Project description:To better undersand the effects of drought stress on wheat developing seeds, the transcription profile of early developing wheat seeds under control and drought stress conditions were comparatively analyzed by using the Affymetrix wheat geneChip. Drought stress is a major yield-limiting factor for wheat. Wheat yields are particularly sensitive to drought stress during reproductive development. Early seed development stage is an important determinant of seed size, one of the yield components. We specifically examined the impact of drought stress imposed during postzygotic early seed development in wheat. We imposed a short-term drought stress on plants with day-old seeds and observed that even a short-duration drought stress significantly reduced the size of developing seeds as well as mature seeds. Drought stress delayed the developmental transition from syncytial to cellularized stage of endosperm. Coincident with reduced seed size and delayed endosperm development, a subset of genes associated with cytoskeleton organization was misregulated in developing seeds under drought-stressed. Several genes linked to hormone pathways were also differentially regulated in response to drought stress in early seeds. Notably, drought stress strongly repressed the expression of wheat storage protein genes such as gliadins, glutenins and avenins as early as 3 days after pollination. Our results provide new insights on how some of the early seed developmental events are impacted by water stress, and the underlying molecular pathways that can possibly impact both grain size and quality in wheat. Winter wheat cultivar Redland, PI 502907 (Triticum aestivum L.) was used for this study. Seedlings were vernalized at 4°C for 6 weeks and then transplanted to a one gallon pot of soil-sand mixture (3:1, v/v) and grown in a growth chamber under the following conditions: relative humidity, 50–70%; 16-h light/8-h dark photoperiod; 21°C daytime temperature and 18°C nights. Plants were watered regularly twice daily at the rate of 100ml/ per pot. Because, wheat has an asynchronous fertilization pattern for ovlues in the inflorescence, each floret needs to be specifically marked for timing the fertilization and stress induction. After spikes developed, unfertilized ovules were monitored and observed for the fertilization process. Closed wheat spikes with anthers outside were marked as fertilized. Drought stress was imposed 24h after the fertilization (HAF). Drought stress treatment was initiated by discontinuing watering on the drought treatment plants while control plants were regularly watered twice daily. Stress treatment was applied at 48 HAF and relieved at 96 HAF. The microarray study focuses on 24 HAF to 72 HAF in control and drought stress conditions. We started to impose drought stress 24HAF.

Project description:Six months old seed grown under well-watered greenhouse conditions were used in the current study. The seedlings of the two wild emmer wheat genotypes were vernalized on a moist germination paper (Hofman Manufacturing, Inc, Jefferson, OR, USA) for three weeks in the dark at 4oC, followed by three days acclimation at 24oC. Seedlings were then transplanted into 5L pots containing a mixture of pure quartz sand and peat (4:1 v/v), supplemented with a slow release fertilizer (2 g/L, Osmocote® Standard 14-14-14, Scotts-Sierra Horticulture, Marysville, OH, USA) and by a weekly application of 100 ml/pot of 0.5X Murashigi and Skoog growth solution (Sigma Chemical Co., St Louis, MO, USA). Pots were placed in a screen-house under natural winter conditions (December to February; 5-18°C) in Haifa, Israel (Mt. Carmel; 35o01′ E, 32o45′ N; 480 m above sea level) for 10 weeks and irrigated daily by a drip irrigation system. Three weeks prior to application of terminal drought stress, the pots were transferred to a controlled environment greenhouse (22/18 oC; 12 h day/12 h night) in order to prevent rainfall during the drought experiment. Five pots per genotype served as biological replicates, plants of three pots of each genotype/treatment were used for transcriptome study whereas two additional pots were used for quantitative PCR analysis (altogether five biological replicated of were used for quantitative real time PCR). Three individual plants were grown in each pot, one plant was used for measurements of leaf relative water content (RWC) (Barrs and Weatherley 1968), whereas the other two plants were used for sampling of flag leaf tissue for RNA extraction. Terminal drought stress (D) was applied at inflorescence emergence stage (Zadoks 50-60), (Zadoks et al. 1974), after emergence of 1-2 spikes in all biological replicates of both genotypes. The time from transplanting to inflorescence emergence stage was not significantly different between genotypes (70 days in the S genotype and 72 days in the R genotype). Drought stress application initiated after irrigation with excess amount of water in order to assure that all pots start the experiment at the same soil water capacity. Drought stress was imposed by withholding water for eight days until stress symptoms (i.e. leaf rolling and wilting symptoms) were visible in plants of both genotypes. Stress symptoms were more visible in the S genotype, however, leaf relative water content (RWC), measured after eight days of drought stress was low but was not significantly different between the two genotypes (49.68%±1.48 in the R genotype and 53.34%±1.83 in the S genotype). The well-watered control (C) plants were irrigated daily by ample amount of water. Flag leaf tissues of drought-stressed plants and well-watered control plants were harvested, immediately frozen in liquid nitrogen, and stored at -80ºC for RNA extraction. ****[PLEXdb(http://www.plexdb.org) has submitted this series at GEO on behalf of the original contributor, Krugman Tamar. The equivalent experiment is TA33 at PLEXdb.]

Project description:Six months old seed grown under well-watered greenhouse conditions were used in the current study. The seedlings of the two wild emmer wheat genotypes were vernalized on a moist germination paper (Hofman Manufacturing, Inc, Jefferson, OR, USA) for three weeks in the dark at 4oC, followed by three days acclimation at 24oC. Seedlings were then transplanted into 5L pots containing a mixture of pure quartz sand and peat (4:1 v/v), supplemented with a slow release fertilizer (2 g/L, Osmocote® Standard 14-14-14, Scotts-Sierra Horticulture, Marysville, OH, USA) and by a weekly application of 100 ml/pot of 0.5X Murashigi and Skoog growth solution (Sigma Chemical Co., St Louis, MO, USA). Pots were placed in a screen-house under natural winter conditions (December to February; 5-18°C) in Haifa, Israel (Mt. Carmel; 35o01′ E, 32o45′ N; 480 m above sea level) for 10 weeks and irrigated daily by a drip irrigation system. Three weeks prior to application of terminal drought stress, the pots were transferred to a controlled environment greenhouse (22/18 oC; 12 h day/12 h night) in order to prevent rainfall during the drought experiment. Five pots per genotype served as biological replicates, plants of three pots of each genotype/treatment were used for transcriptome study whereas two additional pots were used for quantitative PCR analysis (altogether five biological replicated of were used for quantitative real time PCR). Three individual plants were grown in each pot, one plant was used for measurements of leaf relative water content (RWC) (Barrs and Weatherley 1968), whereas the other two plants were used for sampling of flag leaf tissue for RNA extraction. Terminal drought stress (D) was applied at inflorescence emergence stage (Zadoks 50-60), (Zadoks et al. 1974), after emergence of 1-2 spikes in all biological replicates of both genotypes. The time from transplanting to inflorescence emergence stage was not significantly different between genotypes (70 days in the S genotype and 72 days in the R genotype). Drought stress application initiated after irrigation with excess amount of water in order to assure that all pots start the experiment at the same soil water capacity. Drought stress was imposed by withholding water for eight days until stress symptoms (i.e. leaf rolling and wilting symptoms) were visible in plants of both genotypes. Stress symptoms were more visible in the S genotype, however, leaf relative water content (RWC), measured after eight days of drought stress was low but was not significantly different between the two genotypes (49.68%±1.48 in the R genotype and 53.34%±1.83 in the S genotype). The well-watered control (C) plants were irrigated daily by ample amount of water. Flag leaf tissues of drought-stressed plants and well-watered control plants were harvested, immediately frozen in liquid nitrogen, and stored at -80ºC for RNA extraction. ****[PLEXdb(http://www.plexdb.org) has submitted this series at GEO on behalf of the original contributor, Krugman Tamar. The equivalent experiment is TA33 at PLEXdb.] genotype: Drought resistant (R) Y12-3 - treated or untreated: Well-watered(3-replications); genotype: Drought resistant (R) Y12-3 - treated or untreated: terminal drought(3-replications); genotype: Drought susceptible (S) A24-39 - treated or untreated: Well-watered(3-replications); genotype: Drought susceptible (S) A24-39 - treated or untreated: terminal drought(3-replications)

Dataset Information

Transcriptomic profile of wheat seed development under progressive drought conditions

Dataset's files

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets