Project description:The goal of this study was to perform RNA-seq expression analysis on Solanum lycopersicum cv. M82 X S. pennellii introgression lines, deriving expression Quantitative Trait Loci which were analyzed together with pre-existing genomic and phenotypic data to define genes and regulatory pathways controlling tomato root development and observed natural variation. We completed the RNAseq expression profiling analysis and developed a tool to display this information graphically in collaboration with Nicholas Provart at the University of Toronto: http://bar.utoronto.ca/efp_tomato/cgi-bin/efpWeb.cgi?dataSource=ILs_Root_Tip_Brady_Lab To identify candidate genes and pathways we focussed on one root growth trait, root growth angle, and identified two statistically significant genomic regions within tomato root growth angle QTL containing two candidate genes that likely control the gravitropic setpoint angle (CDC73 and PAP27), both of which are conserved between Arabidopsis and tomato, and which we tested using transgenic lines of the Arabidopsis orthologs. A possible regulatory role for suberin in root growth angle control was also identified.
Project description:High throughput sequencing was used to investigate the production of small RNAs from cultivated tomato cultivar M82 and its wild relative Solanum pennellii. In order to understand the pattern of inheritance of the samll RNAs, interspecific hybrids (F1 and F2) along with series of introgressed lines comprising precise short genomic regions from S. pennellii in M82 background were used.
Project description:This experiment investigates a time series of seed development in Medicago truncatula. Time points 14, 16, 20, 24, and 36 days post pollination are hybridized against a 12 days post pollination reference stage.
Project description:High throughput sequencing was used to investigate the production of small RNAs from cultivated tomato cultivar M82 and its wild relative Solanum pennellii. In order to understand the pattern of inheritance of the samll RNAs, interspecific hybrids (F1 and F2) along with series of introgressed lines comprising precise short genomic regions from S. pennellii in M82 background were used. Examination of small RNA production in several tomato lines.
Project description:Tomato plants are sensitive to drought stress throughout their growth cycle. To be considered drought-tolerant, a cultivar should display tolerance at all developmental stages. This study aimed to evaluate whether Solanum pennellii introgression lines (ILs) previously selected as drought-tolerant during germination/seedling growth maintained this tolerance in the vegetative/reproductive stage. We then investigated these ILs to uncover candidate genes. The plants were subjected to two different environmental conditions: well-watered and drought-stressed (water withheld for ≤ 20 d after flowering). Phenotyping for morphological, physiological, fruit quality, and yield-related traits was performed, and the data was analyzed using a mixed-model approach. Using a multi-trait index that relies on factor analysis and genotype-ideotype distance (FAI-BLUP index), the genotypes were ordered based on how far they were from the drought-tolerant ideotype. Afterward, the tomato IL population map furnished by the SOL Genomics Network was utilized to identify introgressed segments of significance for the identification of candidate genes. Significant genotypic differences were found in the yield, water content, mean weight, length, and width of the fruit, the percentage of fruits displaying blossom-end rot, and titratable acidity. The drought-tolerance ideotype was built considering the maximum values for the fruit water content, number of fruits, mean fruit weight, and yield, minimum values for blossom-end rot, and mean values for titratable acidity. IL 1-4-18, IL 7-4-1, IL 7-1, IL 7-5-5, and IL 1-2 were ranked above M-82 and therefore considered drought-tolerant during the vegetative/reproductive stage. IL 1-4-18 and IL1-2 sustained drought tolerance displayed during germination/seedling growth into the vegetative/reproductive stage. The following candidate genes associated with drought tolerance were identified: AHG2, At1g55840, PRXIIF, SAP5, REF4-RELATED 1, PRXQ, CFS1, LCD, CCD1, and SCS. Because they are already associated with genetic markers, they can be transferred to elite tomato cultivars through marker-assisted technology after validation.