Plant Breeding and Genetics Commons^™

Grain Yield And Yield-Related Qtl Validation Using Reciprocal Recombinant Inbred Chromosome Lines In Wheat, Neway C. Mengistu

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

Grain yield and yield-related traits are the most important economic factors for bread wheat (Triticum aestivum L.) improvement. Grain yield (GYLD) and yield-related quantitative trait loci (QTLs) were previously identified by using a population of recombinant inbred chromosome lines (RICLs) developed from cultivar ‘Cheyenne’ (CNN) and its substitution line CNN(WI3A), where the 3A chromosome of cultivar ‘Wichita’ (WI) was substituted for the CNN chromosome 3A. The objectives of this study were to identify and validate GYLD and yield-related QTLs previously identified in CNN(RICLs-3A) studies by using the mirror population WI(RICLs-3A), where chromosome 3A of CNN and WI were now …

The Green Revolution Of The 1960'S And Its Impact On Small Farmers In India, Kathryn Sebby

Department of Environmental Studies: Undergraduate Student Theses

The Green Revolution was initiated in the 1960’s to address the issue of malnutrition in the developing world. The technology of the Green Revolution involved bio-engineered seeds that worked in conjunction with chemical fertilizers and heavy irrigation to increase crop yields. The technology was readily adopted in many stated in India and for some was a great success. However, there were many farmers who could not afford the inputs necessary to participate in the Green Revolution and gaps between social classes widened as wealthy farmers got wealthier and poor farmers lagged behind. This paper discusses how small farmers were affected …

The Pseudomonas Syringae Type Iii Effector Hopg1 Targets Mitochondria, Alters Plant Development, And Suppresses Plant Innate Immunity, Anna Block, Ming Guo, Guangyong Li, Christian Elowsky, Thomas Clemente, James R. Alfano

Center for Plant Science Innovation: Faculty Publications

The bacterial plant pathogen Pseudomonas syringae uses a type III protein secretion system to inject type III effectors into plant cells. Primary targets of these effectors appear to be effector-triggered immunity (ETI) and pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI). The type III effector HopG1 is a suppressor of ETI that is broadly conserved in bacterial plant pathogens. Here we show that HopG1 from P. syringae pv. tomato DC3000 also suppresses PTI. Interestingly, HopG1 localizes to plant mitochondria, suggesting that its suppression of innate immunity may be linked to a perturbation of mitochondrial function. While HopG1 possesses no obvious mitochondrial signal …

Alkylresorcinol Synthases Expressed In Sorghum Bicolor Root Hairs Play An Essential Role In The Biosynthesis Of The Allelopathic Benzoquinone Sorgoleone, Daniel Cook, Agnes M. Rimando, Thomas E. Clemente, Joachim Schroder, Franck E. Dayan, N. P. Dhammika Nanayakkara, Zhiqiang Pan, Brice P. Noonan, Mark Fishbein, Ikuro Abe, Stephen O. Duke, Scott R. Baerson

Center for Plant Science Innovation: Faculty Publications

Sorghum bicolor is considered to be an allelopathic crop species, producing phytotoxins such as the lipid benzoquinone sorgoleone, which likely accounts for many of the allelopathic properties of Sorghum spp. Current evidence suggests that sorgoleone biosynthesis occurs exclusively in root hair cells and involves the production of an alkylresorcinolic intermediate (5-[(Z,Z)-8',11',14'-pentadecatrienyl]resorcinol) derived from an unusual 16:3D^9,12,15 fatty acyl-CoA starter unit. This led to the suggestion of the involvement of one or more alkylresorcinol synthases (ARSs), type III polyketide synthases (PKSs) that produce 5-alkylresorcinols using medium to long-chain fatty acyl-CoA starter units via iterative condensations with malonyl-CoA. In an effort …

Turnover Of Mature Mirnas And Sirnas In Plants And Algae, Heriberto Cerutti, Fadia Ibrahim

Center for Plant Science Innovation: Faculty Publications

rnicroRNAs (miRNAs) and small interfering RNAs (siRNAs) play important roles in gene regulation and defense responses against transposons and viruses in eukaryotes. These small RNAs generally trigger the silencing of cognate sequences through a variety of mechanisms, including RNA degradation, translational inhibition, and transcriptional repression. In the past few years, the synthesis and the mode of action of miRNAs and siRNAs have attracted great attention. However, relatively little is known about mechanisms of quality control during small RNA biogenesis as well as those that regulate mature small RNA stability. Recent studies in Arabidopsis thaliana and Caenorhahditis elegans have implicated 3′-to-5′ …

Translational Inhibition By Micrornas In Plants, Bin Yu, Hai Wang

Center for Plant Science Innovation: Faculty Publications

MicroRNAs (miRNAs) are 21–24 nucleotide riboregulators, which selectively repress gene expression through transcript cleavage and/or translational inhibition. It was thought that most plant miRNAs act through target transcript cleavage due to the high degree of complementarity between miRNAs and their targets. However, recent studies have suggested widespread translational inhibition by miRNAs in plants. The mechanisms underlining translational inhibition by plant miRNAs are largely unknown, but existing evidence has indicated that plants and animals share some mechanistic similarity of translational inhibition. Translational inhibition by miRNAs has been shown to regulate floral patterning, floral timing, and stress responses. This chapter covers recent …

Genetic Diversity Of Wheat Cultivars From Turkey And U. S. Great Plains, Anyamanee Auvuchanon

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

Genetic diversity of wheat cultivars from Turkey and the Great Plains was studied under the hypothesis ‘Turkey’ wheat originated from Turkey and is the original hard red winter wheat landrace in the Great Plains. Wheat cultivars in Turkey and the Great Plains were selected for adaptation in two countries which were similar in climate. Twenty-two Turkish and twenty-three Great Plains wheat cultivars were selected for this study using SSR markers, agronomic, and end-use quality traits data. Wheat cultivars were clustered into five groups based on SSR markers and the clustering largely followed their countries of origin and pedigree. Modern Great …

Spring Seed Guide 2010: Nebraska Variety And Hybrid Tests -- Soybeans, Teshome Regassa, Robert N. Klein, Bruce Anderson, Charles A. Shapiro, Jim Krall

Department of Agronomy and Horticulture: Faculty Publications

NEBRASKA SOYBEAN VARIETY TESTS 2009

Crop Production Summary: The November 2009 estimated soybean yield for Nebraska was 52 bushels per acre from 4.800 million harvested acres. The total production of soybeans for the state was forecasted at 247 million bushels. These estimates are from the November National Agricultural Statistics Service.

Wheat (Triticum Aestivum) Nam Proteins Regulate The Translocation Of Iron, Zinc, And Nitrogen Compounds From Vegetative Tissues To Grain, Brian M. Waters, Cristobal Uauy, Jorge Dubcovsky, Michael A. Grusak

Department of Agronomy and Horticulture: Faculty Publications

The NAM-B1 gene is a NAC transcription factor that affects grain nutrient concentrations in wheat (Triticum aestivum). An RNAi line with reduced expression of NAM genes has lower grain protein, iron (Fe), and zinc (Zn) concentrations. To determine whether decreased remobilization, lower plant uptake, or decreased partitioning to grain are responsible for this phenotype, mineral dynamics were quantified in wheat tissues throughout grain development. Control and RNAi wheat were grown in potting mix and hydroponics. Mineral (Ca, Cu, Fe, K, Mg, Mn, P, S, and Zn) and nitrogen (N) contents of organs were determined at regular intervals to …

Evaluating Hazelnut Cultivars For Yield, Quality And Disease Resistance, Sam Tobin

Department of Environmental Studies: Undergraduate Student Theses

ABSTRACT This long term study focuses on testing various hazelnut cultivars for yield, nut quality and disease resistance. There are various cultivars that are being tested for these desired traits but only the Grand Traverse and Skinner will be applicable for the results of this localized study. The desired traits of commercial nut production are best matched by these two cultivars. Results from previous harvests will be used to draw trends to recommend commercially functional cultivars in Eastern Nebraska.

Genetic Control Of Sorghum Grain Color, René Clará Valencia, William L. Rooney

INTSORMIL Presentations

Today there is a real interest in the utilization of sorghum grain as a substitute for wheat in baked goods and as a substitute for yellow maize in animal feed. Sorghum grain color and quality are important characteristics in the baking and livestock feed industries. For that reason it is necessary to develop varieties that are suitable for the food and feed industries.

The purpose of this bulletin is to briefly describe the main genetic characteristics that objectively affect sorghum grain appearance and quality.

The pericarp and glume color affect the color of the finished products made with sorghum grain. …

Control Genético Del Color Del Grano De Sorgo, René Clará Valencia, William L. Rooney

INTSORMIL Presentations

Actualmente existe un gran interés en la utilización del grano de sorgo como fuente de energía en la elaboración de alimentos para el consumo humano y/o animal, sustituyendo al trigo en la panificación y al maíz amarillo en la elaboración de alimentos concentrados; para tal efecto es necesario conocer el control genético del color del grano para mejorar su calidad.

El objetivo de esta información es describir brevemente las características genéticas principales, actualmente conocidas y que afectan objetivamente la apariencia del grano de sorgo.

El color del pericarpio y la gluma de la flor afectan la coloración de los productos …

Roadmap For Future Research On Plant Pathogen Effectors, James R. Alfano

Center for Plant Science Innovation: Faculty Publications

Bacterial and eukaryotic plant pathogens deliver effector proteins into plant cells to promote pathogenesis. Bacterial pathogens containing type III protein secretion systems are known to inject many of these effectors into plant cells. More recently, oomycete pathogens have been shown to possess a large family of effectors containing the RXLR motif, and many effectors are also being discovered in fungal pathogens. Although effector activities are largely unknown, at least a subset suppress plant immunity. A plethora of new plant pathogen genomes that will soon be available thanks to next-generation sequencing technologies will allow the identification of many more effectors. This …

Histone H3 Phosphorylation: Universal Code Or Lineage Specific Dialects?, Heriberto Cerutti, J. Armando Casas-Mollano

Center for Plant Science Innovation: Faculty Publications

Post-translational modifications of histones modulate the functional landscape of chromatin and impinge on many DNA-mediated processes. Phosphorylation of histone H3 plays a role in the regulation of gene expression and in chromosome condensation/segregation. Certain evolutionarily conserved residues on histone H3—namely Thr3, Ser10, Thr11, and Ser28—are phosphorylated during interphase or mitosis in both metazoa and plants. However, many of the kinases involved in these events appear to have evolved independently in different lineages. Likewise, the mechanistic function of specific phosphorylated amino acids, although poorly understood, also seems to differ among eukaryotes. Moreover, some modifications, such as phosphorylation of histone H3 Ser10, …

Protein-Protein Interactions Of Tandem Affinity Purified Protein Kinases From Rice, Jai S. Rohila, Mei Chen, Shuo Chen, Johann Chen, Ronald L. Cerny, Christopher Dardick, Patrick Canlas, Hiroaki Fujii, Michael Gribskov, Siddhartha Kanrar, Lucas Knoflicek, Becky Stevenson, Mingtang Xie, Xia Xu, Xianwu Zheng, Jing-Kang Zhu, Pamela Ronald, Michael E. Fromm

Center for Plant Science Innovation: Faculty Publications

Eighty-eight rice (Oryza sativa) cDNAs encoding rice leaf expressed protein kinases (PKs) were fused to a Tandem Affinity Purification tag (TAP-tag) and expressed in transgenic rice plants. The TAP-tagged PKs and interacting proteins were purified from the T1 progeny of the transgenic rice plants and identified by tandem mass spectrometry. Forty-five TAPtagged PKs were recovered in this study and thirteen of these were found to interact with other rice proteins with a high probability score. In vivo phosphorylated sites were found for three of the PKs. A comparison of the TAP-tagged data from a combined analysis of 129 …

Participation Of Leaky Ribosome Scanning In Protein Dual Targeting By Alternative Translation Initiation In Higher Plants, Yashitola Wamboldt, Saleem Mohammed, Christian Elowsky, Chris Wittgren, Wilson B. M. De Paula, Sally Ann Mackenzie

Center for Plant Science Innovation: Faculty Publications

Postendosymbiotic evolution has given rise to proteins that are multiply targeted within the cell. Various mechanisms have been identified to permit the expression of proteins encoding distinct N termini from a single gene. One mechanism involves alternative translation initiation (aTI). We previously showed evidence of aTI activity within the Arabidopsis thaliana organellar DNA polymerase gene POLg2. Translation initiates at four distinct sites within this gene, two non-AUG, to produce distinct plastid and mitochondrially targeted forms of the protein. To understand the regulation of aTI in higher plants, we used Polg2 as a model to investigate both cis- and trans …

Intergenic Transcription By Rna Polymerase Ii Coordinates Pol Iv And Pol V In Sirna-Directed Transcriptional Gene Silencing In Arabidopsis, Binglian Zheng, Zhengming Wang, Shengben Li, Bin Yu, Jin -Yuan Liu, Xuemei Chen

Center for Plant Science Innovation: Faculty Publications

Intergenic transcription by RNA Polymerase II (Pol II) is widespread in plant and animal genomes, but the functions of intergenic transcription or the resulting noncoding transcripts are poorly understood. Here, we show that Arabidopsis Pol II is indispensable for endogenous siRNA-mediated transcriptional gene silencing (TGS) at intergenic low-copy-number loci, despite the presence of two other polymerases—Pol IV and Pol V—that specialize in TGS through siRNAs. We show that Pol II produces noncoding scaffold transcripts that originate outside of heterochromatic, siRNA-generating loci. Through these transcripts and physical interactions with the siRNA effector protein ARGONAUTE4 (AGO4), Pol II recruits AGO4/siRNAs to homologous …

Alternative Cereal Processing Technologies [Conference Program And Proceedings] (Lobatse, Botswana, November 4-6, 2008), Martin Kebakile, Kemelo Ookeditse

INTSORMIL Presentations

Objectives of the workshop:

To review the current status of local cereals production and processing explore opportunities for growing the cereal industry.

To promote diversification of cereal processing by sensitizing all players and stakeholders in the cereals industry about readily available alternative cereals processing technologies which have commercial potential.

To promote and strengthen collaboration between local and international researchers, as well as fostering strategic partnerships between researchers and users of technologies to develop customer tailored processing technologies.

Phytopathogen Type Iii Effector Weaponry And Their Plant Targets, Anna Block, Guangyong Li, Zheng Qing Fu, James R. Alfano

Center for Plant Science Innovation: Faculty Publications

Phytopathogenic bacteria suppress plant innate immunity and promote pathogenesis by injecting proteins called type III effectors into plant cells using a type III protein secretion system. These type III effectors use at least three major strategies to alter host responses. One strategy is to alter host protein turnover, either by direct cleavage or by modulating ubiquitination and targeting to the 26S proteasome. Another strategy involves alteration of RNA metabolism by transcriptional activation or ADP-ribosylation of RNA-binding proteins. A third major strategy is to inhibit the kinases involved in plant defence signalling, either by removing phosphates or by direct inhibition. The …

The Small Glycine-Rich Rna Binding Protein Atgrp7 Promotes Floral Transition In Arabidopsis Thaliana, Corinna Streitner, Selahattin Danisman, Franziska Wehrle, Jan C. Schoning, James R. Alfano, Dorothee Staiger

Center for Plant Science Innovation: Faculty Publications

The RNA binding protein AtGRP7 is part of a circadian slave oscillator in Arabidopsis thaliana that negatively autoregulates its own mRNA, and affects the levels of other transcripts. Here, we identify a novel role for AtGRP7 as a flowering-time gene. An atgrp7-1 T-DNA mutant flowers later than wild-type plants under both long and short days, and independent RNA interference lines with reduced levels of AtGRP7, and the closely related AtGRP8 protein, are also late flowering, particularly in short photoperiods. Consistent with the retention of a photoperiodic response, the transcript encoding the key photoperiodic regulator CONSTANS oscillates with a similar pattern …

Quantitative Trait Locus Mapping For Seed Mineral Concentrations In Two Arabidopsis Thaliana Recombinant Inbred Populations, Brian M. Waters, Michael A. Grusak

Department of Agronomy and Horticulture: Faculty Publications

Biofortification of foods, achieved by increasing the concentrations of minerals such as iron (Fe) and zinc (Zn), is a goal of plant scientists. Understanding genes that influence seed mineral concentration in a model plant such as Arabidopsis could help in the development of nutritionally enhanced crop cultivars. Quantitative trait locus (QTL) mapping for seed concentrations of calcium (Ca), copper (Cu), Fe, potassium (K), magnesium (Mg), manganese (Mn), phosphorus (P), sulfur (S), and Zn was performed using two recombinant inbred line (RIL) populations, Columbia (Col) × Landsberg erecta (Ler) and Cape Verde Islands (Cvi) × Ler, grown …

A Pseudomonas Syringae Pv. Tomato Dc3000 Mutant Lacking The Type Iii Effector Hopq1-1 Is Able To Cause Disease In The Model Plant Nicotiana Benthamiana, Chia-Fong Wei, Brian H. Kvitko, Rena Shimizu, Emerson Crabill, James R. Alfano, Nai-Chun Lin, Gregory B. Martin, Hsiou-Chen Huang, Alan Collmer

Center for Plant Science Innovation: Faculty Publications

The model pathogen Pseudomonas syringae pv. tomato DC3000 causes bacterial speck in tomato and Arabidopsis, but Nicotiana benthamiana, an important model plant, is considered to be a non-host. Strain DC3000 injects approximately 28 effector proteins into plant cells via the type III secretion system (T3SS). These proteins were individually delivered into N. benthamiana leaf cells via T3SS-proficient Pseudomonas fluorescens, and eight, including HopQ1-1, showed some capacity to cause cell death in this test. Four gene clusters encoding 13 effectors were deleted from DC3000: cluster II (hopH1, hopC1), IV (hopD1, hopQ1-1, hopR1), IX (hopAA1-2, hopV1, hopAO1, hopG1), and native plasmid pDC3000A …

Pseudomonas SyringaeHrpj Is A Type Iii Secreted Protein That Is Required For Plant Pathogenesis, Injection Of Effectors,And Secretion Of The Hrpz1 Harpin, Zheng Qing Fu, Ming Guo, James R. Alfano

Center for Plant Science Innovation: Faculty Publications

The bacterial plant pathogen Pseudomonas syringae requires a type III protein secretion system (TTSS) to cause disease. The P. syringae TTSS is encoded by the hrp-hrc gene cluster. One of the genes within this cluster, hrpJ, encodes a protein with weak similarity to YopN, a type III secreted protein from the animal pathogenic Yersinia species. Here, we show that HrpJ is secreted in culture and translocated into plant cells by the P. syringae pv. tomato DC3000 TTSS. A DC3000 hrpJ mutant, UNL140, was greatly reduced in its ability to cause disease symptoms and multiply in Arabidopsis thaliana …

Identifying Superior Hybrid Hazelnut Plants In Southeast Nebraska, Elizabeth A. Hammond

School of Natural Resources: Dissertations, Theses, and Student Research

The goal of this observational study is to identify productive hybrid hazelnut plants suitable for commercial production. The objectives of this studywere to 1) examine a plantation of hybrid hazelnut plants grown in Southeast Nebraska for the presence of eastern filbert blight (EFB); 2) identify high yielding hybrid hazelnut plants; and 3) characterize plant and nut features of selected high yielding plants.

Data were collected from a 3.64 hectare (9 acre) planting of 5,200 hybrid hazelnut plant located at Arbor Day Farm in Nebraska City, Otoe County, Nebraska. Plants were grown on 1.5 m x 4.6 m (5 foot x …

A Highly Efficient Transient Protoplast System For Analyzing Defence Gene Expression And Protein–Protein Interactions In Rice, Songbiao Chen, Lizen Tao, Lirong Zeng, Miguel E. Vega-Zanchez, Kenji Umemura, Guo-Liang Wang

Center for Plant Science Innovation: Faculty Publications

The transient assay system based on mesophyll or cultured cell-derived protoplasts has been exploited in several plant species and has become a powerful tool for rapid gene functional analysis and biochemical manipulations. However, the system has not been widely used in rice owing to the difficulties in large-scale isolation of viable rice protoplasts from leaves or suspension-cultured cells. Here, we describe a significantly improved method to isolate a large number of protoplasts from stem and sheath tissues of both young and mature plants. High-level coexpression of multiple constructs and efficient suppression of exogenous and endogenous genes were observed in the …

Pseudomonas Syringae Type Iii Chaperones Shco1, Shcs1, And Shcs2 Facilitate Translocation Of Their Cognate Effectors And Can Substitute For Each Other In The Secretion Of Hopo1-1, Ming Guo, Scott T. Chancey, Fang Tian, Zhengxiang Ge, Yashitola Jamir, James R. Alfano

Center for Plant Science Innovation: Faculty Publications

The Pseudomonas syringae type III secretion system (TTSS) translocates effector proteins into plant cells. Several P. syringae effectors require accessory proteins called type III chaperones (TTCs) to be secreted via the TTSS. We characterized the hopO1-1, hopS1, and hopS2 operons in P. syringae pv. tomato DC3000; these operons encode three homologous TTCs, ShcO1, ShcS1, and ShcS2. ShcO1, ShcS1, and ShcS2 facilitated the type III secretion and/or translocation of their cognate effectors HopO1-1, HopS1, and HopS2, respectively. ShcO1 and HopO1-1 interacted with each other in yeast two-hybrid and coimmunoprecipitation assays. Interestingly, ShcS1 and ShcS2 were capable of substituting for …

The Hrpk Operon Of Pseudomonas Syringae Pv. Tomato Dc3000 Encodes Two Proteins Secreted By The Type Iii (Hrp) Protein Secretion System: Hopb1 And Hrpk, A Putative Type Iii Translocator, Tanja Petnicki-Ocwieja, Karin V. Van Dijk, James R. Alfano

Center for Plant Science Innovation: Faculty Publications

Pseudomonas syringae is a gram-negative bacterial plant pathogen that is dependent on a type III protein secretion system (TTSS) and the effector proteins it translocates into plant cells for pathogenicity. The P. syringae TTSS is encoded by hrp-hrc genes that reside in a central region of a pathogenicity island (Pai). Flanking one side of this Pai is the exchangeable effector locus (EEL). We characterized the transcriptional expression of the open reading frames (ORFs) within the EEL of P. syringae pv. tomato DC3000. One of these ORFs, PSPTO1406 (hopB1) is expressed in the same transcriptional unit as hrpK. …

Reproductive Ecology Of Two Common Woody Species, Juniperus Sabina And Artemisia Santolinifolia, In Mountain Steppes Of Southern Mongolia, Katrin Ronnenberg

Erforschung biologischer Ressourcen der Mongolei / Exploration into the Biological Resources of Mongolia, ISSN 0440-1298

The present study describes the reproductive ecology of the prostrate shrub Juniperus sabina and the dwarf shrub Artemisia santolinifolia in dry mountain steppes of southern Mongolia. Whereas stands of the juniper are located at the drought limit of the genus’ distributional range, the genus Artemisia is typical of central Asian drylands. Both species produce large numbers of reproductive organs. For Juniperus sabina, however, only 2.5% of the morphologically intact seeds were found to be viable. Correspondingly, neither seedlings nor saplings were found in the field, and recruitment by reseeding happens at most rarely under the present climatic conditions.

Instead, …

Disabling Surveillance: Bacterial Type Iii Secretion System Effectors That Suppress Innate Immunity, Avelina Espinosa, James R. Alfano

Center for Plant Science Innovation: Faculty Publications

Many Gram-negative bacterial pathogens of plants and animals are dependent on a type III protein secretion system (TTSS). TTSSs translocate effector proteins into host cells and are capable of modifying signal transduction pathways. The innate immune system of eukaryotes detects the presence of pathogens using specific pathogen recognition receptors (PRRs). Plant PRRs include the FLS2 receptor kinase and resistance proteins. Animal PRRs include Tolllike receptors and nucleotide-binding oligomerization domain proteins. PRRs initiate signal transduction pathways that include mitogen-activated protein kinase (MAPK) cascades that activate defencerelated transcription factors. This results in induction of proinflammatory cytokines in animals, and hallmarks of defence …

The Pseudomonas Syringae Hopptov Protein Is Secreted In Culture And Translocated Into Plant Cells Via The Type Iii Protein Secretion System In A Manner Dependent On The Shcv Type Iii Chaperone, Misty D. Wehling, Ming Guo, Zheng Qing Fu, James R. Alfano

Center for Plant Science Innovation: Faculty Publications

The bacterial plant pathogen Pseudomonas syringae depends on a type III protein secretion system and the effector proteins that it translocates into plant cells to cause disease and to elicit the defense-associated hypersensitive response on resistant plants. The availability of the P. syringae pv. tomato DC3000 genome sequence has resulted in the identification of many novel effectors. We identified the hopPtoV effector gene on the basis of its location next to a candidate type III chaperone (TTC) gene, shcV, and within a pathogenicity island in the DC3000 chromosome. A DC3000 mutant lacking ShcV was unable to secrete detectable amounts …