Progress 12/15/19 to 12/14/20
Outputs
Target Audience:Cucumber breeders and producers, as well as scientists studying stress tolerance. Changes/Problems:COVID-19 resulted in restricted access to university research facilities, delaying progress towards research goals. Graduate students and post-docs were not allowed in labs from march through august, and subsequently only with time restrictions to ensure only one person is in a lab facility or office at any given time. What opportunities for training and professional development has the project provided?Graduate student and post doc gained experience with RNA-seq in organelles and nucleus. Graduate student presented research as the Plant and Animal Genome meeting in January 2020. How have the results been disseminated to communities of interest?Poster presentation at thePlant and Animal Genome meeting in January 2020. What do you plan to do during the next reporting period to accomplish the goals?Final evaluations of ROS levels in treated and control cucumbers with and without the SNP associated with cold tolerance.
Impacts
What was accomplished under these goals?
A single nucleotide polymorphism (SNP) was identified in the chloroplast atpB gene and conditions a single amino-acid change. Chloroplast RNA-seq revealed that this SNP is not edited, and therefore it is the likely candidate gene for coldtolerance. Phenotypic evaluations established that the coldtolerance is due to recovery from the cold treatment, and there was no evidence of any "priming" for cold tolerance beforecold treatments. Nuclear RNA-seq supported recovery as the basis of cold tolerance. Work is underway to measure stress response factors to assess correlation between recovery and ROS levels.
Publications
|
Progress 12/15/15 to 12/14/20
Outputs
Target Audience:Research will be of interest to plant breeders and geneticists working on abiotic stress tolerances to aid growers dealing with changing climates. Changes/Problems:COVID-19 resulted in restricted access to university research facilities from March 2020 through to the end of the grant in December 2020. The student and post-doc were paid even though there was no access to laboratories or growth facilities until September 2020. No undergraduates were allowed to work through this entire period. The post-doc resigned in July 2020, and did little research from March to July 2020. After September, the graduate student was only allowed to work in research facilities with time restrictions to ensure only one person is in a lab facility or office at any given time. As a result, there were significant delays in progress towards research goals. Funds were exhausted by the end of December 2020, and although the PhD student successfully defended her thesis, some important experiments were not completed. What opportunities for training and professional development has the project provided?Graduate student and post doc gained experience with RNA-seq of organelles and nucleus, and analyses of gene expression profiles. Both gained experience with phenotypic evaluations and measurement of ROS across cold treated and control plantings. Graduate student presented research as the Plant and Animal Genome meeting in January 2020. How have the results been disseminated to communities of interest?Poster presentation at the Plant and Animal Genome meeting in January 2020. Two publications describing this research are being written for submission in early 2021. A PhD thesis of one graduate student was successfully defended and deposited in the University of Wisconsin library. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
A single nucleotide polymorphism (SNP) was identified in the chloroplast atpB gene and conditions a single amino-acid change. This amino-acid change is located at the interface between the alpha and beta subunits of the chloroplast atp gene, and could affect production and availability of ATP. Chloroplast RNA-seq revealed that this SNP is not edited, and therefore it is the likely candidate gene for cold tolerance. Phenotypic evaluations established that the maternally transmitted cold tolerance in 'Chipper' cucumber is due to recovery from the cold treatment, as opposed to any "priming" for cold tolerance before cold treatments. Susceptible cucumbers did not recover from cold treatments and either died or had growth significantly reduced. Nuclear RNA-seq supported recovery as the basis of cold tolerance in that gene expression profiles were very similar before and during cold treatments, and were significantly different after treatments. Measurement of reactive oxygen species (ROS) supported a cold recovery phenotype and ROS levels were much higher in cold susceptible genotypes after cold treatments compared with genotypes with 'Chipper' as the maternal parent. The SNP is the chloroplast atpB gene is a marker for cold tolerance and should be investigated in other species to determine if it is associated with cold tolerance more broadly.
Publications
- Type:
Other
Status:
Published
Year Published:
2019
Citation:
Wallace, L.T., and M.J. Havey. 2019. Studies on sporophytic development of cucumber microspores. Report of the Cucurbit Genetics Cooperative 42:13-18
- Type:
Theses/Dissertations
Status:
Published
Year Published:
2020
Citation:
Olberg, MW. 2020. Evaluation and elucidation of the genetic bases of maternally-inherited cold tolerance and parent-of-origin effects in cucumber (Cucumis sativus). PhD Thesis, University of Wisconsin-Madison
|
Progress 12/15/18 to 12/14/19
Outputs
Target Audience:
Nothing Reported
Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?One graduate student completed all the phenotype evaluations and sequencing of the chloroplast DNA and RNA. The post doc worked on nuclear RNA-seq of reciprocal hybrids with identical nuclear genotypes. 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?Detailed analyses of the amino acid differnece in the atpB proteiin by in silico analyses of its structure, as well as predicting any effect on active or interactive sites onthe protein. Nuclear gene expression differences may be validated by qPCR.
Impacts
What was accomplished under these goals?
A single nucleotide polymorphism (SNP) was identified in the chloroplast atpB gene that is the likely candidate gene for cold tolerance. The SNP conditions an amino acid change. The SNP is not edited. Phenotypic evaluations revealed that the cold tolerance is due to recovery from the cold treatment, and there was no evidence of any "priming" for cold tolerance before cold treatments. Subsequent work will focus on the protein change conditioned by the unique SNP.
Publications
|
Progress 12/15/17 to 12/14/18
Outputs
Target Audience:Aposter on this research was presented at the Plant and Animal Genome Conference in January 2018 and interactions and discussion occurred with researchers interested in abiotic stresstolerances in plants. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?The graduate student supported by this project attended the 2018 Plant and Animal Genome meeting and presented a poster. She also attended a meeting for project directors for NIFA Foundation Grant recipients, and interacted with other scientists. The student passed her comprehensive exam and has attained dissertator status, resulting in more time to complete research on this projec.t How have the results been disseminated to communities of interest?One poster was presented in 2018 and another poster with more current results will be presented at the 2019 PAG meeting. What do you plan to do during the next reporting period to accomplish the goals?Reciprocal hybrids from crossing of the doubled haploid (DH)resistant to cold with numerous cold-susceptible DHs will be evaluated to determine how much difference there is in the expression of cold tolerance across hybrids. RNA-seq will be completed on reciprocal hybrids showing significant cold tolerance to identify differentially expressed genes associated with the cold tolerant chloroplasts.
Impacts
What was accomplished under these goals?
A single nucleotide polymorphism (SNP)in one chloroplast gene distinguishes cold-tolerant from cold-susceptible cucumbers. This SNP causes a single amino acid change in the protein. RNA was isolated from chloroplasts and this SNP is not edited, so this amino acid change is the likely genetic basis for the cold tolerance. Reciprocal hybrids from double haploid cucumbers susceptible and resistant to cold were evaluated in replicated experiments and the cold tolerance is not uniform across all croses, but is always maternally transmitted.
Publications
|
Progress 12/15/16 to 12/14/17
Outputs
Target Audience:
Nothing Reported
Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Graduate student research training. The student will present a poster at the Plant and Animal Genome Conference in 2018 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?In the next year, we will focus on RNA analyses of chloroplast transcriptsof cold-tolerant and susceptible cucumber lines. We will determine the level and postions of RNA editing to establish if any differences occur after editing. We will also determine if the candidate SNP in the chloroplast DNA is edited.
Impacts
What was accomplished under these goals?
Chloroplast DNAs were purified from cold-tolerant and susceptible lines of cucumber. The cold-tolerant line has a single nucleotide polymorphism (SNP) in one of the subunits of atpase, which results in an amino acid change. This specific SNP is the candidate for cold tolerance.
Publications
|
Progress 12/15/15 to 12/14/16
Outputs
Target Audience:Cucumber breeders and producers. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?A graduate student was hired and she started on September 1, 2016. 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?We plan to complete next-generation sequencing of chloroplast DNAs from cold-tolerant and susceptible doubled-haploid lines, and evaluate for sublimons that may be associated with cold tolerance.
Impacts
What was accomplished under these goals?
Doubled haploid (DH) cucumber lines were produced and evaluated under cold stress. The DH from the heirloom cultivar 'Chipper' suffered significantly less damage by cold compared to other DH lines from cultivars 'Straight 8' and '9930'. Hybrids were made between the Chipper DH with the cold-susceptible DHs and evaluated for cold tolerance. The hybrids with Chipper as the maternal parent performed significantly better than the reciprocal hybrids. Chloroplast DNA was isolated from DHs of Chipper and Straight 8 for next-generation sequencing.
Publications
|
|