Project description:To provide a global study of transcriptome changes under drought stress, the gene expression levels of a durum wheat genotype (Triticum durum Desf. cultivar Creso) and two bread wheat genotypes (Triticum aestivum L. cultivar Chinese Spring -CS- and its deletion line CS_5AL-10) were investigated. The 5A chromosome deletion line (5AL-10) lacks the distal part (43%) of the long arm of chromosome 5A. Each genotype was subjected to two different levels of water stress at the grain filling stage. After anthesis, three different levels of soil water content (SWC) were induced as described below: control (CTRL; SWC=28%), moderate stress (MS; SWC=18%), and severe stress (SS; SWC=12.5%). For each sample, three biological replicates were performed, for a total of 27 hybridizations. ****[PLEXdb(http://www.plexdb.org) has submitted this series at GEO on behalf of the original contributor, Alessio Aprile. The equivalent experiment is TA23 at PLEXdb.]
Project description:To provide a global study of transcriptome changes under drought stress, the gene expression levels of a durum wheat genotype (Triticum durum Desf. cultivar Creso) and two bread wheat genotypes (Triticum aestivum L. cultivar Chinese Spring -CS- and its deletion line CS_5AL-10) were investigated. The 5A chromosome deletion line (5AL-10) lacks the distal part (43%) of the long arm of chromosome 5A. Each genotype was subjected to two different levels of water stress at the grain filling stage. After anthesis, three different levels of soil water content (SWC) were induced as described below: control (CTRL; SWC=28%), moderate stress (MS; SWC=18%), and severe stress (SS; SWC=12.5%). For each sample, three biological replicates were performed, for a total of 27 hybridizations. ****[PLEXdb(http://www.plexdb.org) has submitted this series at GEO on behalf of the original contributor, Alessio Aprile. The equivalent experiment is TA23 at PLEXdb.] genotype: Creso - stress condition: Control(3-replications); genotype: Creso - stress condition: Mild stress(3-replications); genotype: Creso - stress condition: Severe stress(3-replications); genotype: CS - stress condition: Control(3-replications); genotype: CS - stress condition: Mild stress(3-replications); genotype: CS - stress condition: Severe stress(3-replications); genotype: CS-5AL - stress condition: Control(3-replications); genotype: CS-5AL - stress condition: Mild stress(3-replications); genotype: CS-5AL - stress condition: Severe stress(3-replications)
Project description:Grain development is a key life cycle stage of many plants. The development of seeds is the basis of agriculture and the primary source of calories consumed by humans. Here, we employ laser micro dissection (LMD) combined with shotgun proteomics to generate a cell-type proteome atlas of developing wheat endosperm at the early and late grain filling stages. We identified 1803 proteins from four different cell layers (aleurone (AL), sub-aleurone (SA), starchy endosperm (SE), and endosperm transfer cells (ETCs)) of developing endosperm at 15 Days after anthesis (DAA) and 26 DAA. Sixty-seven differentially expressed proteins in the aleurone, 31 in the sub-aleurone, 27 in the starchy endosperm, and 50 in the endosperm transfer cells were detected between these two-time points. The results revealed highly distinguishable proteome dynamics in the different cell layers of endosperm over the time course. We observed high general metabolic activity of the grain with regard to carbohydrate metabolism, defence against oxidative stress, and signalling in the different cell layers during the grain filling process. Cell-specific identification of SUT and GLUT transporters suggest a grain filling model via nucellar projections and endosperm transfer cells (ETCs) initiating starch biosynthesis in the starchy endosperm (SE). The identification and regulation dynamics of proteins in the different cell layers demonstrate a functional switch of the proteome from the early to the late grain filling stage. Based on these data, we proposed a model for sugar loading and starch biosynthesis in wheat developing endosperm, including an abundance switch of cell-type-specific key proteins.
Project description:Cadmium (Cd) is one of the environmental pollutants contaminated in our food. Several previous reports showed that rice polishing cannot be efficient to reduce Cd content in white rice, implying the characteristic Cd distribution in rice grain. However, Cd distribution has not been fully elucidated so far. Herein, 109Cd radiotracer experiment was performed using the rice seedlings at various time points after flowering to obtain autoradiographs of the brown rice to visually understand the Cd transport and distribution during the grain-filling process. It was shown that 109Cd accumulated in the outermost area of the brown rice, and also in the middle part of the starchy endosperm, resulting in the appearance of the double circle distribution pattern, which was not observed in the autoradiographs of 65Zn. The inner circle of 109Cd located around the center of the endosperm was developed particularly at around 8 and 10 days after flowering. After this period, 109Cd started to deposit at the outer part of the endosperm, which was also found in the autoradiograph of 14C-sucrose. Considering the physiology of grain development, the contribution of water transport and protein synthesis in the endosperm on the characteristic Cd distribution pattern was hypothesized.
Project description:Thousand grain weight is one of the components determining wheat grain yield. It represents the average value of individual grain weights which depends on position within the ear and on positon within the spikelet. Our objective was to quantify the influences of individual floret anthesis date, of carpel weight at anthesis and of rate and duration of grain filling, on variation in individual final grain weight. Two bread wheat cultivars were grown in a greenhouse and their ears were sampled from anthesis through to harvest. Each ear was divided into three parts-basal, central and apical-where the two proximal grains were dissected from each of two spikelets. We analysed (i) the flowering time shift within the ear and within the spikelet; and (ii) the growth kinetics during grain filling in relation to position along the ear. For both cultivars, florets located in the central part of the ear were the first to reach anthesis followed by those in the apical part and then the basal part. Within a spikelet, the floret located nearest the rachis flowered first followed by the more distal ones. We found no significant systematic effect of flowering time-shift on final grain weight. Nevertheless, grains in the central part were heavier than the basal ones (9.75% smaller) and than the apical ones (18.25% smaller). These differences were explained mainly by differences in mean grain filling rates. Analysis of growth kinetics enabled an improved explanation of the variability of individual grain weight along the ear.
Project description:Individual grain weight is a major yield component in wheat. To provide a comprehensive understanding of grain weight determination, the carpel size at anthesis, grain dry matter accumulation, grain water uptake and loss, grain morphological expansion, and final grain weight at different positions within spikelets were investigated in a recombinant inbred line mapping population of bread wheat (Triticum aestivum L.)×spelt (Triticum spelta L.). Carpel size, grain dry matter and water accumulation, and grain dimensions interacted strongly with each other. Furthermore, larger carpels, a faster grain filling rate, earlier and longer grain filling, more grain water, faster grain water absorption and loss rates, and larger grain dimensions were associated with higher grain weight. Frequent quantitative trait locus (QTL) coincidences between these traits were observed, particularly those on chromosomes 2A, 3B, 4A, 5A, 5DL, and 7B, each of which harboured 16-49 QTLs associated with >12 traits. Analysis of the allelic effects of coincident QTLs confirmed their physiological relationships, indicating that the complex but orderly grain filling processes result mainly from pleiotropy or the tight linkages of functionally related genes. After grain filling, distal grains within spikelets were smaller than basal grains, primarily due to later grain filling and a slower initial grain filling rate, followed by synchronous maturation among different grains. Distal grain weight was improved by increased assimilate availability from anthesis. These findings provide deeper insight into grain weight determination in wheat, and the high level of QTL coincidences allows simultaneous improvement of multiple grain filling traits in breeding.
Project description:BackgroundConcentrations of cadmium (Cd) in the grain of many durum wheats (Triticum turgidum subsp. durum) grown in North American prairie soils often exceed international trade standards. Genotypic differences in root-to-shoot translocation of Cd are a major determinant of intraspecific variation in the accumulation of Cd in grain. We tested the extent to which changes in whole-plant Cd accumulation and the distribution of Cd between tissues influences Cd accumulation in grain by measuring Cd accumulation throughout the grain filling period in two near-isogenic lines (NILs) of durum wheat that differ in grain Cd accumulation.ResultsRoots absorbed Cd and transported it to the shoots throughout the grain filling period, but the low- and high-Cd NILs did not differ in whole-plant Cd uptake. Although the majority of Cd accumulation was retained in the roots, the low- and high-Cd NILs differed substantively in root-to-shoot translocation of Cd. At grain maturity, accumulation of Cd in the shoots was 13% (low-Cd NIL) or 37% (high-Cd NIL) of whole-plant Cd accumulation. Accumulation of Cd in all shoot tissue, including grain, was at least 2-fold greater in the high-Cd NIL at all harvests. There was no net remobilization of shoot Cd pools during grain filling. The timing of Cd accumulation in grain was positively correlated with grain biomass accumulation, and the rate of grain filling peaked between 14 and 28 days post-anthesis, when both NILs accumulated 60% of total grain biomass and 61-66% of total grain Cd content.ConclusionsThese results show that genotypic variation in root-to-shoot translocation of Cd controls accumulation of Cd in durum wheat grain. Continued uptake of Cd by roots and the absence of net remobilization of Cd from leaves during grain filling support a direct pathway of Cd transport from roots to grain via xylem-to-phloem transfer in the stem.
Project description:Wheat (T. aestivum L. Chinese Spring) plants were cultured in 25-cm buckets at a density of 16 plants per bucket in a greenhouse at a temperature of 15–30 °C. Plants were watered once a week, and artificial light was applied when there was fewer than 12 h of natural daylight. The flowering date of each spike was recorded when the first flower appeared on the spike. Comparable wheat plants were selected depending on the flowering time and growth status and were transferred into growth chambers 12 DAF for a three-day adaptation period to the growth chamber environment (24/17 °C, 14/10 h day/night cycle). Wheat plants were illuminated with a photosynthetic photon flux density of 360 µmol m˗2 s˗1 at canopy height, and relative humidity ranged from 40% to 70%. Half of the wheat plants (about 50 plants) were transferred to heated conditions (37/17 °C, 14/10 h day/night cycle, 40% to 70% humidity), while the others were maintained under the standard conditions described above as a control. After three day/night cycles, the heated samples were collected after the plants had been exposed to heat for 4 h, and the control samples from the unheated chambers were collected at the same time for and proteomic analyses. A minimum of 20 spikes were collected from each condition, immediately immersed in liquid nitrogen and stored at ˗80 °C until further analysis.
Project description:Investigation of genome wide expression level changes during 11 stages of wheat grain development in normal growth conditions (19°C).
Project description:grain-filling period wheat grains of the near-isogenic lines 16-723 and 16-1010, which have large differences in quality, to perform proteome analysis