Project description:Many animal and plant species exhibit increased growth rates, reach larger sizes and, in the cases of crops and farm animals, produce higher yields when bred as hybrids between genetically differing strains, a phenomenon known as hybrid vigour or heterosis. Despite the importance of heterosis, and its extensive genetic analysis, there has been little understanding of its molecular basis. We aimed to determine whether characteristics of the leaf transcriptome, as an indicator of the innate functional genetic architecture of a plant line, could be used as markers to predict heterosis and the performance of hybrids, a methodology we term Association Transcriptomics. Relationships between transcript abundance of specific genes and the values of heterosis and heterosis-dependent traits were identified and mathematical models were constructed that relate gene expression characteristics in inbred lines of Arabidopsis thaliana and maize with vegetative biomass and for grain yield, respectively, in corresponding hybrids.
Project description:Comparative proteomics of ER-Golgi membranes from etiolated coleoptiles of maize (Zea mays) and young leaves of Arabidopsis (Arabidopsis thaliana) isolated by flotation centrifugation demonstrate differences in the complement of synthases and glycosyl transferases unique to the type of wall made. Additionally, maize Golgi membranes enriched by flotation were separated further by free-flow electrophoresis (FFE), yielding 3009 proteins, of which 229 were known to function in cell wall synthesis or metabolism. A subset of proteins identified after flotation centrifugation were identified in Golgi membranes but failed to enrich in them. Individual classes of proteins associated with cell wall synthesis were asymmetrically distributed across the fractions of Golgi membranes separated by FFE.
Project description:Many animal and plant species exhibit increased growth rates, reach larger sizes and, in the cases of crops and farm animals, produce higher yields when bred as hybrids between genetically differing strains, a phenomenon known as hybrid vigour or heterosis. Despite the importance of heterosis, and its extensive genetic analysis, there has been little understanding of its molecular basis. We aimed to determine whether characteristics of the leaf transcriptome, as an indicator of the innate functional genetic architecture of a plant line, could be used as markers to predict heterosis and the performance of hybrids, a methodology we term Association Transcriptomics. Relationships between transcript abundance of specific genes and the values of heterosis and heterosis-dependent traits were identified and mathematical models were constructed that relate gene expression characteristics in inbred lines of Arabidopsis thaliana and maize with vegetative biomass and for grain yield, respectively, in corresponding hybrids. Plants used for transcriptome analysis were grown from seeds for 2 weeks. Aerial parts above the coleoptiles were excised, weighed and frozen in liquid nitrogen. All plants were harvested as close as practicable to the middle of the photoperiod. Plants used for transcriptome analysis were grown from seeds for 2 weeks. Maize seeds were first imbibed in distilled water for 2 days in glasshouse conditions to break dormancy, before transfer to peat and sand P7 pots. They were grown in long day glass house conditions (16 hours photoperiod) at 22 degrees Celsius. Aerial parts above the coleoptiles were excised, weighed and frozen in liquid nitrogen. All plants were harvested as close as practicable to the middle of the photoperiod. Plants for yield trials were grown in the field at Clayton, NC, U.S.A. in 2005. Forty plants of each hybrid were grown in duplicate 0.0007 hectare plots.
Project description:The focus of this study was to identify changes in host gene expression induced by the transcription-dependent function of the viral AC2 protein, and induced by the interaction of AC2/C2 with SnRK1.2 (AtAKIN11). We used microarrays to identify changes in host gene expression induced by the transcription-dependent function of the geminivirus-encoded AC2 protein, and induced by the interaction of AC2 with a host serine-threonine kinase, SnRK1. Distinct classes of genes were up- and down regulated during this process. For experiment 1, Arabidopsis rosette leaves were infused with Agrobacterium capable of expressing full-length Cabbage leaf curl virus (CaLCuV) AC2 protein, a truncated version of AC2 lacking the C-terminal 29 amino acids (AC2del), or an empty vector control (530). In experiment 2, Arabidopsis rosette leaves were infused with Agrobacterium capable of expressing full-length Spinach curly top virus C2 protein, a truncated version of C2 lacking the C-terminal 29 amino acids (C2del), antisense (as) SnRK1.2 (AsAKIN11), or an empty vector control (530).
Project description:Maize (Zea mays L.) is one of the major cereal crops worldwide. Increasing planting density is an effective way to improve crop yield. However, plants grown under high-density conditions compete for water, nutrients, and light, which often leads to changes in productivity. To date, few studies have determined the transcriptomic differences in maize leaves in response to different planting densities. This study examined the whole-genome expression patterns in the leaves of maize planted under high and low densities to identify density-regulated genes. Leaves at upper, ear, and lower stem nodes were collected at the grain-filling stage of the maize hybrid Xianyu335 grown under low-density planting and high-density planting. In total, 72, 733, and 1,739 differentially expressed genes (DEGs) were identified in the respective upper, ear, and lower leaves under HDP. Upregulated and downregulated DEGs in the upper and lower leaves were similar in number, whereas upregulated DEGs in the ear leaves were significantly higher in number than the downregulated DEGs. Functional analysis indicated that genes responding to HDP-related stresses were mediated by pathways involving four phytohormones responsible for metabolism and signaling, osmoprotectant biosynthesis, transcription factors, and fatty acid biosynthesis and protein kinases, which suggested that these pathways are affected by the adaptive responses mechanisms underlying the physiological and biochemical responses of the leaves of maize planted at high density.
Project description:Head smut of maize, which is caused by the Sporisorium reilianum f. sp. Zeae (Kühn), has been a serious disease in maize. In order to find head smut resistant candidate genes, microarrays were used to monitor the gene expression profiles between disease resistant near isogenic lines (NIL) L282 and L43, highly resistant inbred line Q319 and highly susceptible inbred line Huangzao4 after 0 to7 days post inoculation of S.reiliana by artificial inoculation method. Maize leaves were selected at 0d, 1d, 2d, 4d, 7d post inoculation for RNA extraction and hybridization on Affymetrix microarrays. We sought to obtain different expression genes of different varieties at each inoculation stage in order to find head smut resistant candidate genes.
Project description:Brevicompanines are natural products isolated from the culture filtrate of the fungus Penicillium brevicompactum. They showed plant growth regulating properties in several species including lettuce, rice or Arabidopsis thaliana. We used microarrays to gather information about the reprogramming of gene transcription when Arabidopsis leaves were treated with Brevicompanine C (BrvC) that showed significant activity in plant growth assays.
Project description:To understand plant adaptation to heat stress, gene expression profiles of Arabidopsis leaves under heat stress, during recovery and control condition were obtained using microarray. Microarray data listed responsible candidate genes for glycerolipid metabolism.
Project description:Cytokinins are plant hormones with biological functions ranging from coordination of plant growth and development to the regulation of senescence. A series of 2-chloro-N6-(halogenobenzylamino)purine ribosides was prepared and tested for cytokinin activity in selected bioassays. Several compounds showed significant activity, especially in delaying senescence in detached wheat leaves. We used microarrays to gather information about the reprogramming of gene transcription when senescent Arabidopsis leaves were treated with selected C2-substituted aromatic cytokinin ribosides that showed high activity in the senescence bioassay.