ABSTRACT: Comparing a Mixed Model Approach to Traditional Stability Estimators for Mapping Genotype by Environment Interactions and Yield Stability in Soybean
Project description:Soybean aphids are phloem-feeding pests that can cause significant yield losses in soybean plants. Soybean aphids thrive on susceptible soybean lines but not on resistant lines. We used microarrays to characterize the soybean plant's transcriptional defense against aphids in two related cultivars, a susceptible line and a resistant line with the Rag1 aphid-resistance gene. We measured trancript levels in leaves after one and seven days of aphid infestation.
Project description:Soybean is a rich source of protein and oil and a primary feedstock for biodiesel production. Previous research on soybean indicated that protein, oil and yield are controlled quantitatively in soybean seeds. However, genetic mechanisms controlling seed composition and yield in soybean remain unknown. We used Affymetrix Soybean GeneChips® to identify genes that are differentially expressed between developing seeds of the Minsoy and Archer soybean varieties, which differ in seed weight, yield, protein content and oil content. Some of the differentially expressed genes identified in this study may play important roles in controlling these traits.
Project description:Soybean aphids are phloem-feeding pests that can cause significant yield losses in soybean plants. Soybean aphids thrive on susceptible soybean lines but not on resistant lines. Aphids do not normally kill their host and colonize plants for long periods of time, up to several months in soybean. However, our knowledge of plant responses to long-term aphid colonization is very limited. We used microarrays to characterize the soybean plant's transcriptional response against aphids in two related cultivars, a susceptible line and a resistant line with the Rag1 aphid-resistance gene. We measured transcript levels in leaves after 21 days of aphid infestation.
Project description:The soybean aphid, a plant sap sucking insect, is an important soybean pest in the USA causing significant yield losses. The Rag2 gene of soybean provides resistance to soybean aphid biotypes I and II. Transcriptomic analyses were performed on near isogenic lines (NILs) with the Rag2 allele for aphid resistance or rag2 for susceptibility at the Rag2 locus. Soybeans were infested with soybean aphids and leaves were collected at 0, 4, 8, 24, and 48 hours after infestation. RNA were extracted and a high throughput RNA-seq approach was used to examine mRNA expression in Rag2 and rag2 soybean leaves. The expression of ~43,000 genes was detected in both the Rag2 and rag2 leaves. Statistical analysis identified 2361 genes significantly regulated between the resistant and susceptible lines at different times after aphid infestation. Genes found up-regulated in the Rag2 line were annotated as involved in the cell wall, secondary and hormone metabolism, as well as in stress, signaling and transcriptional responses. Genes found up-regulated in the rag2 line were annotated as involved in photosynthesis and carbon metabolism. Interestingly, mRNAs of 2 genes (unknown and mitochondrial protease) located within the Rag2 locus were expressed significantly higher in the resistant genotype. The expression of the putative NBS-LRR resistant gene present in the Rag2 locus was not different between the two soybean lines. However, another NBL-LRR gene located just at the border of the Rag2 locus was and, therefore, may be involved in the differential resistance to aphid infestation exhibited by the two NIL genotypes analyzed.
Project description:Purpose: Soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae) and soybean cyst nematode, Heterodera glycines Ichinohe, (SCN) are the two most economically important pests of soybean, Glycine max (L.) Merr., in the Midwest. Although the soybean aphid is an aboveground pest and SCN is a belowground pest there is evidence that concomitant infestations result in improved SCN reproduction. This study is aimed to characterize the three-way interactions among soybean, soybean aphid and SCN using demographic and genetic datasets. Results: More than 1.1 billion reads (61.4 GB) of transcriptomic data were yielded from 47 samples derived from the experiment using whole roots of G. max. The phred quality scores per base for all the samples were higher than 30. The GC content ranged from 43 to 45% and followed the normal distribution. After trimming, more than 99% of the reads were retained as the clean and good quality reads. Upon mapping these reads, we obtained high mapping rate ranging from 73.8% to 94.3%. Among the mapped reads, 67.1% to 87.6% reads were uniquely mapped. Conclusions: The comprehensive understanding of these transcriptome data would help in understanding the molecular interactions among soybean, A. glycines, and H. glycines. The use of multifaceted bioinformatics approaches could facilitate finding candidate genes and their function that might play a crucial role in various pathways for host resistance against both soybean aphids and SCN. For differential gene expression analysis, EdgeR, limma, and DEseq2 could be used. Apart from standalone tools like iDEP, Galaxy (https://usegalaxy.org), CyVerse (http://www.cyverse.org), and MeV (http://mev.tm4.org) could also be used for both analysis and visualization of RNA- seq data.
Project description:Soybean is a rich source of protein and oil and a primary feedstock for biodiesel production. Previous research on soybean indicated that protein, oil and yield are controlled quantitatively in soybean seeds. However, genetic mechanisms controlling seed composition and yield in soybean remain unknown. We used Affymetrix Soybean GeneChips® to identify genes that are differentially expressed between developing seeds of the Minsoy and Archer soybean varieties, which differ in seed weight, yield, protein content and oil content. Some of the differentially expressed genes identified in this study may play important roles in controlling these traits. The soybean plants of two soybean varieties Minsoy and Archer and two recombinant inbred lines from the cross that are similar in maturity but differ in yield were grown in St Paul, Minnesota during the summers of 2007 and 2008. In 2007, each line was planted as a single row. In 2008, a randomized complete block (RCB) design was used and each line had 3 replicates planted 1-2 weeks apart. Within each replicate, two rows per line were planted. Seeds were harvested at three developmental stages, namely, seed length = 2 mm, 3.5 mm, and 5-6 mm, which correspond approximately to soybean reproductive stages R4, R5 and early R6, respectively. In 2007 three independent samples were collected for each line and developmental stage. In 2008, two seed samples (one from each row) were collected for each line at each stage within each replicate. The pairs of seed samples were then pooled. Thus, three sets of independent tissue samples were collected for RNA extraction and hybridization on Affymetrix microarrys.
Project description:Soybean aphids are phloem-feeding pests that can cause significant yield losses in soybean plants. Soybean aphids thrive on susceptible soybean lines but not on resistant lines. We used microarrays to characterize the soybean plant's transcriptional defense against aphids in two related cultivars, a susceptible line and a resistant line with the Rag1 aphid-resistance gene. We measured trancript levels in leaves after one and seven days of aphid infestation. This was a full-factorial experiment with three factors: soybean variety (susceptible SD01-76R,resistant LD05-16060), aphid treatment (control, aphids), and infestation duration (1 day, 7 days). There were three replicates per treatment, for a total of 24 samples. The experiment was carried out in a growth chamber. At the V3 growth stage, thirty aphids were added to the third trifoliate leaves of the aphid-treated plants. Each plant had a net to prevent aphid movement among different plants. The aphids were removed prior to sampling.
Project description:CGH was used to compare structural variation among four soybean cultivars (Archer, Minsoy, Noir1 and Williams 82). Three different soybean cultivars (Archer, Minsoy and Noir1) were hybridized against the common reference genotype Williams 82. The soybean tiling array consists of 700k probes, spaced at approximately 1.1 kb intervals.
Project description:Soybean plants were subjected to water deficit, heat stress, and combination of water deficit and heat stress along with control condition and pods were analysed for temperature, water potential, transpiration, yield and differential gene expression compared to control.