Progress 04/01/11 to 03/31/15
Outputs
Target Audience: Target audiences reached during the reporting period included plant scientists that work on assimilate partitiong and its role in plant growth and graduate students. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided? Both graduate students and the postdoc that have worked on this project have enhanced their experience by learning how to measure physiological parameters of growth, biochemical assays of sugars and how to make transgenic plants (from making the expression casettes via recombinat DNA tehcniques) and measure gene expression. How have the results been disseminated to communities of interest? Results have been disseminated by publication and public presentations to the plant science community. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
In our 2014 experiment, we grew both transgenic sugar beet and rice in the green house with supplemental phosphate. This was in response to a report in Arabidopsis that over expressing the sucrose transporter resulted in phosphate deficiency symptoms. We monitored phosphate levels throughout the growth period and adjusted them as needed, but again failed to measure any increase in yield or photosynthesis. One possible explanation is that both control and transgenic plants are growing at their maximum under the optimum growth conditions in the green house. One way to test this hypothesis is to grow both controls and transgenic plants in elevated CO2 where photosynthetic rates are increased by >20% to see increased carbon fixation separates the control from the over expresser. We are collaborating with a team of plant scientists at the Univ. of Illinois, and will be testing that idea with control and over expressing sugar beet next summer (2016) in their FACE rings in Illinois. As noted under the products section, we discovered a novel gene that when over expressed, enhances yield and plant resistance to biotic stress. We are validating those observations by duplicating the over expression phenotype. We will be seeking grant support to fully investigate the mechanism underlying this phenotype.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2011
Citation:
Ainsworth EA and Bush DR 2011. Carbohydrate export from the leaf - A highly regulated process and target to enhance photosynthesis and productivity. Plant Physiology 155: 157-168
- Type:
Book Chapters
Status:
Published
Year Published:
2013
Citation:
Harrington GN and Bush DR 2013. Transport proteins in plant growth and development. In: Sugarcane: Physiology, Biochemistry and Functional Biology. Eds. Paul H. Moore and Frederik C. Botha, p. 255-265, Wiley Publishing
- Type:
Journal Articles
Status:
Published
Year Published:
2015
Citation:
Yadav UP, Ayre BG, Bush DR 2015. Transgenic approaches to altering carbon and nitrogen partitioning in whole plants: assessing the potential to improve crop yields and nutritional quality. Frontiers in Plant Science. 2015 Vol. 6/ Article 275
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Progress 04/01/13 to 03/31/14
Outputs
Target Audience:
Nothing Reported
Changes/Problems: Testing new promoter for actvity and increasing phosphate to avoid deficiency responses that may decrease growth. What opportunities for training and professional development has the project provided? Training and professional development: For CO-Pi - experience co-direcxting project and coordinating graduate student work For graduate students - learned new techniques for measuring gene expression and measuring different parameters of plant growth. 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? As noted above - growing plants with new promoter constructs and monitoring phosphate availability.
Impacts
What was accomplished under these goals?
The objective of this project is to use a biotech approach to increase sucrose transport in the plants vascular system so that sugar levels in the leaf will drop and, thereby, increase photosynthesis. Over a full season, this is hypothesized to increase yield. During this period (4/13 - 3/14), we grew transgenic sugar beet over-expressing the sucrose transporter using galactinol synthase companion cell specific promoter. We also developed new transgenic sugar beets with a different companion cell specific promoter. Sugar beet plants were grown in a hydroponic system to maximize growth and score the transgenic plants for changes in yield. We also grew transgenic rice that over-express the sucrose transporter in the phloem. The transgenic rice were generated using a tissue culture system. Results from the 2013 summer season for the sugar beet did not yield a difference in yield. However, in spite of demonstrating expression of the transgene in young plants, we discovered the transgene was silenced by the end of the experiment. We are using plants with a different companion cell specific promoter this summer (summer 2014), and monitoring expression throughout the season. The transgenic rice plants in 2013, had lower yield and biomass than the wild type. We recent publication with Arabidopsis plants over-expressing the same sucrose transporter reported high sucrose turned on phosphate deficiency response and lowered growth. In light of that report, we are increasing phosphate availability and we'll monitor the expression of deficiency genes to make sure we maintain sufficient levels of phosphate.
Publications
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Progress 04/01/12 to 03/31/13
Outputs
OUTPUTS: The objective of this project is to use a biotech approach to increase sucrose transport in the plants vascular system so that sugar levels in the leaf will drop and, thereby, increase photosynthesis. Over a full season, this is hypothesized to increase yield. During this period, we tested a hydroponic system for growing transgenic sugar beet plants to maximize growth and score the transgenic plants for changes in yield. We also created new transgenic sugar beet that over-expresses a sucrose transporter using a different selectable marker then our first plants. Seeds for these plants should be available this (2013) summer. Finally, we made a new expression vector to over-express the same transporter in rice. Transgenic rice were generated using a tissue culture system and we should be harvesting seed soon. PARTICIPANTS: PI - Daniel Bush helped plan the experiment and analyze the data. Co-PI - Bettina Broeckling helped plan the experiment, worked on the plants in the green house, collected data and helped analyze the results. Vince Stoerger and Seungho Jung are graduate students that assisted in all aspects of running the experiment, including growing the plants, measuring physiological traits, harvesting beets and leaf tissue and data acquisition. They also assisted in data analysis. TARGET AUDIENCES: The target audiences include plant scientists, agronomists, and the sugar beet industry. PROJECT MODIFICATIONS: As noted in the outcomes of this years report, we demonstrated superior plant growth in the green house when plants were grown with a hydroponic system. We we modify it for optimum growth and use it in all future experiments.
Impacts
We successfully generated the necessary experimental sugar beet and rice plants to test our basic hypothesis this last year. We also tested a hydroponic systems to maximize growth in green house conditions. The system was so successful, the plants were much larger than pot grown plants and spacing between individuals led to shading between plants. This lowered light interception and lowered yield for interior plants relative to ones on the edges of the growth system. A new planting pattern with much more room around every plant will eliminate this problem in future experiments.
Publications
- No publications reported this period
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Progress 04/01/11 to 03/31/12
Outputs
OUTPUTS: During the summer of 2011 we conducted a growth experiment with control and transgenic sugar beet that over-express the sucrose transporter that loads the phloem. We analyzed the data in the fall and winter of 2011/2012. A summary of the results was submitted to the plant biology leaders at AFRI in preparation for a Program Director meeting in May of 2012. PARTICIPANTS: PI - Daniel Bush helped plan the experiment and analyze the data. Co-PI - Bettina Broeckling helped plan the experiment, worked on the plants in the green house, collected data and helped analyze the results. Vince Stoerger and Seungho Jung are graduate students that assisted in all aspects of running the experiment, including growing the plants, measuring physiological traits, harvesting beets and leaf tissue and data acquisition. They also assisted in data analysis. TARGET AUDIENCES: The target audiences include plant scientists, agronomists, and the sugar beet industry. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
The data from the 2011 experiment showed no difference in yield or growth of the transgenic plants compared to wild type plants grown in a common garden green house experiment. However, we did observe pot binding of all plants even though the beets were grown individually in 20 gallon containers. We concluded the primary root hit the bottom of the pot and sent a signal that suppressed the development of the sucrose storing beet. To avoid this problem in the 2012 experiment, plants will be grown hydroponically in a large tank where beet development and sucrose storage is normal.
Publications
- No publications reported this period
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