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:Chilling stress is a major factor limiting the yield and quality of vegetable soybean (Glycine max L.) on a global scale. Systematic identification and function analysis of miRNA under chilling stress could be helpful to clarify the molecular mechanism of chilling resistance. In the present study, two independent small RNA libraries from leaves of vegetable soybean were constructed, and sequenced with the high-throughput Illumina Solexa system. A total of 434 known miRNAs and three novel miRNAs were identified. Moreover, the expression patterns of these miRNAs have been verified by qRT-PCR analysis. Furthermore, we identified their gene targets by high-throughput degradome sequencing and validated using 5'-RACE. A total of 898 transcripts were targeted by 54 miRNA families attributed to five categories. More importantly, we identified 55 miRNAs that differentially expressed between chilling stress and the control. The targets of these miRNAs were enriched in oxidation-reduction, signal transduction, and metabolic process functional categories. The qRT-PCR confirmed that there was a negative relationship among the miRNAs and their targets under chilling stress. Our work provides comprehensive molecular evidence for the possible involvement of miRNAs in the process of chilling-stress responses in vegetable soybean.
Project description:Alkali stress is one of the most severe abiotic stresses affecting agricultural production worldwide. To understand the phosphorylation events in soybean in response to alkali stress, we performed the TMT labeling-based quantitative phosphoproteomic analyses on soybean leaf and root tissues under 50 mM NaHCO3 treatment.
Project description:Tropospheric ozone (O3) is a secondary air pollutant and anthropogenic greenhouse gas. Concentrations of tropospheric O3 have more than doubled since the Industrial Revolution, and are high enough to damage plant productivity. Soybean (Glycine max L. Merr.) is the worldâs most important legume crop and is sensitive to O3. Current ground-level O3 are estimated to reduce global soybean yields by 6% to 16%. In order to understand transcriptional mechanisms of yield loss in soybean, we examined the transcriptome of soybean flower and pod tissues exposed to elevated O3 using RNA-Sequencing.
Project description:Soybean (Glycine max) seeds are an important source of seed storage compounds, including protein, oil, and sugar used for food, feed, chemical, and biofuel production. We assessed detailed temporal transcriptional and metabolic changes in developing soybean embryos to gain a systems biology view of developmental and metabolic changes and to identify potential targets for metabolic engineering. Two major developmental and metabolic transitions were captured enabling identification of potential metabolic engineering targets specific to seed filling and to desiccation. The first transition involved a switch between different types of metabolism in dividing and elongating cells. The second transition involved the onset of maturation and desiccation tolerance during seed filling and a switch from photoheterotrophic to heterotrophic metabolism. Clustering analyses of metabolite and transcript data revealed clusters of functionally related metabolites and transcripts active in these different developmental and metabolic programs. The gene clusters provide a resource to generate predictions about the associations and interactions of unknown regulators with their targets based on “guilt-by-association” relationships. The inferred regulators also represent potential targets for future metabolic engineering of relevant pathways and steps in central carbon and nitrogen metabolism in soybean embryos and drought and desiccation tolerance in plants. SUBMITTER_CITATION: Biology 2013, 2(4), 1311-1337; doi:10.3390/biology2041311 Changes in RNA Splicing in Developing Soybean (Glycine max) Embryos Delasa Aghamirzaie, Mahdi Nabiyouni, Yihui Fang, Curtis Klumas, Lenwood S. Heath, Ruth Grene and Eva Collakova SUBMITTER_CITATION: Metabolites 2013, 3(2), 347-372; doi:10.3390/metabo3020347 Metabolic and Transcriptional Reprogramming in Developing Soybean (Glycine max) Embryos Eva Collakova, Delasa Aghamirzaie, Yihui Fang, Curtis Klumas, Farzaneh Tabataba, Akshay Kakumanu, Elijah Myers, Lenwood S. Heath and Ruth Grene Total mRNA profiles of 10 time course samples of Soybean developing embryos with three replicates per sample were generated by deep sequencing, using Illumina HiSeq 2000
Project description:Background The homeodomain leucine zipper (HD-Zip) transcription factor family is one of the largest plant specific superfamilies, and includes genes with roles in modulation of plant growth and response to environmental stresses. Many HD-Zip genes are characterized in Arabidopsis (Arabidopsis thaliana), and members of the family are being investigated for abiotic stress responses in rice (Oryza sativa), maize (Zea mays), poplar (Populus trichocarpa) and cucumber (Cucmis sativus). Findings in these species suggest HD-Zip genes as high priority candidates for crop improvement. Results In this study we have identified members of the HD-Zip gene family in soybean cv. 'Williams 82', and characterized their expression under dehydration and salt stress. Homology searches with BLASTP and Hidden Markov Model guided sequence alignments identified 101 HD-Zip genes in the soybean genome. Phylogeny reconstruction coupled with domain and gene structure analyses using soybean, Arabidopsis, rice, grape (Vitis vinifera), and Medicago truncatula homologues enabled placement of these sequences into four previously described subfamilies. Of the 101 HD-Zip genes identified in soybean, 88 exist as whole-genome duplication-derived gene pairs, indicating high retention of these genes following polyploidy in Glycine ~10 Mya. The HD-Zip genes exhibit ubiquitous expression patterns across 24 conditions that include 17 tissues of soybean. An RNA-Seq experiment performed to study differential gene expression at 0, 1, 6 and 12 hr soybean roots under dehydration and salt stress identified 20 differentially expressed (DE) genes. Several of these DE genes are orthologs of genes previously reported to play a role under abiotic stress, implying conservation of HD-Zip gene functions across species. Screening of HD-Zip promoters identified transcription factor binding sites that are overrepresented in the DE genes under both dehydration and salt stress, providing further support for the role of HD-Zip genes in abiotic stress responses. Conclusions We provide a thorough description of soybean HD-Zip genes, and identify potential candidates with probable roles in dehydration and salt stress. Expression profiles generated for all soybean genes, under dehydration and salt stress, at four time points, will serve as an important resource for the soybean research community, and will aid in understanding plant responses to abiotic stress.