for Plant Science Innovation: Faculty Publications

High-throughput phenotyping systems provide abundant data for statistical analysis through plant imaging. Before usable data can be obtained, image processing must take place. In this study, we used supervised learning methods to segment plants from the background in such images and compared them with commonly used thresholding methods. Because obtaining accurate training data is a major obstacle to using supervised learning methods for segmentation, a novel approach to producing accurate labels was developed. We demonstrated that, with careful selection of training data through such an approach, supervised learning methods, and neural networks in particular, can outperform thresholding methods at segmentation.

Advances In Plant Phenomics: From Data And Algorithms To Biological Insights, Sunil Kumar Kenchanmane Raju, Addie M. Thompson, James Schnable

Center for Plant Science Innovation: Faculty Publications

The measurement of the characteristics of living organisms is referred to as phenotyping (Singh et al., 2016). While the use of phenotyping in plant biology and genetics can be traced back at least to Gregor Mendel sorting and counting peas by shape and pod color 160 years ago, addressing current questions in plant biology, genetics, and breeding often requires increasingly precise phenotyping of a wide range of traits. Accurate phenotyping has played a role in both novel discoveries about the fundamental biology of plants and the development of improved crop varieties around the world. With the advent of inexpensive genotyping …

Leaf Angle Extractor: A High-Throughput Image Processing Framework For Leaf Angle Measurements In Maize And Sorghum, Sunil Kumar Kenchanmane Raju, Miles Adkins, Alex Enersen, Daniel Santana De Carvalho, Anthony J. Studer, Baskar Ganapathysubramanian, Patrick S. Schnable, James C. Schnable

Center for Plant Science Innovation: Faculty Publications

PREMISE: Maize yields have significantly increased over the past half-century owing to advances in breeding and agronomic practices. Plants have been grown in increasingly higher densities due to changes in plant architecture resulting in plants with more upright leaves, which allows more efficient light interception for photosynthesis. Natural variation for leaf angle has been identified in maize and sorghum using multiple mapping populations. However, conventional phenotyping techniques for leaf angle are low throughput and labor intensive, and therefore hinder a mechanistic understanding of how the leaf angle of individual leaves changes over time in response to the environment.

METHODS …

Methods And Compositions For Obtaining Useful Plant Traits, Sally Mackenzie, Michael Fromm, Kamaldeep Viridi, Yashitola Wamboldt

Center for Plant Science Innovation: Faculty Publications

The present invention provides methods for obtaining plants that exhibit useful traits by perturbation of plastid function in plant rootstocks and grafting the rootstocks to scions. Methods for identifying genetic loci that provide for useful traits in plants and plants produced with those loci are also provided. In addition, plants that exhibit the useful traits, parts of the plants including seeds, and products of the plants are provided as well as methods of using the plants. Recombinant DNA vectors and transgenic plants comprising those vectors that provide for plastid perturbation are also provided.

Interspecific Analysis Of Diurnal Gene Regulation In Panicoid Grasses Identifies Known And Novel Regulatory Motifs, Xianjun Lai, Claire Bendix, Lang Yan, Yang Zhang, James C. Schnable, Frank G. Harmon

Center for Plant Science Innovation: Faculty Publications

Background: The circadian clock drives endogenous 24-h rhythms that allow organisms to adapt and prepare for predictable and repeated changes in their environment throughout the day-night (diurnal) cycle. Many components of the circadian clock in Arabidopsis thaliana have been functionally characterized, but comparatively little is known about circadian clocks in grass species including major crops like maize and sorghum.

Results: Comparative research based on protein homology and diurnal gene expression patterns suggests the function of some predicted clock components in grasses is conserved with their Arabidopsis counterparts, while others have diverged in function. Our analysis of diurnal gene expression in …

Voxel Carving-Based 3d Reconstruction Of Sorghum Identifies Genetic Determinants Of Light Interception Efficiency, Mathieu Gaillard, Chenyong Miao, James C. Schnable, Bedrich Benes

Center for Plant Science Innovation: Faculty Publications

Changes in canopy architecture traits have been shown to contribute to yield in- creases. Optimizing both light interception and light interception efficiency of agri- cultural crop canopies will be essential to meeting the growing food needs. Canopy architecture is inherently three-dimensional (3D), but many approaches to measuring canopy architecture component traits treat the canopy as a two-dimensional (2D) structure to make large scale measurement, selective breeding, and gene identifi- cation logistically feasible. We develop a high throughput voxel carving strategy to reconstruct 3D representations of sorghum from a small number of RGB photos. Our approach builds on the voxel carving …

Compounds For Increasing Lipid Synthesis And Storage, Concetta Dirusso, Nishikant Wase

Center for Plant Science Innovation: Faculty Publications

This invention relates to methods for increasing lipid accumulation and lipid production in cells. Methods of producing biofuel from cells and preparing nutraceuticals comprising lipids produced according to a method provided herein are also provided.

Non-Homology-Based Prediction Of Gene Functions In Maize (Zea Mays Ssp. Mays), Xiuru Dai, Zheng Xu, Zhikai Liang, Xiaoyu Tu, Silin Zhong, James C. Schnable, Pinghua Li

Center for Plant Science Innovation: Faculty Publications

Advances in genome sequencing and annotation have eased the difficulty of identifying new gene sequences. Predicting the functions of these newly identified genes remains challenging. Genes descended from a common ancestral sequence are likely to have common functions. As a result, homology is widely used for gene function pre- diction. This means functional annotation errors also propagate from one species to another. Several approaches based on machine learning classification algorithms were evaluated for their ability to accurately predict gene function from non-homology gene features. Among the eight supervised classification algorithms evaluated, random- forest-based prediction consistently provided the most accurate gene …

A High-Throughput Phenotyping Pipeline For Image Processing And Functional Growth Curve Analysis, Ronghao Wang, Yumuo Qiu, Yuzhen Zhou, Zhikai Liang, James Schnable

Center for Plant Science Innovation: Faculty Publications

High-throughput phenotyping system has become more and more popular in plant science research. The data analysis for such a system typically involves two steps: plant feature extraction through image processing and statistical analysis for the extracted features. The current approach is to perform those two steps on different platforms. We develop the package “implant” in R for both robust feature extraction and functional data analysis. For image processing, the “implant” package provides methods including thresholding, hidden Markov random field model, and morphological operations. For statistical analysis, this package can produce nonparametric curve fitting with its confidence region for plant growth. …

Leaf Angle Extractor: A High-Throughput Image Processing Framework For Leaf Angle Measurements In Maize And Sorghum, Sunil Kumar Kenchanmane Raju, Miles Adkins, Alex Enersen, Daniel Santana De Carvalho, Anthony J. Studer, Baskar Ganapathysubramanian, Patrick Schnable, James C. Schnable

Center for Plant Science Innovation: Faculty Publications

PREMISE: Maize yields have significantly increased over the past half-century owing to advances in breeding and agronomic practices. Plants have been grown in increasingly higher densities due to changes in plant architecture resulting in plants with more upright leaves, which allows more efficient light interception for photosynthesis. Natural variation for leaf angle has been identified in maize and sorghum using multiple mapping populations. However, conventional phenotyping techniques for leaf angle are low throughput and labor intensive, and therefore hinder a mechanistic understanding of how the leaf angle of individual leaves changes over time in response to the environment.

METHODS: High-throughput …

Advances In Plant Phenomics: From Data And Algorithms To Biological Insights, Sunil K. Kenchanmane Raju, Addie M. Thompson, James Schnable

Center for Plant Science Innovation: Faculty Publications

The measurement of the characteristics of living organisms is re- ferred to as phenotyping (Singh et al., 2016). While the use of phe- notyping in plant biology and genetics can be traced back at least to Gregor Mendel sorting and counting peas by shape and pod color 160 years ago, addressing current questions in plant biology, genet- ics, and breeding often requires increasingly precise phenotyping of a wide range of traits. Accurate phenotyping has played a role in both novel discoveries about the fundamental biology of plants and the development of improved crop varieties around the world. With the advent …

Metabolic Profiles Of Six African Cultivars Of Cassava (Manihot Esculenta Crantz) Highlight Bottlenecks Of Root Yield, Toshihiro Obata, Patrick A.W. Klemens, Laise Rosado-Souza, Armin Schlereth, Andreas Gisel, Livia Stavolone, Wolfgang Zierer, Nicolas Morales, Lukas A. Mueller, Samuel C. Zeeman, Frank Ludewig, Mark State, Uwe Sonnewald, H. Ekkehard Neuhaus, Alisdair R. Femie

Center for Plant Science Innovation: Faculty Publications

Cassava is an important staple crop in sub-Saharan Africa, due to its high productivity even on nutrient poor soils. The metabolic characteristics underlying this high productivity are poorly understood including the mode of photosynthesis, reasons for the high rate of photosynthesis, the extent of source/sink limitation, the impact of environment, and the extent of variation between cultivars. Six commercial African cassava cultivars were grown in a greenhouse in Erlangen, Germany, and in the field in Ibadan, Nigeria. Source leaves, sink leaves, stems and storage roots were harvested during storage root bulking and analyzed for sugars, organic acids, amino acids, phosphorylated …

Increased Power And Accuracy Of Causal Locus Identification In Time Series Genome-Wide Association In Sorghum1[Open], Chenyong Miao, Yuhang Xu, Sanzhen Liu, Patrick S. Schnable, James C. Schnable

Center for Plant Science Innovation: Faculty Publications

The phenotypes of plants develop over time and change in response to the environment. New engineering and computer vision technologies track these phenotypic changes. Identifying the genetic loci regulating differences in the pattern of phenotypic change remains challenging. This study used functional principal component analysis (FPCA) to achieve this aim. Time series phenotype data were collected from a sorghum (Sorghum bicolor) diversity panel using a number of technologies including conventional color photography and hyperspectral imaging. This imaging lasted for 37 d and centered on reproductive transition. A new higher density marker set was generated for the same population. Several genes …

Improving On Modis Mcd64a1 Burned Area Estimates In Grassland Systems: A Case Study In Kansas Flint Hills Tall Grass Prairie, Rheinhardt Scholtz, Jayson Prentice, Yao Tang, Dirac Twidwell

Department of Agronomy and Horticulture: Faculty Publications

Uncertainty in satellite-derived burned area estimates are especially high in grassland systems, which are some of the most frequently burned ecosystems in the world. In this study, we compare differences in predicted burned area estimates for a region with the highest fire activity in North America, the Flint Hills of Kansas, USA, using the moderate resolution imaging spectroradiometer (MODIS) MCD64A1 burned area product and a customization of the MODIS MCD64A1 product using a major ground-truthing effort by the Kansas Department of Health and Environment (KDHE-MODIS customization). Local-scale ground-truthing and the KDHE-MODIS product suggests MODIS burned area estimates under predicted fire …

A Global Database Of Soil Nematode Abundance And Functional Group Composition, Johan Van Den Hoogen, Stefan Geisen, Thomas W. Crowther, Peter Mullin, Many Co-Authors

Department of Plant Pathology: Faculty Publications

As the most abundant animals on earth, nematodes are a dominant component of the soil community. They play critical roles in regulating biogeochemical cycles and vegetation dynamics within and across landscapes and are an indicator of soil biological activity. Here, we present a comprehensive global dataset of soil nematode abundance and functional group composition. This dataset includes 6,825 georeferenced soil samples from all continents and biomes. For geospatial mapping purposes these samples are aggregated into 1,933 unique 1-km pixels, each of which is linked to 73 global environmental covariate data layers. Altogether, this dataset can help to gain insight into …

Non-Homology-Based Prediction Of Gene Functions In Maize (Zea Mays Ssp. Mays), Xiuru Dai, Zheng Xu, Zhikai Liang, Xiaoyu Tu, Silin Zhong, James Schnable, Pinghua Li

Center for Plant Science Innovation: Faculty Publications

Advances in genome sequencing and annotation have eased the difficulty of identifying new gene sequences. Predicting the functions of these newly identified genes remains challenging. Genes descended from a common ancestral sequence are likely to have common functions.As a result, homology is widely used for gene function prediction. This means functional annotation errors also propagate from one species to another. Several approaches based on machine learning classification algorithms were evaluated for their ability to accurately predict gene function from non-homology gene features. Among the eight supervised classification algorithms evaluated, random forest-based prediction consistently provided the most accurate gene function prediction. …

Evaluating The Impact Of Grafting On Local Tomato Production In Nebraska, Raihanah Hassim, Samuel E. Wortman, Ashley A. Thompson, Stacy A. Adams

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Grafting has been successfully used in vegetable production for tomatoes, peppers, eggplants, cucumbers, and watermelon. Besides its usefulness for managing soil-borne diseases, grafting can improve nutrient uptake and yield. However, few studies have assessed the effects of grafting and soil fertility management on yield of open field-grown tomatoes in the Midwest. Therefore, the objective of this two-year research was to better document the effects of grafting heirloom and hybrid tomato cultivar onto hybrid tomato rootstocks on tomato yield and quality. The field experiments were located at the University of Nebraska Lincoln - East Campus in Lincoln, West Central Research and …

Growth And Development, From: Forages: The Science Of Grassland Agriculture, Volume Ii, Robert B. Mitchell, Daren Redfearn, Kenneth J. Moore

Department of Agronomy and Horticulture: Faculty Publications

The growth and development of forage plants is an amazing process. In some annual grasses such as cereal rye, plants can go from the late vegetative stage to fully-flowered in less than two weeks. Conversely, some perennial grasses like indiangrass can go from the vegetative stage to the elongation stage, then enter a quiescent phase for several weeks until adequate moisture is available which then moves plants into the flowering stages to complete the seed production process. Understanding the developmental morphology of forage plants is important for making good management decisions. Many such decisions involve timing the initiation or termination …

Principles, Applications, And Biosafety Of Plant Genome Editing Using Crispr-Cas9, Kaoutar El-Mounadi, María Luisa Morales-Floriano, Hernan Garcia-Ruiz

Department of Plant Pathology: Faculty Publications

The terms genome engineering, genome editing, and gene editing, refer to modifications (insertions, deletions, substitutions) in the genome of a living organism. The most widely used approach to genome editing nowadays is based on Clustered Regularly Interspaced Short Palindromic Repeats and associated protein 9 (CRISPR-Cas9). In prokaryotes, CRISPR-Cas9 is an adaptive immune system that naturally protects cells from DNA virus infections. CRISPR-Cas9 has been modified to create a versatile genome editing technology that has a wide diversity of applications in medicine, agriculture, and basic studies of gene functions. CRISPR-Cas9 has been used in a growing number of monocot and dicot …

Variation Profile Of The Orthotospovirus Genome, Deepti Nigam, Hernan Garcia Ruiz

Department of Plant Pathology: Faculty Publications

Orthotospoviruses are plant-infecting members of the family Tospoviridae (order Bunyavirales), have a broad host range and are vectored by polyphagous thrips in a circulative- propagative manner. Because diverse hosts and vectors impose heterogeneous selection constraints on viral genomes, the evolutionary arms races between hosts and their pathogens might be manifested as selection for rapid changes in key genes. These observations suggest that orthotospoviruses contain key genetic components that rapidly mutate to mediate host adaptation and vector transmission. Using complete genome sequences, we profiled genomic variation in orthotospoviruses. Results show that the three genomic segments contain hypervariable areas at homologous locations …

Allelic Variation In Rice Fertilization Independent Endosperm 1 Contributes To Grain Width Under High Night Temperature Stress, Balpreet K. Dhatt, Puneet Paul, Jaspreet Sandhu, Waseem Hussain, Larissa Irvin, Feiyu Zhu, Maria Arlene Adviento-Borbe, Argelia Lorence, Paul Staswick, Hongfeng Yu, Gota Morota, Harkamal Walia

Department of Agronomy and Horticulture: Faculty Publications

A higher minimum (night-time) temperature is considered a greater limiting factor for reduced rice yield than a similar increase in maximum (daytime) temperature. While the physiological impact of high night temperature (HNT) has been studied, the genetic and molecular basis of HNT stress response remains unexplored.

We examined the phenotypic variation for mature grain size (length and width) in a diverse set of rice accessions under HNT stress. Genome-wide association analysis identified several HNT-specific loci regulating grain size as well as loci that are common for optimal and HNT stress conditions.

A novel locus contributing to grain width under HNT …

Voxel Carving-Based 3d Reconstruction Of Sorghum Identifies Genetic Determinants Of Light Interception Efficiency, Mathieu Gaillard, Chenyong Miao, James Schnable, Bedrich Benes

Department of Agronomy and Horticulture: Faculty Publications

Changes in canopy architecture traits have been shown to contribute to yield increases. Optimizing both light interception and light interception efficiency of agricultural crop canopies will be essential to meeting the growing food needs. Canopy architecture is inherently three-dimensional (3D), but many approaches to measuring canopy architecture component traits treat the canopy as a two-dimensional (2D) structure to make large scale measurement, selective breeding, and gene identification logistically feasible. We develop a high throughput voxel carving strategy to reconstruct 3D representations of sorghum from a small number of RGB photos. Our approach builds on the voxel carving algorithm to allow …

Genome-Wide Identification And Analysis Of Heterotic Loci In Three Maize Hybrids, Hongjun Liu, Qin Wang, Mengjiao Chen, Yahui Ding, Xuerong Yang, Jie Liu, Xiaohan Li, Congcong Zhou, Qilin Tian, Yiqi Lu, Danlin Fan, Junpeng Shi, Lin Zhang, Congbin Kang, Mingfei Mingfei Sun, Fangyuan Li, Yujian Wu, Yongzhong Zhang, Baoshen Liu, Xiang Yu Zhao, Qi Feng, Jinliang Yang, Bin Han, Jinsheng Lai, Xian Sheng Zhang, Xuehui Huang

Department of Agronomy and Horticulture: Faculty Publications

Heterosis, or hybrid vigour, is a predominant phenomenon in plant genetics, serving as the basis of crop hybrid breeding, but the causative loci and genes underlying heterosis remain unclear in many crops. Here, we present a large-scale genetic analysis using 5360 offsprings from three elite maize hybrids, which identifies 628 loci underlying 19 yield-related traits with relatively high mapping resolutions. Heterotic pattern investigations of the 628 loci show that numerous loci, mostly with complete–incomplete dominance (the major one) or overdominance effects (the secondary one) for heterozygous genotypes and nearly equal proportion of advantageous alleles from both parental lines, are the …

Mutations In Virus-Derived Small Rnas, Deepti Nigam, Katherine Latourrette, Hernan Garcia Ruiz

Department of Plant Pathology: Faculty Publications

RNA viruses exist as populations of genome variants. Virus-infected plants accumulate 21–24 nucleotide small interfering RnAs (siRnAs) derived from viral RnA (virus-derived siRnAs) through gene silencing. This paper describes the profile of mutations in virus-derived siRNAs for three members of the family Potyviridae: Turnip mosaic virus (tuMV), Papaya ringspot virus (pRSV) and Wheat streak mosaic virus (WSMV). for tuMV in Arabidopsis thaliana, profiles were obtained for mechanically inoculated rosette leaves and systemically infected cauline leaves and inflorescence. Results are consistent withselection pressure on the viral genome imposed by local and systemic movement. By genetically removing gene silencing in the plant …