Progress 09/01/13 to 12/31/15
Outputs
Target Audience:Our target audience included the biomass and bioenergy research community and the sorghum research community. Changes/Problems:The major problem encountered was reduced survival and fertility of the mutant plants in the field during the first year . This forced us to make another 15,000 M1 lines in the second year at a lower Fast neutron dosage. This reduced the number of resources available for this pupose away from the DNA pooling. We compensated, however, for the lower 1st year numbers by an aggressive push in the second year. We now have approximately 45,000 mutant M3 families and 210 indexed mutants. This required only a 4 month non-cost extension from the originally planned reporting date. What opportunities for training and professional development has the project provided?This project provided training for one postdoctoral fellow and two high school summer interns. How have the results been disseminated to communities of interest?The results have been disseminated via international peer-reviewed publications, local and out of state seminars and via our laboratory web page. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
We have mutagenized over 40,000 M1 seeds in the first year and another 15,000 in the second year. With 20,000 M1 seeds previously mutagenized, we processed a total of 75,000 M1 seeds. This is considerably more than what we proposed to do at the start of this project. In the first year of this project, due to poor survival and low fertlity encountered in the field, the subsequent generations were lower than what we anticipated. We developed a substatial genomic resource, however, which promises to provide excellent functional genomics research material. A total of 3000 fertile M2 family seeds were obtained and these were screened in the field to generate approximately 45,000 M3 families, some of which with spectacular phenotypes. These phenotypes included increased biomass with more tillers (2-5 tillers per plant), thick stems and big leaves, dwarf plants, tall plants, early flowering, late flowering, albino leaves, leafy panicles, etc. We recorded 210 vegetative growth mutant phenotypes under long day field conditions that show clear segregation in the population. This suggested that the population is very efficient and can be screened for any desired phenotype under specific conditions, and hence a valuable resource for functional genomics studies, especially for biomass related traits. We also pooled genomic DNA from 1000 M2 families for reverse screening. PCR -based reverse screening of this pool for SbNS1 didn't yield a mutation in this gene. However, we cloned the two maize NS1-related sorghum genes, SbNS1 and SbNS2, and analyzed their expression pattern and phylogenetic relationship. SbNS2 appeared to be distant from NS1 and did not complement the tobacco lam1 mutant phenotype. For this reason, we focused our investigations on SbNS1. We made detailed molecular, evolutionary and functional analysis of SbNS1 comparing it with Arabidopsis PRS and Medicago WOX3. The results of this analysis will be submitted for publication to a reputable peer reviewed journal. We also identified three putative florigens in sorghum that control flowering time and photoperiod response. Photoperiod-mediated flowering time has proven to be the single most important determinant of biomass yield in sorghum. It has also shown that identification of the responsible genes is a key step in understanding the regulation of biomass yield. This finding has been accepted for publication in New Phytologist. We extrapolated the sorghum flowering work into switchgrass for proof-of-concept. We found that the homologue of SbFT1 also controlled flowering time in switchgrass. This work has just been submitted for publication to Plant Cell and Environment. This SEED grant has been very successful and helped us establish the fundamental framework for sorghum functional genomics. We are now in a very good position to submit standard proposals to NIFA and NSF.
Publications
- Type:
Journal Articles
Status:
Accepted
Year Published:
2015
Citation:
Tezera W. Wolabu, Fei Zhang, Lifang Niu, Shweta Kalve, Pooja Bhatnagar-Mathur, Michael G. Muszynski and Million Tadege (2015). Three FLOWERING LOCUS T-like genes function as potential florigens and mediate photoperiod response in sorghum. New Phytologist (in press).
- Type:
Journal Articles
Status:
Submitted
Year Published:
2016
Citation:
Lifang Niu, Chuanxiang Fu, Hao Lin,Yanqui Wu, ZengYu Wang, and Million Tadege (2016). Control of floral transition in the bioenergy crop switchgrass. Plant Cell & Environment (submitted).
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Progress 09/01/13 to 08/31/14
Outputs
Target Audience: The target audiences for this reporting period were the scientific research comminity. We made presentation at the Samuel Roberts Noble Foundation's Plant Biology Division 25th Anniversary (April 27th-29th)which consists of several nationally prominent scientists, postdoctoral researchers, research staff and students. The project is also made available to the wider sorghum and biomass research community through our University web site. Changes/Problems: The major problem encountered was unexpectedly reduced servival and fertility of mutant sorghum plants in the field. The mutants were generated with 40 Gy treatment optimized for 50% servival under greenhouse conditions. As mentioned earlier, we found that this rate of servival was highly reduced in the filed with a very high proportion of serviving plants failing to set viable seeds. To offset the reduced number of mutants we have, we are planning tomake another 15,000 M1 seeds generated by 30 Gy treatment and add screened M2 plants to the mutant pool. This is just to subsidize the number of mutant lines we have and not expected to alter the reporting requirements. What opportunities for training and professional development has the project provided? One postdoctoral fellow has been recruited in the second half of the first year and is being trained in sorghum genetics, genomics and molecular techniques and will continue working on the project to complet theplanned objectives in the remaining one year. The project also provided summer training opportunities for two high school students in sorghum DNA extraction, sample collection and biomelecular techniques. How have the results been disseminated to communities of interest? The results are being disseminated through seminar presentation and our web site, but when completed as planned, results will be made available to the larger research comminity through peer reviewed publication and conference presentations. What do you plan to do during the next reporting period to accomplish the goals? The major objective of this project is to generate a substantial deletion mutantpopulation in sorghum which will serve as a research tool and genomic resource for C4 biomass functional genomics research for the wider biomass research community and a resource that serves as a springboard to launch the PI's research career. Since the existing number of M2 mutants is going to be significantly lower than what we planned to successfully achieve this goal, we will mutagenize additional 15,000 M1 lines with a lower dose of 30 Gy this year. The M1 lines will be planted in the summer of 2015 to generate approxiamately 5000 fertile M2 familes. This will subsidize the existing population as we go forward in the project. We will continue extracting genomic DNA from the existing M2 lines to make the 5000 genomic DNA pools as planned. Also, about 5000 M2 families, 10 seeds per family, (approximately 50,000 seeds) will be screened in the field from the presently harvesting lines in the summer of 2015 to identify biomass mutants.
Impacts
What was accomplished under these goals?
We have mutagenized over 40,000 M1 seeds with fat neutron bomabrdment this season and together with 20,000 previously available M1 seeds, a total of 60,000 M1seeds were planted in the field in Lane, Oklahoma in the summer of 2014. The treatment was optimized for 50 percent survival under greenhouse conditions and the plan was to obtain 30,000 M2 families. However, due to differences in in greenhouse and field conditions, germination and survival was found to be less than 25 percent. Plants are still growing in the field but the numbers are going to be significantly lower than what we initially hoped for. A more significant problem also appeared to be fertility. Mutant plants appear to be significantly delayed in maturity and as a result, it is still not yet possible to evaluate the full effect of the fertility problem. But, on the basis of what we are seeing so far, most of the surviving plants are flowering but not setting seeds, which will further reduce the goal we want to achieve. We will know the exact number of fertile mutants produced in this round probably by the end of October 2014. For objective 2, we have collected leaf samples from approximately 15,000 mutant M2 lines based on their growth vigor. We have initiated extracting DNA from those lines which are confirmed to be fertile and are still waiting for others to mature. For those M2 plants that do not make seeds, DNA extraction is a waste of time and resources because we cannot trace back the mutant lines without viable M2 seeds. So, we will wait untill the plants set seeds and we will throw away the leaves from sterile plants. We have cloned two genes, SbNS1 and SbNS2, which are closely related to the maize genes NS1 and NS2. Reverse genetic screening of the SbNS1 and SbNS2 genes using the mutant genomic DNA pool will be conducted in the second year (2015) as planned for objective 4. Forward genetic screeningof biomass mutants for objective 3 will also be performed next year as planned.
Publications
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