Project description:This SuperSeries is composed of the following subset Series: GSE29663: Expression profiling of soybean genes in response to drought (vegetative stage) GSE40604: Expression profiling of soybean genes in response to drought (reproductive stage) Refer to individual Series
Project description:Drought-responsive genes in soybean leaves were successfully identified using Affymetrix Soybean Gene 1.0 ST arrays on leaves samples of reproductive-stage soybean plants. R1 soybean plants planted in pots were imposed drought by withholding water for 5 days until the soil moisture content dropped to 5%, and 3rd trifoliates (now at the R2 stage) were collected for expression profiling.
Project description:Plants remember what they have experienced and are thereby able to confront repeated stresses more promptly and strongly. A subset of genes showed increased transcript levels under drought stress conditions, followed by a return to basal levels during recovery (watered) states, and then displayed elevated levels again under subsequent drought conditions. To screen for a set of drought stress memory genes in soybean (Glycine max L. cv. Daepoong), we designed a 180K DNA chip comprising 60-bp probes synthesized in situ to examine 55,588 loci. Through microarray analysis using the DNA chip, we identified 2,165 and 2,385 genes with more than 4-fold increases or decreases in transcript levels, respectively, under initial (first) drought stress conditions, when compared with the non-treated control. The transcript levels of the genes returned to basal levels during recovery (watered) states, then 677 and 987 genes displayed more than 16-fold elevated or reduced levels, respectively, under subsequent (second) drought conditions, when compared to the non-treated control. Gene Ontology analysis classified the drought stress memory genes into several functional categories, including those involved in trehalose biosynthesis and drought tolerance responses. We selected a number of drought stress memory genes encoding various transcription factors, protein phosphatase 2Cs, and late embryogenesis abundant proteins, and confirmed the microarray data by quantitative reverse-transcription real-time PCR. Upon repeated watering and subsequent (third) drought treatment, the elevated levels of the drought stress memory gene transcripts were propagated into newly developed second leaves, although at reduced levels when compared to the second drought treatment on the first leaves.
Project description:Drought-responsive genes in soybean leaves were successfully identified using Affymetrix Soybean Gene 1.0 ST arrays on leaves samples of reproductive-stage soybean plants. R1 soybean plants planted in pots were imposed drought by withholding water for 5 days until the soil moisture content dropped to 5%, and 3rd trifoliates (now at the R2 stage) were collected for expression profiling. Soybean plants were grown in pots. When the plants reached the R1 stage (started flowering), drought treatment was imposed by withholding water. The soil moisture content was monitored during the process until the 5th day of water withholding, when soil moisture content reached 5%. The 3rd trifoliate (counting from shoots), now at the R2 stage, was collected for total RNA extraction, while other 3rd trifoliates of similar chlorophyl index were collected for leaves water content determination to identify the severity of the stress. Total RNA from 3rd trifoliates were used for expression profiling using Affymetrix Soybean Gene 1.0 ST arrays. Four biological repeats per treatment were performed, three biological repeats were chosen for expression profiling.
Project description:Background: Pollen, the male partner in the reproduction of flowering plants, comprises either two or three cells at maturity. The current knowledge of the pollen transcriptome is limited to the model plant Arabidopsis thaliana, which has tri-cellular pollen grains at maturity. Comparative studies on pollen of other genera, particularly crop plants, are needed to understand the pollen gene networks that are subject to functional and evolutionary conservation. In this study, we used the Affymetrix Soybean GeneChip® to perform transcriptional profiling on mature bi-cellular soybean pollen. Results: Compared to the sporophyte transcriptome, the soybean pollen transcriptome revealed a restricted and unique repertoire of genes, with a significantly greater proportion of specifically expressed genes than is found in the sporophyte tissue. Comparative analysis shows that, among the 37,500 soybean unique transcripts addressed in this study, 10,299 genes (27.46%) are expressed in pollen. Of the pollen-expressed genes, about 9,489 (92.13%) are also expressed in sporophytic tissues, and 810 (7.87%) are selectively expressed in pollen. Overall, the soybean pollen transcriptome shows an enrichment of transcription factors (mostly zinc finger family proteins), cell cycle-related transcripts, signal recognition receptors, ethylene responsive factors, chromatin remodeling factors, and members of the ubiquitin proteasome proteolytic pathway. Moreover, we identify several new pollen-specific candidate genes that might play a significant role in pollen biology. Conclusion: This is the first report of a soybean pollen transcriptional profile. These data extend our current knowledge regarding regulatory pathways that govern the gene regulation and development of pollen. We also demonstrate that pollen is a rich store of regulatory proteins that are essential and sufficient for de novo gene expression. A comparison between transcription factors up-regulated in soybean and those upregulated in Arabidopsis revealed some divergence in the numbers and kinds of regulatory proteins expressed in both species.