Plant Breeding and Genetics Commons^™

Msh1-Induced Non-Genetic Variation Provides A Source Of Phenotypic Diversity In Sorghum Bicolor, Roberto De La Rosa Santamaria, Mon-Ray Shao, Guomei Wang, David O. Nino-Liu, Hardik Kundariya, Yashitola Wamboldt, Ismail M. Dweikat, Sally Ann Mackenzie

Department of Agronomy and Horticulture: Faculty Publications

MutS Homolog 1 (MSH1) encodes a plant-specific protein that functions in mitochondria and chloroplasts. We showed previously that disruption or suppression of the MSH1 gene results in a process of developmental reprogramming that is heritable and non-genetic in subsequent generations. In Arabidopsis, this developmental reprogramming process is accompanied by striking changes in gene expression of organellar and stress response genes. This developmentally reprogrammed state, when used in crossing, results in a range of variation for plant growth potential. Here we investigate the implications of MSH1 modulation in a crop species. We found that MSH1-mediated phenotypic variation in Sorghum bicolor …

Pengaruh Naungan Dan Konsentrasi Pupuk Organik Cair Terhadap Pertumbuhan Tanaman Anggrek Phalaenopsis Hasil Persilangan Kultivar Sayukudion X Taida Snow, Yayat Rochayat Suradinata

Jurnal Kultivasi

Percobaan ini bertujuan untuk menentukan persentase naungan dan konsentrasi pupuk organik cair yang terbaik terhadap pertumbuhan dan perkembangan tanaman anggrek Phalaenopsis hasil persilangan kultivar Sayukudion x Taida Snow. Dilaksanakan di Rumah Kaca Fakultas Pertanian Universitas Padjadjaran, Jatinangor, Sumedang, dengan ketinggian tempat 700 meter dpl, pada bulan Oktober 2011 sampai Januari 2012. Rancangan percobaan yang digunakan adalah Rancangan Petak Terbagi dengan dua faktor dan tiga ulangan. Petak utama adalah persentase naungan (55 %, 65 %, 75 %) dan anak petak adalah konsentrasi pupuk organik cair (1 ml L-1, 2 ml L-1, 3 ml L-1). Perlakuan persentase naungan dan konsentrasi pupuk organik …

Influence Of Ultraviolet Radiation On Cell Wall Constituents In Reduced-Lignin Mutants Of Corn And Sorghum, Brock Bermel

Undergraduate Research Symposium

Brown midrib mutants (BMR) of corn (Zea mays) and sorghum (Sorghum bicolor) have reduced lignin content and have recently gained popularity in Southern Minnesota as forage material for grazing animals. These mutants have lowered expression of cinnamyl alcohol dehydrogenase and caffeic O-methyltransferase enzymes in the phenylpropanoid pathway responsible for the construction of the cinnamyl alcohol subunits of lignin. Lignin is found in the secondary cell wall of higher plants, along with substantial amounts of cellulose and hemicellulose polysaccharides. Reduced lignin increases livestock digestibility of these plants, but may also increase susceptibility to environmental stress and lodging. …

Characterization Of Microorganisms From Alfalfa Seeds Inoculants, Benedicte Diatta, Kalianna Kennoy, Silvia Rossbach

Research and Creative Activities Poster Day

Atmospheric nitrogen fixation can be accomplished by free living microorganisms or by symbiosis between legume plants and rhizobia. The symbiosis between the alfalfa plant and Sinorhizobium meliloti is one example of the symbiotic relationship between legume plants and rhizobia. During the symbiosis, the rhizobia fix nitrogen for the plant and the plant in return provides carbohydrates for the bacteria. In order to maximize the plant’s yield in agriculture, recent technologies used include seed inoculants. Seed inoculation methods rely on coating the seeds with plant-growth promoting bacteria. Besides nitrogen-fixing bacteria, the seeds may also be coated with microorganisms aiding in mineral …

Qtl Architecture Of Reproductive Fitness Characters In Brassica Rapa, Jennifer M. Dechaine, Marcus T. Brock, Cynthia Weinig

All Faculty Scholarship for the College of the Sciences

Background

Reproductive output is critical to both agronomists seeking to increase seed yield and to evolutionary biologists interested in understanding natural selection. We examine the genetic architecture of diverse reproductive fitness traits in recombinant inbred lines (RILs) developed from a crop (seed oil) × wild-like (rapid cycling) genotype of Brassica rapa in field and greenhouse environments.

Results

Several fitness traits showed strong correlations and QTL-colocalization across environments (days to bolting, fruit length and seed color). Total fruit number was uncorrelated across environments and most QTL affecting this trait were correspondingly environment-specific. Most fitness components were positively correlated, consistent with life-history …

Unprecedented Heterogeneity In The Synonymous Substitution Rate Within A Plant Genome, Andan Zhu, Wenhu Guo, Kanika Jain, Jeffrey P. Mower

Center for Plant Science Innovation: Faculty Publications

The synonymous substitution rate varies widely among species, but it is generally quite stable within a genome due to the absence of strong selective pressures. In plants, plastid genes tend to evolve faster than mitochondrial genes, rate variation among species generally correlates between the mitochondrial and plastid genomes, and few examples of intragenomic rate heterogeneity exist. To study the extent of substitution rate variation between and within plant organellar genomes, we sequenced the complete mitochondrial and plastid genomes from the bugleweed, Ajuga reptans, which was previously shown to exhibit rate heterogeneity for several mitochondrial genes. Substitution rates were accelerated specifically …

Evaluation Of Constitutive Iron Reductase (Atfro2) Expression On Mineral Accumulation And Distribution In Soybean (Glycine Max. L), Marta W. Vasconcelos, Thomas E. Clemente, Michael A. Grusak

Center for Plant Science Innovation: Faculty Publications

Iron is an important micronutrient in human and plant nutrition. Adequate iron nutrition during crop production is central for assuring appropriate iron concentrations in the harvestable organs, for human food or animal feed. The whole-plant movement of iron involves several processes, including the reduction of ferric to ferrous iron at several locations throughout the plant, prior to transmembrane trafficking of ferrous iron. In this study, soybean plants that constitutively expressed the AtFRO2 iron reductase gene were analyzed for leaf iron reductase activity, as well as the effect of this transgene's expression on root, leaf, pod wall, and seed mineral concentrations. …

Identification Of Rna Silencing Components In Soybean And Sorghum, Xiang Liu, Tao Lu, Yongchao Dou, Bin Yu, Chi Zhang

Center for Plant Science Innovation: Faculty Publications

Background: RNA silencing is a process triggered by 21–24 small RNAs to repress gene expression. Many organisms including plants use RNA silencing to regulate development and physiology, and to maintain genome stability. Plants possess two classes of small RNAs: microRNAs (miRNAs) and small interfering RNAs (siRNAs). The frameworks of miRNA and siRNA pathways have been established in the model plant, Arabidopsis thaliana (Arabidopsis).

Results: Here we report the identification of putative genes that are required for the generation and function of miRNAs and siRNAs in soybean and sorghum, based on knowledge obtained from Arabidopsis. The gene families, including …

Methylation Protects Micrornas From An Ago1- Associated Activity That Uridylates 5′ Rna Fragments Generated By Ago1 Cleavage, Guodong Ren, Meng Xie, Shuxin Zhang, Carissa Vinovskis, Xuemei Chen, Bin Yu

Center for Plant Science Innovation: Faculty Publications

In plants, methylation catalyzed by HEN1 (small RNA methyl transferase) prevents microRNAs (miRNAs) from degradation triggered by uridylation. Howmethylation antagonizes uridylation of miRNAs in vivo is not well understood. In addition, 5′ RNA fragments (5′ fragments) produced by miRNA-mediated RNA cleavage can be uridylated in plants and animals. However, the biological significance of this modification is unknown, and enzymes uridylating 5′ fragments remain to be identified. Here, we report that in Arabidopsis, HEN1 suppressor 1 (HESO1, a miRNA nucleotidyl transferase) uridylates 5′ fragments to trigger their degradation.We also show that Argonaute 1 (AGO1), the effector protein of miRNAs, interacts …

Small Rnas Meet Their Targets: When Methylation Defends Mirnas From Uridylation, Guodong Ren, Xuemei Chen, Bin Yu

Center for Plant Science Innovation: Faculty Publications

Small RNAs are incorporated into Argonaute protein-containing complexes to guide the silencing of target RNAs in both animals and plants. The abundance of endogenous small RNAs is precisely controlled at multiple levels including transcription, processing and Argonaute loading. In addition to these processes, 3' end modification of small RNAs, the topic of a research area that has rapidly evolved over the last several years, adds another layer of regulation of their abundance, diversity and function. Here, we review our recent understanding of small RNA 3' end methylation and tailing.

Phenotypic Variation In Native North American And Invasive Chinese Populations Of Plantago Virginica, Teresa E. Popp

College of Graduate Studies: Theses & Dissertations

Alien plant species can cause significant economic and biological destruction by invading new environments and outcompeting native species. Through experimental research, the mechanisms by which these species invade can be better understood and applied to their management. Plantago virginica is a perennial herb, native to North America that has recently invaded China. It has been known to reduce crop growth and harbor diseases in the introduced range. A common garden study was conducted at the Georgia Southern University greenhouse, comparing twenty populations of P. virginica from both the native North American and invasive Chinese ranges. I examined if there were …

Molecular And Biochemical Mechanisms Of Pathogenesis In The Maize Foliar Pathogen Cercospora Zeae-Maydis, Winfred-Peck Dorleku

Graduate Theses and Dissertations

GLS is a serious foliar disease of maize, a major staple crop grown commercially in the USA for both human and animal feed production, and increasingly, for ethanol production. The disease is caused by two Cercospora species, C. zeae-maydis and C. zeina, both of which infect maize in the USA and in other parts of the world, with yield losses potentially greater than 50%, depending on local conditions. In culture, C. zeae-maydis produces a phytotoxic, host non-specific perylenequinone, cercosporin, and abscisic acid (ABA), for which there is no known pathological or physiological function in the fungus. Experimental evidence indicates …

Arabidopsis 56–Amino Acid Serine Palmitoyltransferase- Interacting Proteins Stimulate Sphingolipid Synthesis, Are Essential, And Affect Mycotoxin Sensitivity, Athen N. Kimberlin, Saurav Majumder, Gongshe Han, Ming Chen, Rebecca E. Cahoon, Julie M. Stone, Teresa M. Dunn, Edgar B. Cahoon

Center for Plant Science Innovation: Faculty Publications

Maintenance of sphingolipid homeostasis is critical for cell growth and programmed cell death (PCD). Serine palmitoyltransferase (SPT), composed of LCB1 and LCB2 subunits, catalyzes the primary regulatory point for sphingolipid synthesis. Small subunits of SPT (ssSPT) that strongly stimulate SPT activity have been identified in mammals, but the role of ssSPT in eukaryotic cells is unclear. Candidate Arabidopsis thaliana ssSPTs, ssSPTa and ssSPTb, were identified and characterized. Expression of these 56–amino acid polypeptides in a Saccharomyces cerevisiae SPT null mutant stimulated SPT activity from the Arabidopsis LCB1/LCB2 heterodimer by >100-fold through physical interaction with LCB1/LCB2. ssSPTa transcripts were …

Dynamic Expression Of Imprinted Genes Associates With Maternally Controlled Nutrient Allocation During Maize Endosperm Development, Mingming Xin, Ruolin Yang, Guosheng Li, Hao Chen, John Laurie, Chuang Ma, Dongfang Wang, Yingyin Yao, Brian A. Larkins, Qixin Sun, Ramin Yadegari, Xiangfeng Wang, Zhongfu Ni

Center for Plant Science Innovation: Faculty Publications

In angiosperms, the endosperm provides nutrients for embryogenesis and seed germination and is the primary tissue where gene imprinting occurs. To identify the imprintome of early developing maize (Zea mays) endosperm, we performed highthroughput transcriptome sequencing of whole kernels at 0, 3, and 5 d after pollination (DAP) and endosperms at 7, 10, and 15 DAP, using B73 byMo17reciprocal crosses.Weobserved gradually increased expression of paternal transcripts in 3- and 5-DAP kernels. In 7-DAP endosperm, the majority of the genes tested reached a 2:1 maternal versus paternal ratio, suggesting that paternal genes are nearly fully activated by 7 DAP. …

Plant Micrornas Display Differential 3' Truncation And Tailing Modifications That Are Argonaute1 Dependent And Conserved Across Species, Jixian Zhai, Yuanyuan Zhao, Stacey A. Simon, Sheng Huang, Katherine Petsch, Siwaret Arikit, Manoj Pillay, Lijuan Ji, Meng Xie, Xiaofeng Cao, Bin Yu, Marja Timmermans, Bing Yang, Xuemei Chen, Blake C. Meyers

Center for Plant Science Innovation: Faculty Publications

Plant small RNAs are 3' methylated by the methyltransferase HUA1 ENHANCER1 (HEN1). In plant hen1 mutants, 3' modifications of small RNAs, including oligo-uridylation (tailing), are associated with accelerated degradation of microRNAs (miRNAs). By sequencing small RNAs of the wild type and hen1 mutants from Arabidopsis thaliana, rice (Oryza sativa), and maize (Zea mays), we found 39 truncation prior to tailing is widespread in these mutants. Moreover, the patterns of miRNA truncation and tailing differ substantially among miRNA families but are conserved across species. The same patterns are also observable in wild-type libraries from a broad …

Functional Annotation, Transcriptional Characterization And Enzymatic Contributions Of Essential Amino Acid Biosynthesis-Related Genes, Teresa J. Clark

Masters Theses

In plants, essential amino acid biosynthesis predominantly or exclusively occurs in the plastid. The plastid in the heterokont alga Nannochloropsis oceanica is surrounded by four membranes, which add great complexity to intracellular trafficking and communication. N. oceanica genes in essential amino acid biosynthesis were functionally annotated. The biosynthesis pathways resemble the pathways in Arabidopsis thaliana, but the gene content seems to be simpler in N. oceanica.

In addition, two A. thaliana mutants with loss-of-function mutations in the aspartate kinase-homoserine dehydrogenase 2 (AK-HSDH2) gene were characterized. These ak-hsdh2 mutants demonstrate unexpected accumulation of aspartate-derived amino acids (ADAAs), particularly threonine, in …

Genetic Diversity Of Seed Dormancy And Molecular Evolution Of Weedy Red Rice, Te Ming Tseng

Graduate Theses and Dissertations

Rice is the grain with the third-highest global production. In the US, Arkansas is the largest rice producing state; however, an estimated 62% of the rice fields in the state are infested with red rice, and can cause up to 80% yield reduction in rice. Among its weedy traits, seed dormancy plays an important role in its persistence, and helps red rice escape weed management techniques thereby increasing the red rice soil seedbank. Red rice also has the potential to hybridize among themselves and with cultivated rice, thus resulting in diverse phenotypes and genotypes. In this study we measured variation …

Pseudomonas Hopu1 Modulates Plant Immune Receptor Levels By Blocking The Interaction Of Their Mrnas With Grp7, Valerie Nicaise, Anna Joe, Byeong-Ryool Jeong, Christin Korneli, Freddy Boutrot, Isa Westedt, Dorothee Staiger, James R. Alfano, Cyril Zipfel

Center for Plant Science Innovation: Faculty Publications

Pathogens target important components of host immunity to cause disease. The Pseudomonas syringae type III-secreted effector HopU1 is a mono-ADP-ribosyltransferase required for full virulence on Arabidopsis thaliana. HopU1 targets several RNA-binding proteins including GRP7, whose role in immunity is still unclear. Here, we show that GRP7 associates with translational components, as well as with the pattern recognition receptors FLS2 and EFR. Moreover, GRP7 binds specifically FLS2 and EFR transcripts in vivo through its RNA recognition motif. HopU1 does not affect the protein–protein associations between GRP7, FLS2 and translational components. Instead, HopU1 blocks the interaction between GRP7 and FLS2 and …

Small Interfering Rna–Mediated Translation Repression Alters Ribosome Sensitivity To Inhibition By Cycloheximide In Chlamydomonas Reinhardtii, Xinrong Ma, Eun-Jeong Kim, Insun Kook, Fangrui Ma, Adam Voshall, Etsuko N. Moriyama, Heriberto D. Cerutti

Center for Plant Science Innovation: Faculty Publications

Small RNAs (sRNAs; approximately 20 to 30 nucleotides in length) play important roles in gene regulation as well as in defense responses against transposons and viruses in eukaryotes. Their biogenesis and modes of action have attracted great attention in recent years. However, many aspects of sRNA function, such as the mechanism(s) of translation repression at postinitiation steps, remain poorly characterized. In the unicellular green alga Chlamydomonas reinhardtii, sRNAs derived from genomeintegrated inverted repeat transgenes, perfectly complementary to the 39 untranslated region of a target transcript, can inhibit protein synthesis without or with only minimal mRNA destabilization. Here, we report …

Complementarity To An Mirna Seed Region Is Sufficient To Induce Moderate Repression Of A Target Transcript In The Unicellular Green Alga Chlamydomonas Reinhardtii, Tomohito Yamasaki, Adam Voshall, Eun-Jeong Kim, Etsuko N. Moriyama, Heriberto Cerutti, Takeshi Ohama

Center for Plant Science Innovation: Faculty Publications

MicroRNAs (miRNAs) are 20–24 nt noncoding RNAs that play important regulatory roles in a broad range of eukaryotes by pairing with mRNAs to direct post-transcriptional repression. The mechanistic details of miRNA-mediated post-transcriptional regulation have been well documented in multicellular model organisms. However, this process remains poorly studied in algae such as Chlamydomonas reinhardtii, and specific features of miRNA biogenesis, target mRNA recognition and subsequent silencing are not well understood. In this study, we report on the characterization of a Chlamydomonas miRNA, cre-miR1174.2, , which is processed from a near-perfect hairpin RNA. Using Gaussia luciferase (gluc) reporter genes, …

Camelina Seed Transcriptome: A Tool For Meal And Oil Improvement And Translational Research, Huu T. Nguyen, Jillian E. Silva, Ram Podicheti, Jason Macrander, Wenyu Yang, Tara J. Nazarenus, Jeong-Won Nam, Jan G. Jaworski, Chaofu Lu, Brian E. Scheffler, Keithanne Mockaitis, Edgar B. Cahoon

Center for Plant Science Innovation: Faculty Publications

Camelina (Camelina sativa), a Brassicaceae oilseed, has received recent interest as a biofuel crop and production platform for industrial oils. Limiting wider production of camelina for these uses is the need to improve the quality and content of the seed protein-rich meal and oil, which is enriched in oxidatively unstable polyunsaturated fatty acids that are deleterious for biodiesel. To identify candidate genes for meal and oil quality improvement, a transcriptome reference was built from 2047 Sanger ESTs and more than 2 million 454-derived sequence reads, representing genes expressed in developing camelina seeds. The transcriptome of approximately 60K transcripts …

Comparative Analyses Of Two Geraniaceae Transcriptomes Using Next-Generation Sequencing, Jinxin Zhang, Tracey A. Ruhlman, Jeffrey P. Mower, Robert K. Jansen

Center for Plant Science Innovation: Faculty Publications

Background: Organelle genomes of Geraniaceae exhibit several unusual evolutionary phenomena compared to other angiosperm families including accelerated nucleotide substitution rates, widespread gene loss, reduced RNA editing, and extensive genomic rearrangements. Since most organelle-encoded proteins function in multi-subunit complexes that also contain nuclear-encoded proteins, it is likely that the atypical organellar phenomena affect the evolution of nuclear genes encoding organellar proteins. To begin to unravel the complex co-evolutionary interplay between organellar and nuclear genomes in this family, we sequenced nuclear transcriptomes of two species, Geranium maderense and Pelargonium x hortorum.

Results: Normalized cDNA libraries of G. maderense and …

Arabidopsis 56–Amino Acid Serine Palmitoyltransferase- Interacting Proteins Stimulate Sphingolipid Synthesis, Are Essential, And Affect Mycotoxin Sensitivity, Athen N. Kimberlin, Saurav Majumder, Gongshe Han, Ming Chen, Rebecca E. Cahoon, Julie M. Stone, Teresa M. Dunn, Edgar B. Cahoon

Center for Plant Science Innovation: Faculty Publications

Maintenance of sphingolipid homeostasis is critical for cell growth and programmed cell death (PCD). Serine palmitoyltransferase (SPT), composed of LCB₁ and LCB₂ subunits, catalyzes the primary regulatory point for sphingolipid synthesis. Small subunits of SPT (ssSPT) that strongly stimulate SPT activity have been identified in mammals, but the role of ssSPT in eukaryotic cells is unclear. Candidate Arabidopsis thaliana ssSPTs, ssSPTa and ssSPTb, were identified and characterized. Expression of these 56–amino acid polypeptides in a Saccharomyces cerevisiae SPT null mutant stimulated SPT activity from the Arabidopsis LCB₁/LCB₂ heterodimer by >100-fold through physical interaction with LCB …

Pseudomonas Syringae Pv. Syringae Uses Proteasome Inhibitor Syringolin A To Colonize From Wound Infection Sites, Johana C. Misas-Villamil, Izabella Kolodziejek, Emerson Crabill, Farnusch Kaschani, Sherry Niessen, Takayuki Shindo, Markus Kaiser, James R. Alfano, Renier A. L. Van De Hoorn

Center for Plant Science Innovation: Faculty Publications

Infection of plants by bacterial leaf pathogens at wound sites is common in nature. Plants defend wound sites to prevent pathogen invasion, but several pathogens can overcome spatial restriction and enter leaf tissues. The molecular mechanisms used by pathogens to suppress containment at wound infection sites are poorly understood. Here, we studied Pseudomonas syringae strains causing brown spot on bean and blossom blight on pear. These strains exist as epiphytes that can cause disease upon wounding caused by hail, sand storms and frost. We demonstrate that these strains overcome spatial restriction at wound sites by producing syringolin A (SylA), a …

Functional Modeling Identifies Paralogous Solanesyl-Diphosphate Synthases That Assemble The Side Chain Of Plastoquinone-9 In Plastids, Anna Block, Rikard Fristedt, Sara Rogers, Jyothi Kumar, Brian Barnes, Joshua Barnes, Christian Elowsky, Yashitola Wamboldt, Sally Ann Mackenzie, Kevin Redding, Sabeeha S. Merchant, Gilles J. Basset

Center for Plant Science Innovation: Faculty Publications

Background: Plastid isoforms of solanesyl-diphosphate synthase catalyze the elongation of the prenyl side chain of plastoquinone-9.

Results: Corresponding mutants display lower levels of plastoquinone-9 and plastochromanol-8 and display intact levels of vitamin E.

Conclusion: Plastochromanol-8 originates from a subfraction of non-photoactive plastoquinol-9 and is not essential for seed longevity.

Significance: Viable plastoquinone-9 mutants are invaluable tools for understanding plastid metabolism.

Mutational Analyses Of A Fork Head Associated Domain Protein, Dawdle, In Arabidopsis Thaliana, Lakshmi Ayiloor Narayanan, Dipaloke Mukherjee, Shuxin Zhang, Bin Yu, David Chevalier

Center for Plant Science Innovation: Faculty Publications

DAWDLE (DDL) gene encodes a protein that contains an N-terminal arginine-rich domain and a C-terminal Fork Head Associated (FHA) domain in Arabidopsis thaliana. DDL protein is believed to function in microRNA biogenesis by mediating the recruitment of pri-microRNA to DICER-LIKE 1 and also stabilizing the microRNA. The aim of this study was to conduct a structure-function analysis to identify the regions in DDL that are of functional significance. Targeted Induced Local Lesions in Genome screen was performed in the Columbia erecta-105 background of Arabidopsis resulting in the identification of eight point mutations spanning DDL. The mutants were characterized by …

Cdc5, A Dna Binding Protein, Positively Regulates Posttranscriptional Processing And/Or Transcription Of Primary Microrna Transcripts, Shuxin Zhang, Meng Xie, Guodong Ren, Bin Yu

Center for Plant Science Innovation: Faculty Publications

CDC5 is a MYB-related protein that exists in plants, animals, and fungi. In Arabidopsis, CDC5 regulates both growth and immunity through unknown mechanisms. Here, we show that CDC5 from Arabidopsis positively regulates the accumulation of microRNAs (miRNAs), which control many biological processes including development and adaptations to environments in plants. CDC5 interacts with both the promoters of genes encoding miRNAs (MIR) and the DNA-dependent RNA polymerase II. As a consequence, lack of CDC5 reduces the occupancy of polymerase II at MIR promoters, as well as MIR promoter activities. In addition, CDC5 is associated with the DICER–LIKE1 complex, …

Comparative Studies Of Differential Gene Calling Using Rna-Seq Data, Ximeng Zheng, Etsuko N. Moriyama

Center for Plant Science Innovation: Faculty Publications

Background: With its massive amount of data, gene-expression profiling by RNA-Seq has many advantanges compared with microarray experiments. RNA-Seq analysis, however, is fundamentally different from microarray data analysis. Techniques developed for analyzing microarray data thus cannot be directly applicable for the digital gene expression data. Several statistical methods have been developed for identifying differentially expressed genes specifically from RNA-Seq data over the past few years.
Results: In this study, we examined the performance of differential gene-calling methods using RNA-Seq data in practical situations. We focused on two representative methods: one parametric method, DESeq, and one nonparametric method, NOISeq. …

A Novel Function Prediction Approach Using Protein Overlap Networks, Shide Liang, Dandan Zheng, Daron M. Standley, Huarong Guo, Chi Zhang

Center for Plant Science Innovation: Faculty Publications

Background: Construction of a reliable network remains the bottleneck for network-based protein function prediction. We built an artificial network model called protein overlap network (PON) for the entire genome of yeast, fly, worm, and human, respectively. Each node of the network represents a protein, and two proteins are connected if they share a domain according to InterPro database.
Results: The function of a protein can be predicted by counting the occurrence frequency of GO (gene ontology) terms associated with domains of direct neighbors. The average success rate and coverage were 34.3% and 43.9%, respectively, for the test genomes, …

A Thraustochytrid Diacylglycerol Acyltransferase 2 With Broad Substrate Specificity Strongly Increases Oleic Acid Content In Engineered Arabidopsis Thaliana Seeds, Chunyu Zhang, Umidjon Iskandarov, Elliott T. Klotz, Robyn L. Stevens, Rebecca E. Cahoon, Tara J. Nazarenus, Suzette L. Pereira, Edgar B. Cahoon

Center for Plant Science Innovation: Faculty Publications

Diacylglycerol acyltransferase (DGAT) catalyses the last step in acyl-CoA-dependent triacylglycerol (TAG) biosynthesis and is an important determinant of cellular oil content and quality. In this study, a gene, designated TaDGAT2, encoding a type 2 DGAT (DGAT2)-related enzyme was identified from the oleaginous marine protist Thraustochytrium aureum. The deduced TaDGAT2 sequence contains a ~460 amino acid domain most closely related to DGAT2s from Dictyostelium sp. (45–50% identity). Recombinant TaDGAT2 restored TAG biosynthesis to the Saccharomyces cerevisiae H1246 TAG-deficient mutant, and microsomes from the complemented mutant displayed DGAT activity with C16 and C18 saturated and unsaturated fatty acyl-CoA and diacylglycerol …