Progress 05/01/24 to 04/30/25
Outputs
Target Audience:The findings from this research project were shared with plant scientists and students during the Association of 1890 Land Grant Research Directors Symposium in Nashville, Tennessee, from April 6 to 9, 2024, and at the Plant and Animal Genome Conference in San Diego from January 10 to 15, 2025. Changes/Problems:A sorghum recombinant inbred line population - Tx642/Tx7000 - with 125 entries was planted at Texas A&M in College Station, Texas with two replications in early April 2024. Weather conditions in this location at that time and during the growing season were excessively wet, leading to poor emergence due to seedling disease. This was exacerbated by such excessive weed pressure (due to the rain) that a decision to terminate the test was made in early June. This RIL population will be planted again in 2025 in a second attempt togenerate phenotypic data for QTL analyses. What opportunities for training and professional development has the project provided?This project provided training opportunities for a recent Ph.D. graduate who joined as a postdoc, partially funded by the grant. Additionally, the project offered training to undergraduate student at Prairie View A&M University. The posted presented research results at the 1890 Association of Research Directors (ARD) conference in Nashville, Tennessee, from April 6 to April 9, 2023. How have the results been disseminated to communities of interest?The findings from this study were shared through publication, poster presentations, and seminars at national conferences. What do you plan to do during the next reporting period to accomplish the goals?Research and manuscript preparation are ongoing. New results will be analyzed, and manuscript preparation will be completed during the next reporting period.
Impacts
What was accomplished under these goals?
The expression of known flowering, plant hormone, and sugar-related genes was investigated in detail in sorghum buds subjected to shade and defoliation treatments. The study revealed that while shade signals and defoliation induce bud dormancy by reducing the sugar supply necessary for bud growth, shade signals, and not defoliation, activate flowering-inhibiting molecular mechanisms possibly to counteract the early flowering signals generated by shade and ensuring that dormant buds do not respond to flowering cues before they develop into branches. The analysis of RNA-seq data from 36 leaf samples from sorghum phytochrome B mutants and wild-type plants exposed to shade signals were sequenced, yielding an average of 65 million paired-end RNA reads per sample. The RNA-seq data analysis has been completed, and a manuscript is currently being prepared. In addition, RNA-seq data were generated from 27 sorghum bud samples from control and 2 treatments (C: control; D: defoliation; F: far-red light) at 3 time points (1h, 24h, 48h post-treatment), with 3 biological replicates per condition. Approximately 11.07 to 17.79 million reads were produced per library (sample). The data analysis has been completed a mamnuscript is currently being prepared for publication.
Publications
- Type:
Peer Reviewed Journal Articles
Status:
Published
Year Published:
2024
Citation:
Kebrom TH (2024) Shade signals activate distinct molecular mechanisms that induce dormancy and inhibit flowering in vegetative axillary buds of sorghum. Plant Direct, 8(8), e626. https://doi.org/10.1002/pld3.626
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Progress 05/01/23 to 04/30/24
Outputs
Target Audience:
Nothing Reported
Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?The project provided training to a female undergraduate student at Prairie View A&M University on research methods, using seed germination bioassay of sorghum and maize as models. The student was trained on data collection, data analysis , and communicating research results. The student presented her work in a poster to the 1890 land-grant universities scientific community at the 1890 Association of Research Directors (ARD) conference in Nashville, Tennessee, from April 6 to April 9 and received an award. How have the results been disseminated to communities of interest?
Nothing Reported
What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Objective 1. The expression of dormancy flowering, plant hormone metabolism, and sugar-responsive marker genes were analyzed using qPCR in dormancy induced by shade signals and defoliation in sorghum axillary buds. The results revealed that shade signals activate distinct molecular mechanisms that induce dormancy and inhibit flowering in axillary buds. A manuscript reporting the results of the study has been prepared and is currently under review for publication. RNA-seq data from sorghum phytochrome B mutant and wild type grown with shade signals were generated. The data was generated from three positions, the basal, middle, and apical sections, of a single leaf, each from four leaf/plant samples from the three genotypes. Thus, a total of 36 samples were sequenced, and an average of 65 million paired-end RNA reads were generated from each sample. The RNA-seq data analysis has been completed, and a manuscript is being prepared to disseminate the results to the scientific community. Objective 3. To conduct QTL mapping for tillering and related traits, diverse sorghum parental genotypes were grown in the field during the 2023 growing season at the Texas A&M University field experiment station in College Station, Texas. The number of plants and panicles per plant were counted at maturity. Based on the results of the study and our previous knowledge of the extent of tillering in some of the genotypes, six recombinant inbred lines developed from the parental genotypes are being grown during the current 2024 growing season at the Texas A&M University field experiment station in College Station, Texas, to map QTLs for tillering.
Publications
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Progress 05/01/22 to 04/30/23
Outputs
Target Audience:
Nothing Reported
Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?
Nothing Reported
How have the results been disseminated to communities of interest?
Nothing Reported
What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
The major grain crops, including maize, wheat, and sorghum, provide most of the global caloric needs. The demand for grain crops will increase in the coming decades to feed the growing world population. However, the relative yield gains of these crops have declined in recent decades, and growing these crops is becoming less profitable for US farmers. Our long-term goal is to increase the yield of these crops by optimizing shoot branching, which is a major trait of crops that significantly influences resource use efficiency and yield. Shoot branches develop from axillary buds. The objective of the ongoing project is to identify candidate genes that control axillary bud dormancy and growth using sorghum and maize as models. The genes will be identified using two approaches, molecular and genetic. The genes will enable to improving shoot branching and increasing crop yield, ensure sustainable and profitable crop production in the US, and satisfy the global demand for food. The goals accomplished for Objective 1 using molecular approaches includeexpression analysis of dormancy, plant hormone, and sugars-related genes associated with axillary bud dormancy or growth in sorghum in response to shade and defoliation. The gene expression data helps to refine the experimental design and the timing of bud sampling from sorghum plants for RNA sequencing (RNA-seq). In addition, the candidate gene expression analysis identified common and distinct molecular mechanisms inducing bud dormancy by shade and defoliation.RNA-seq analysis of leaves of sorghum was also completed. This data will be used as a reference to identify bud-specific genes, that is, genes that are expressed in the buds but not in the leaves. Also, for Objective 3 involving genetic approaches, about 25 sorghum parental lines were planted in the field. The lines will be scored for shoot branch number and relate plant traits that affect shoot branching, including plant height and flowering time. The data from this experiment will be used to select Recombinant Inbred Lines (RILs) developed from these parental lines that vary in shoot branching for mapping and identifying genes that control shoot branching.
Publications
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