Project description:We have generated over 80 million 32 nt reads generated from RNA samples isolated from the tip and base of a developing Mo17 leaf. A comparision of these data with the maize AGP resulted in the confirmation of approximately 88% of the maize filtered gene set Keywords: Transcriptome analysis
Project description:We have generated over 80 million 32 nt reads generated from RNA samples isolated from the tip and base of a developing Mo17 leaf. A comparision of these data with the maize AGP resulted in the confirmation of approximately 88% of the maize filtered gene set Keywords: Transcriptome analysis Examination of two different RNA samples from two different segments of a developing 3rd leaf
Project description:Constituting the final growth phase during the lifecycle of maize (Zea Mays L.), leaf senescence plays an important biological role in grain yield in crops. We undertook proteomic and physiological analyses in inbred line Yu816 in order to unravel the underlying mechanisms of leaf senescence induced by preventing pollination. A total of 6,941 proteins were identified by Isobaric tags for Relative and Absolute Quantitation (iTRAQ) analysis. Proteomic analyses between pollinated (POL) and non-pollinated (NONPOL) plants indicated that 973 different proteins accumulated in NONPOL plants. The accumulated proteins were classified into various groups, including response to stimuli, cellular processes, cell death and metabolic processes using functional analysis. Furthermore, in accordance with the changes in these different accumulated proteins, analysis of changes in leaf total soluble sugars and starch content showed that the prevention of pollination can disturb endogenousplant hormone and sugar metabolism and lead to ROS bursts, protein degradation and photosystem breakdown, eventually resulting in leaf senescence. This represents the first attempt at global proteome profiling in response to induced leaf senescence by preventing pollination in maize, and provides a better understanding of the molecular mechanisms involved in induced leaf senescence.Constituting the final growth phase during the lifecycle of maize (Zea Mays L.), leaf senescence plays an important biological role in grain yield in crops. We undertook proteomic and physiological analyses in inbred line Yu816 in order to unravel the underlying mechanisms of leaf senescence induced by preventing pollination. A total of 6,941 proteins were identified by Isobaric tags for Relative and Absolute Quantitation (iTRAQ) analysis. Proteomic analyses between pollinated (POL) and non-pollinated (NONPOL) plants indicated that 973 different proteins accumulated in NONPOL plants. The accumulated proteins were classified into various groups, including response to stimuli, cellular processes, cell death and metabolic processes using functional analysis. Furthermore, in accordance with the changes in these different accumulated proteins, analysis of changes in leaf total soluble sugars and starch content showed that the prevention of pollination can disturb endogenousplant hormone and sugar metabolism and lead to ROS bursts, protein degradation and photosystem breakdown, eventually resulting in leaf senescence. This represents the first attempt at global proteome profiling in response to induced leaf senescence by preventing pollination in maize, and provides a better understanding of the molecular mechanisms involved in induced leaf senescence.
Project description:Maize husk leaf - the outer leafy layers covering the ear - modulates kernel yield and quality. Despite its importance, however, the genetic controls underlying husk leaf development remain elusive. Our previous genome-wide association study identified a single nucleotide polymorphism located in the gene RHW1 (Regulator of Husk leaf Width) that is significantly associated with husk leaf-width diversity in maize. Here, we further demonstrate that a polymorphic 18-bp InDel (insertion/deletion) variant in the 3' untranslated region of RHW1 alters its protein abundance and accounts for husk leaf width variation. RHW1 encodes a putative MYB-like transcriptional repressor. Disruption of RHW1 altered cell proliferation and resulted in a narrower husk leaf, whereas RHW1 overexpression yielded a wider husk leaf. RHW1 positively regulated the expression of ZCN4, a well-known TFL1-like protein involved in maize ear development. Dysfunction of ZCN4 reduced husk leaf width even in the context of RHW1 overexpression. The InDel variant in RHW1 is subject to selection and is associated with maize husk leaf adaption from tropical to temperate regions. Overall, our results identify that RHW1-ZCN4 regulates a pathway conferring husk leaf width variation at a very early stage of husk leaf development in maize.
Project description:To investigate the developmental gradient of the third maize leaf, the light exposed area of the leaf (corresponding to 18cm of leaf) and 2cm shaded by the sheath were sampled in ten slices. Four replicates were collected, immediately shock frozen in liquid nitrogen and subsequently cut into 2cm slices. At least 10 plants were pooled for each biological replicate. We have systematically analyzed a developmental gradient of the third maize leaf from the point of emergence into the light to the tip in ten continuous leaf slices to study organ development and physiological and biochemical functions. Transcriptome analysis, oxygen sensitivity of photosynthesis, delta-13C values, and photosynthetic rate measurements showed that the maize leaf undergoes a sink to source transition without an intermediate phase of C3 photosynthesis or operation of a photorespiratory carbon pump. Metabolome and transcriptome analysis, chlorophyll and protein measurements, as well as dry weight determination showed continuous gradients for all analyzed items. The absence of binary on-off switches and regulons pointed to a morphogradient along the leaf as the determining factor of developmental stage. Analysis of transcription factors for differential expression along the leaf gradient defined a list of putative regulators orchestrating the sink-to-source transition and establishment of C4 photosynthesis. Finally, transcriptome and metabolome analysis, as well as enzyme activity measurements, and absolute quantification of selected metabolites revised the current model of maize C4 photosynthesis. All datasets are included within the publication to serve as a resource for maize leaf systems biology. For the transcriptional analysis, the goal of the study was to (i) identify whether the leaf contains binary switches for genes involved in photosynthesis, (ii)characterize the patterns of gene expression in the leaf, (iii) provide independent validation of maize leaf expression experiments published in Li et al. (2011) and (iv) determine transcripts co-expressed with key transcripts of C4 photosynthesis. To this end, changed transcripts were determined by ANOVA and characterized by K-means and hierachical clustering.
Project description:Genotype and nitrogen-dosage effect on maize leaves collected at V8 leaf stage B73 is a model maize genotype while Illinois high protein line (IHP) is a metabolic extreme selected for higher grain protein concentration. It is a well known fact that the leaves serve as source and earshoot as a sink. Microarray analysis of V8 leaf collected from B73 and IHP genotypes grown at vairable nitrogen applications. Keywords: Genotype and N-treatment response