Project description:Chlorophyll plays critical roles in photosynthetic light harvesting, energy transduction and plant development. In this study, a novel wucai (Brassica campestris L.) germplasm with green outer leaves and yellow inner leaves at the adult stage (W7-2) was used to examine chlorophyll metabolism response to cold acclimation. A green leaf wucai genotype without leaf color changes named W7-1 was selected as the control to evaluate the chlorophyll metabolism changes of W7-2. Compared to W7-1, the contents of chlorophyll a (Chl a) and chlorophyll b (Chl b) in W7-2 were significantly reduced at five developmental stages (13, 21, 29, 37 and 45 days after planting (DAP). An iTRAQ-based quantitative proteomic analysis was carried out at 21 and 29 DAP according to the leaf color changes in both of genotypes. A total of 1409 proteins were identified, of which 218 showed differential accumulations between W7-2 and W7-1 during the two developmental stages.
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:rs12-07_pnm1 - leaf transcriptome comparison between wt and pnm1dnls plants - Identification of nuclear genes regulated by PNM1 (At5g60960) in Arabidopsis thaliana. Mature rosettte leaf transcriptomes were compared between WT and PNM1DNLS mutants. 3 dye-swap - normal vs transgenic comparaison
Project description:We study differences in gene expression between Populus P35S::BL (BL-oe) lines and control, affecting plant growth and differentiation, and dormancy. We used microarrays to detail the global program of gene expression underlying morphological and developmental changes droved by overexpression of BL gene. We identified an activation tagging mutant with increased leaf size and correspondingly name it BIG LEAF (BL). We positioned the tag, localized a putative candidate gene and verified transcription activation. The activated gene encodes a WD40 putative transcription regulator similar to the Arabidopsis thaliana STERILE APETALA (SAP). We recapitulated the phenotype by overexpression of the gene into the same genotype under strong constitutive promoter (P35S::BL, BL-oe). Transgenic up-regulation of the BL gene caused enhanced leaf size, early bud-break, and suppression of secondary growth. BL transcript abundance in wild type plants is in apical tissues, mostly in shoot meristem, leaf primordia and axillary meristem. Our data indicates that BL plays an important role in the process of tree growth. Poplar apex, secondary stem (30th internode), and leaves (at 30 node) was selected for RNA extraction and hybridization on Affymetrix microarrays. We sought to obtain expression of affected genes in P35S::BL lines and control wild type (WT-717), in order to increase the resolution of expression profiles inducing the developmental changes in P35S::BL. To do that, we selected apex, stem and leaf tissue from greenhouse healthy plants.
Project description:To get deeper insights into the GSH-triggered systemic defense signaling events in plants, we performed transcriptome profiling on leaf 6 collected after one hour application of GSH to leaf 1 of WT plants. To further investigate the relations between GSH and Glu in plant wound response, we generated transcriptome data sets from leaf 6 one hour after wounding leaf 1 or application of Glu to leaf 1 of WT plants.
Project description:To understand the drought responsive mechanisms and the harmful effects of stress, it is necessary to develop drought tolerant genotype. In this study, drought-sensitive and -tolerant fennel genotypes were selected. Using these materials, a gel-free/label-free proteomic technique was performed to identify responsive proteins in fennel leaf under drought stress
Project description:Switchgrass (Panicum virgatum) is a perennial crop producing deep roots thus highly tolerant to soil water deficit conditions. However, seedling establishment in field is very susceptible to prolonged and periodic drought stress. In this study, a “sandwich” system simulating a gradual water deletion process was developed. Switchgrass seedlings were subjected to a 20-day gradual drought treatment process when soil water tension was increased to 0.05 MPa (moderate drought stress) and leaf physiological properties had expressed significant alteration. Drought-induced changes in leaf proteomes were identified using the relative and absolute quantitation (iTRAQ) labeling method followed by nano-scale liquid chromatography mass spectrometry (nano-LC-MS/MS) analysis. Additionally, total leaf proteins were processed using a combinatorial library of peptide ligands to enrich for lower abundance proteins. Both total proteins and those enriched samples were analyzed to increase the coverage of the quantitative proteomics analysis. A total of 7,006 leaf proteins were identified, and 257 (4% of the leaf proteome) expressed a significant difference (P < 0.05, fold change < 0.6 or > 1.7) from the non-treated control to drought-treated conditions. Results from this study, in addition to revealing molecular responses to drought stress, provide a large number of proteins (candidate genes) that can be employed to improve switchgrass seedling growth and establishment under soil drought condition.
Project description:To stabilize crop yield under low temperature stress conditions, it is important to improve stress tolerance in crops. Upon exposure to low temperature stress, many genes are induced and their products are thought to function as cellular protectants of stress-induced damages Therefore, responses of global gene expression profiles to cold stress was analyzed at the booting stage using the 60K Rice Whole Genome Microarray. The cold-tolerant rice variety, Stejaree45 was transplanted in 1/5000 pot at 20 days after seeding. Fertilizers were applied at the rate of 11, 7.7 and 9.3 kg/10a in N, P2O5 The samples were selected at the booting stage of rice on the basis of the auricle distance (the distance between auricles of flag leaf and the previous leaf of the main culm). The plants with an auricle distance ranging from -5 ㎝ to 0 ㎝ were exposed up to the flag leaf auricle using cold water (13℃) for 3 days. Glumous flowers and flag leaves of the cold-resistant variety, Stejaree45, were used to examine gene expression profiles.
Project description:The metabolic response of maize source leaves to low nitrogen supply was analyzed in maize seedlings by parallel measurements of transcriptome and metabolome profiling. Inbred lines A188 and B73 were cultivated under controlled growth chamber conditions and supplied with either sufficient (15mM) or limiting (0.15mM) nitrate supply. Leaf lamina material was harvested at day 20 and day 30 after germination with the fifth and sixth leaf representing the main source leaf respectively. Four replicates were collecetd from individual plants for each combination of genotype, growth stage and nitrogen treatment. The leaf material was frozen, homogenised and aliquoted for transcriptome and metabolome analysis. The molecular data was further supplemented by phenotypic characterisation of the maize seedlings under investigation. Limited availability of nitrogen caused strong shifts in the metabolite profile of leaves. The transcriptome was less affected by the nitrogen stress but showed strong genotype and age dependent patterns. Nitrogen starvation initiated the selective down-regulation of processes involved in nitrate reduction and amino acid assimilation; ammonium assimilation related transcripts on the other hand were not influenced. Carbon assimilation related transcripts were characterized by high transcriptional coordination and general down-regulation under low nitrogen conditions. Nitrogen deprivation caused a slight accumulation of starch, but also directed increased amounts of carbohydrates into the cell wall and secondary metabolites. The decrease in N availability also resulted in accumulation of phosphate and by strong down-regulation of genes usually involved in phosphate starvation response, underlining the great importance of phosphate homeostasis control under stress conditions. Maize inbred lines A188 and B73 were cultivated in pots containing nutrient poor peat soil under the controlled conditions of a growth chamber. The plants were fertilized with modified Hoagland solutions containing either 15mM (high N) or 0.15mM nitrate (low N). Source leaf lamina were harvested at day 20 and day 30 after start of germination for parallel analysis of transcriptome and metabolome profiles. The molecular data is further supplemented by phenotypic characterization of the maize seedlings under investigation.
Project description:To study genes specially expressed in root tip, leaf tip, shoot tip, root (without root tip) and leaf (without leaf tip) of Ceratopteris richardii, we carried out an RNA-seq to analyze gene expression levels from these five tissues.