Progress 03/01/22 to 02/28/23
Outputs
Target Audience:The target audiences of this research include vitamin A deficient populations, wheat growers and producers, nutritionists, consumers, researchers, and the general public. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?One postdoctoral scholar, two graduate students, and four undergraduate students have been trained on the project. They learned various techniques on molecular biology, biochemistry, and plant breeding. They have also been trained with writing scientific publications. How have the results been disseminated to communities of interest?The PD discussed this research in the undergraduate course "Plants and Society" that she instructed in Fall quarters. The PD and the graduate student developed two new course modules and published two articles on Expanding the reach of crop plants for food security: A lesson integrating non-majors students into the discussion of food diversity and human nutrition (published) and Advancing global learning through a Collaborative Online International Learning (COIL) module on the United Nations Sustainable Development Goals (UN SDGs) (published). The PD, the postdoctoral scholar, and the graduate students presented the work nationally and internationally at scientific conferences, symposia, and seminar series. What do you plan to do during the next reporting period to accomplish the goals?This is the final report of the research project. We have already published five peer-reviewed research articles and four review articles germane to this research, with an additional manuscript being prepared for publication.
Impacts
What was accomplished under these goals?
Objective 1. Define the contribution of lycopene epsilon-cyclase (LCYe), beta-carotene hydroxylases (HYD) and carotenoid cleavage dioxygenases (CCD) to beta-carotene accumulation in tetraploid wheat grains (Years 1&2). -100% completion. We isolated and characterized tetraploid wheat TILLING mutants of the LCYe-A, LCYe-B, HYD-A1, HYD-B1, HYD-A2, HYD-B2, CCD-A1, CCD-B1, CCD-A4, and CCD-B4 homoeologs. Carotenoid profiles of vegetative tissues and grains were analyzed and compared for the mutant lines and the wild-type plants in the segregating population (i.e. wild-type controls). In addition, expression levels of the carotenoid metabolic gene homoeologs were determined in vegetative tissues and grains of the mutants and the wild-type plants using real-time qPCR. Overall, we did not observe significant changes in carotenoid composition and content, carotenoid metabolic gene expression, and growth and development in these single mutants as compared to the wild-type controls. This suggests that overlapping functions exist between the two homoeologs of each gene, which may compensate for the lesion in one of the homoeologs in the single mutant. Objective 2. Determine the combinatorial and/or synergistic effects of mutants defective in multiple carotenoid metabolic gene homoeologs on beta-carotene accumulation (Years 1-4). -100% completion. We completed physiological and biochemical characterization of the HYD and LCYe mutants and combinations (single, double, triple, and quadruple mutants). In addition, we generated and identified homozygous single, double, triple, and quadruple mutants of the HYD1 and HYD2 homoeologs and have dissected the function of HYD genes and homoeologs for carotenoid accumulation in wheat tissues. We selected tetraploid wheat TILLING mutant combinations that showed increased endosperm beta-carotene accumulation for further physiological and agronomic evaluations. We have completed data analysis and published two manuscripts on this work: Assessing the role of Carotenoid Cleavage Dioxygenase 4 homoeologs in carotenoid accumulation and plant growth in tetraploid wheat (published) and Mutational analysis of a wheat O-methyltransferase involved in flavonoid metabolism (published). Objective 3. Perform biochemical and agronomic evaluation of vitamin A biofortified tetraploid wheat (Years 3&4). -100% completion. We completed gene expression and carotenoid profiles in vegetative tissues and grains of the control, double, triple, and quadruple mutants of LCYe and HYD homoeologs. We also assessed the photosynthetic performance of these plants as well as seed germination, water loss and starch analysis. We published two articles on physiological and biochemical characterization of the provitamin A biofortified wheat plants as well as genetic dissection of the HYD mutant combinations: Mutant combinations of lycopene epsilon-cyclase and beta-carotene hydroxylase 2 homoeologs increased beta-carotene accumulation in endosperm of tetraploid wheat (Triticum turgidum L.) grains (published), and Genetic dissection of the role of beta-hydroxylases in carotenoid metabolism, photosynthesis, and plant growth in tetraploid wheat (Triticum turgidum L.) (published). Due to the pandemic situation in 2020 and 2021 and following the campus guideline on ramped down research activities, we were not able to conduct agronomic evaluation of vitamin A biofortified tetraploid wheat plants in Year 4 and part of Year 5. We conducted seed increase (in preparation for field trials) in summer 2021. We were able to perform two field trials in 2022: one in Davis, California and the other in Tulelake, California. The third field trial in Davis, California will be completed in June 2023. We will complete the agronomic evaluation of provitamin A biofortified tetraploid wheat after collecting and analyzing data from all three field trials. A manuscript describing this study will be submitted to publication.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2023
Citation:
Bekkering, C., Yu, S., Isaka, N.N., Sproul, B.W., Dubcovsky, J., and Tian, L. (2023) Genetic dissection of the role of beta-hydroxylases in carotenoid metabolism, photosynthesis, and plant growth in tetraploid wheat (Triticum turgidum L.). Theoretical and Applied Genetics. DOI 10.1007/s00122-023-04276-3
- Type:
Journal Articles
Status:
Accepted
Year Published:
2023
Citation:
Bekkering, C., Peng, C.S., and Tian, L. (2023) Advancing global learning through a Collaborative Online International Learning (COIL) module on the United Nations Sustainable Development Goals (UN SDGs). CourseSource. Accepted.
|
Progress 03/01/17 to 02/28/23
Outputs
Target Audience:The target audiences of this research include vitamin A deficient populations, wheat growers and producers, nutritionists, consumers, researchers, and the general public. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?One postdoctoral scholar, two graduate students, and four undergraduate students have been trained on the project. They learned various techniques on molecular biology, biochemistry, and plant breeding. They have also been trained with writing scientific publications. How have the results been disseminated to communities of interest?The PD discussed this research in the undergraduate course "Plants and Society" that she instructed in Fall quarters. The PD and one of the graduate students developed two new course modules and published two articles on Expanding the reach of crop plants for food security: A lesson integrating non-majors students into the discussion of food diversity and human nutrition (published) and Advancing global learning through a Collaborative Online International Learning (COIL) module on the United Nations Sustainable Development Goals (UN SDGs) (published). The PD, the postdoctoral scholar, and the graduate students presented the work nationally and internationally at scientific conferences, symposia, and seminar series. 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. Define the contribution of lycopene epsilon-cyclase (LCYe), beta-carotene hydroxylases (HYD) and carotenoid cleavage dioxygenases (CCD) to beta-carotene accumulation in tetraploid wheat grains (Years 1&2). -100% completion. We isolated and characterized tetraploid wheat TILLING mutants of the LCYe-A, LCYe-B, HYD-A1, HYD-B1, HYD-A2, HYD-B2, CCD-A1, CCD-B1, CCD-A4, and CCD-B4 homoeologs. Carotenoid profiles of vegetative tissues and grains were analyzed and compared for the mutant lines and the wild-type plants in the segregating population (i.e. wild-type controls). In addition, expression levels of the carotenoid metabolic gene homoeologs were determined in vegetative tissues and grains of the mutants and the wild-type plants using real-time qPCR. Overall, we did not observe significant changes in carotenoid composition and content, carotenoid metabolic gene expression, and growth and development in these single mutants as compared to the wild-type controls. This suggests that overlapping functions exist between the two homoeologs of each gene, which may compensate for the lesion in one of the homoeologs in the single mutant. Objective 2. Determine the combinatorial and/or synergistic effects of mutants defective in multiple carotenoid metabolic gene homoeologs on beta-carotene accumulation (Years 1-4). -100% completion. We completed physiological and biochemical characterization of the HYD and LCYe mutants and combinations (single, double, triple, and quadruple mutants). In addition, we generated and identified homozygous single, double, triple, and quadruple mutants of the HYD1 and HYD2 homoeologs and have dissected the function of HYD genes and homoeologs for carotenoid accumulation in wheat tissues. We selected tetraploid wheat TILLING mutant combinations that showed increased endosperm beta-carotene accumulation for further physiological and agronomic evaluations. We have completed data analysis and published two manuscripts on this work: Assessing the role of Carotenoid Cleavage Dioxygenase 4 homoeologs in carotenoid accumulation and plant growth in tetraploid wheat (published) and Mutational analysis of a wheat O-methyltransferase involved in flavonoid metabolism (published). Objective 3. Perform biochemical and agronomic evaluation of vitamin A biofortified tetraploid wheat (Years 3&4). -100% completion. We completed gene expression and carotenoid profiles in vegetative tissues and grains of the control, double, triple, and quadruple mutants of LCYe and HYD homoeologs. We also assessed the photosynthetic performance of these plants as well as seed germination, water loss and starch analysis. We published two articles on physiological and biochemical characterization of the provitamin A biofortified wheat plants as well as genetic dissection of the HYD mutant combinations: Mutant combinations of lycopene epsilon-cyclase and beta-carotene hydroxylase 2 homoeologs increased beta-carotene accumulation in endosperm of tetraploid wheat (Triticum turgidum L.) grains (published), and Genetic dissection of the role of beta-hydroxylases in carotenoid metabolism, photosynthesis, and plant growth in tetraploid wheat (Triticum turgidum L.) (published). Due to the pandemic situation in 2020 and 2021 and following the campus guideline on ramped down research activities, we were not able to conduct agronomic evaluation of vitamin A biofortified tetraploid wheat plants in Year 4 and part of Year 5. We conducted seed increase (in preparation for field trials) in summer 2021. We were able to perform two field trials in 2022: one in Davis, California and the other in Tulelake, California. The third field trial in Davis, California will be completed in June 2023. We will complete the agronomic evaluation of provitamin A biofortified tetraploid wheat after collecting and analyzing data from all three field trials. A manuscript describing this study will be submitted to publication.
Publications
|
Progress 03/01/21 to 02/28/22
Outputs
Target Audience:The target audience of this research include wheat geneticists and breeders, plant biologists working in the field of plant metabolism, nutritionists, as well as consumers. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?One postdoctoral scholar, two graduate students, and four undergraduate students have been trained on the project. They learned various techniques on molecular biology, biochemistry, and plant breeding. They have also been trained with writing scientific publications. How have the results been disseminated to communities of interest?The PD and a graduate student developed a new course module and published an article on expanding the reach of crop plants for food security: A lesson integrating non-majors students into the discussion of food diversity and human nutrition. The postdoctoral scholar presented the work at two scientific conferences. What do you plan to do during the next reporting period to accomplish the goals?We plan to complete agronomic evaluation of wheat TILLING mutant combinations that show increased endosperm b-carotene accumulation and prepare a manuscript for publication. We will also complete the manuscript on dissecting the function of HYD genes and homoeologs for carotenoid accumulation in wheat for publication.
Impacts
What was accomplished under these goals?
Objective 1. Define the contribution of lycopene epsilon-cyclase (LCYe), beta-carotene hydroxylases (HYD) and carotenoid cleavage dioxygenases (CCD) to beta-carotene accumulation in tetraploid wheat grains (Years 1&2). -100% completion. We isolated and characterized tetraploid wheat TILLING mutants of the LCYe-A, LCYe-B, HYD-A1, HYD-B1, HYD-A2, HYD-B2, CCD-A1, CCD-B1, CCD-A4, and CCD-B4 homoeologs. Carotenoid profiles of vegetative tissues and grains were analyzed and compared for the mutant lines and the wild-type plants in the segregating population (i.e. wild-type controls). In addition, expression levels of the carotenoid metabolic gene homoeologs were determined in vegetative tissues and grains of the mutants and the wild-type plants using real-time qPCR. Overall, we did not observe significant changes in carotenoid composition and content, carotenoid metabolic gene expression, and growth and development in these single mutants as compared to the wild-type controls. This suggests that overlapping functions exist between the two homoeologs of each gene, which may compensate for the lesion in one of the homoeologs in the single mutant. Objective 2. Determine the combinatorial and/or synergistic effects of mutants defective in multiple carotenoid metabolic gene homoeologs on beta-carotene accumulation (Years 1-4). -100% completion. We completed physiological and biochemical characterization of the HYD and LCYe mutants and combinations (single, double, triple, and quadruple mutants). In addition, we generated and identified homozygous single, double, triple, and quadruple mutants of the HYD1 and HYD2 homoeologs and have dissected the function of HYD genes and homoeologs for carotenoid accumulation in wheat tissues. We selected tetraploid wheat TILLING mutant combinations that showed increased endosperm beta-carotene accumulation for further physiological and agronomic evaluations. We have completed data analysis and published two manuscripts on this work: Assessing the role of Carotenoid Cleavage Dioxygenase 4 homoeologs in carotenoid accumulation and plant growth in tetraploid wheat (published) and Mutational analysis of a wheat O-methyltransferase involved in flavonoid metabolism (published). Objective 3. Perform biochemical and agronomic evaluation of vitamin A biofortified tetraploid wheat (Years 3&4). -60% completion. We completed gene expression and carotenoid profiles in vegetative tissues and grains of the control, double, triple, and quadruple mutants of LCYe and HYD homoeologs. We also assessed the photosynthetic performance of these plants as well as seed germination, water loss and starch analysis. We published an article on physiological and biochemical characterization of the provitamin A biofortified wheat plants: Mutant combinations of lycopene e-cyclase and b-carotene hydroxylase 2 homoeologs increased b-carotene accumulation in endosperm of tetraploid wheat (Triticum turgidum L.) grains. Due to the pandemic situation in 2020 and 2021 and following the campus guideline on ramped down research activities, we were not able to conduct agronomic evaluation of vitamin A biofortified tetraploid wheat plants in Year 4 and part of Year 5. We conducted seed increase (in preparation for field trials) in summer 2021. We were able to start the first field trial in November 2021 (ongoing). A second field trial is planned for summer 2022. We will complete the agronomic evaluation of provitamin A biofortified tetraploid wheat after collecting and analyzing data from the two field trials.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2021
Citation:
Yu, S. and Tian, L. (2021) Assessing the role of Carotenoid Cleavage Dioxygenase 4 homoeologs in carotenoid accumulation and plant growth in tetraploid wheat. Frontiers in Nutrition 8:740286.
- Type:
Journal Articles
Status:
Published
Year Published:
2021
Citation:
Yu, S., Bekkering, C.S., and Tian, L. (2021) Metabolic engineering in woody plants: challenges, advances, and opportunities. aBIOTECH 2: 299-313.
- Type:
Journal Articles
Status:
Published
Year Published:
2021
Citation:
Yu, S., Li, M., Dubcovsky, J., and Tian, L. (2021) Mutant combinations of lycopene epsilon-cyclase and beta-carotene hydroxylase 2 homoeologs increased beta-carotene accumulation in endosperm of tetraploid wheat (Triticum turgidum L.) grains. Plant Biotechnology Journal. https://doi.org/10.1111/pbi.13738
- Type:
Journal Articles
Status:
Published
Year Published:
2022
Citation:
Cain, A.B., Yu, S., and Tian, L. (2022) Mutational analysis of a wheat O-methyltransferase involved in flavonoid metabolism. Plants. 11: 164.
|
Progress 03/01/20 to 02/28/21
Outputs
Target Audience:The target audience of this research include wheat geneticists and breeders, plant biologists working in the field of plant metabolism, nutritionists, as well as consumers. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?One postdoctoral scholar, two graduate students, and two undergraduate students have been trained on the project. They learned various techniques on molecular biology, biochemistry, and plant breeding. They have also been trained with writing scientific publications. How have the results been disseminated to communities of interest?The PD discussed this research in the undergraduate course "Plants and Society" that she instructed in Fall 2020. The PD and a graduate student developed a new course module and published an article on expanding the reach of crop plants for food security: A lesson integrating non-majors students into the discussion of food diversity and human nutrition. What do you plan to do during the next reporting period to accomplish the goals?In Year 5, wheat TILLING mutant combinations that show increased endosperm b-carotene accumulation will be subjected to agronomic evaluations. We will complete the manuscript on dissecting the function of HYD genes and homoeologs for carotenoid accumulation in wheat for publication.
Impacts
What was accomplished under these goals?
Objective 1. Define the contribution of lycopene epsilon-cyclase (LCYe), beta-carotene hydroxylases (HYD) and carotenoid cleavage dioxygenases (CCD) to beta-carotene accumulation in tetraploid wheat grains (Years 1&2). -100% completion. During the second year of this project, we further characterized tetraploid wheat TILLING mutants of the LCYe-A, LCYe-B, HYD-A1, HYD-B1, HYD-A2, HYD-B2, CCD-A1, CCD-B1, CCD-A4, and CCD-B4 homoeologs, which were isolated and backcrossed to the wild type parental line Kronos in Year 1. Carotenoid profiles of vegetative tissues and grains were analyzed and compared for the mutant lines and the wild type plants in the segregating population (i.e. wild type controls). In addition, expression levels of the carotenoid metabolic gene homoeologs were determined in vegetative tissues and grains of the mutants and the wild type plants using real-time qPCR. Overall, we did not observe significant changes in carotenoid composition and content, carotenoid metabolic gene expression, and growth and development in these single mutants as compared to the wild type controls. This suggests that overlapping functions exist between the two homoeologs of each gene, which may compensate for the lesion in one of the homoeologs in the single mutant. Objective 2. Determine the combinatorial and/or synergistic effects of mutants defective in multiple carotenoid metabolic gene homoeologs on beta-carotene accumulation (Years 1-4). -95% completion. During the fourth year of this project, we completed physiological and biochemical characterization of the HYD and LCYe mutants and combinations (single, double, triple and quadruple mutants). We are preparing a manuscript on this study for publication. In addition, we generated and identified homozygous single, double, triple, and quadruple mutants of the HYD1 and HYD2 homoeologs and have dissected the function of HYD genes and homoeologs for carotenoid accumulation in wheat tissues. We are currently completing data analysis and writing a manuscript on this work. We selected tetraploid wheat TILLING mutant combinations that showed increased endosperm beta-carotene accumulation for further physiological and agronomic evaluations in Year 5. Objective 3. Perform biochemical and agronomic evaluation of vitamin A biofortified tetraploid wheat (Years 3&4). -40% completion. During the fourth year of this project, we completed gene expression and carotenoid profiles in vegetative tissues and grains of the control, double, triple, and quadruple mutants of LCYe and HYD homoeologs. We also assessed the photosynthetic performance of these plants as well as seed germination, water loss and starch analysis. Due to the pandemic situation in 2020 and following the campus guideline on ramped down research activities, we were not able to conduct agronomic evaluation of vitamin A biofortified tetraploid wheat plants in Year 4. Such analysis is now planned for Year 5 of the project. We published an article on expanding the reach of crop plants for food security: A lesson integrating non-majors students into the discussion of food diversity and human nutrition and an article on image-based, organ-level plant phenotyping for wheat improvement. We also collaborated with another group and published an article on marker-free carotenoid-enriched rice generated through targeted gene insertion using CRISPR-Cas9.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2020
Citation:
Bekkering, C.S., Huang, J. and Tian, L. (2020) Image-based, organ-level plant phenotyping for wheat improvement. Agronomy, 10: 1287.
- Type:
Journal Articles
Status:
Published
Year Published:
2020
Citation:
Bekkering, C.S. and Tian, L. (2020) Expanding the reach of crop plants for food security: A lesson integrating non-majors students into the discussion of food diversity and human nutrition. CourseSource. https://doi.org/10.24918/cs.2020.39.
- Type:
Journal Articles
Status:
Published
Year Published:
2020
Citation:
Dong, O., Yu, S., Jain, R., Zhang, N., Duong, P., Butler, C., Li, Y., Lipzen, A., Martin, J., Barry, K., Schmutz, J., Tian, L. and Ronald, P. (2020) Marker-free carotenoid-enriched rice generated through targeted gene insertion using CRISPR-Cas9. Nature Communications 11:1178.
|
Progress 03/01/19 to 02/29/20
Outputs
Target Audience:The target audience of this research include wheat geneticists and breeders, plant biologists working in the field of plant metabolism, nutritionists, as well as consumers. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?One postdoctoral scholar and one graduate student have been trained on the project. They learned various techniques on molecular biology, biochemistry, and plant breeding. They have also been trained with writing scientific publications. The PD also mentored an undergraduate student from California State University, Northridge [through the RISE (Research Training Initiative for Scientific Enhancement) program] on this research in summer 2019. How have the results been disseminated to communities of interest?The PD presented this work to researchers from INRA in March 2019 and BASF in June 2019. The PD discussed this research in the undergraduate course "Plants and Society" that she instructed in Fall 2019. The PD also discussed this research to colleagues from Historically Black Colleges and Universities (HBCU) in January 2019, and a group of HSI (Hispanic Serving Institution) STEM transfer students from Contra Costa College in April 2019. The PD presented this research at the 2019 ASPB meeting. What do you plan to do during the next reporting period to accomplish the goals?In Year 4, wheat TILLING mutant combinations that show increased endosperm b-carotene accumulation will be subjected to further biochemical, physiological and agronomic evaluations. Single, double, triple, and quadruple mutants of the HYD1 and HYD2 homoeologs will be characterized in parallel to dissect the function of the HYD genes and homoeologs for carotenoid accumulation in wheat tissues. We will also prepare manuscripts on generation and characterization of the TILLING mutants for publication.
Impacts
What was accomplished under these goals?
Objective 1. Define the contribution of lycopene epsilon-cyclase (LCYe), beta-carotene hydroxylases (HYD) and carotenoid cleavage dioxygenases (CCD) to beta-carotene accumulation in tetraploid wheat grains (Years 1&2). -100% completion. During the second year of this project, we further characterized tetraploid wheat TILLING mutants of the LCYe-A, LCYe-B, HYD-A1, HYD-B1, HYD-A2, HYD-B2, CCD-A1, CCD-B1, CCD-A4, and CCD-B4 homoeologs, which were isolated and backcrossed to the wild type parental line Kronos in Year 1. Carotenoid profiles of vegetative tissues and grains were analyzed and compared for the mutant lines and the wild type plants in the segregating population (i.e. wild type controls). In addition, expression levels of the carotenoid metabolic gene homoeologs were determined in vegetative tissues and grains of the mutants and the wild type plants using real-time qPCR. Overall, we did not observe significant changes in carotenoid composition and content, carotenoid metabolic gene expression, and growth and development in these single mutants as compared to the wild type controls. This suggests that overlapping functions exist between the two homoeologs of each gene, which may compensate for the lesion in one of the homoeologs in the single mutant. Objective 2. Determine the combinatorial and/or synergistic effects of mutants defective in multiple carotenoid metabolic gene homoeologs on beta-carotene accumulation (Years 1-4). -75% completion. During the third year of this project, we genotyped the progeny of TILLING mutant crosses between HYD and LCYe homoeologs and isolated homozygous double, triple and quadruple mutants. In addition, we analyzed gene expression and carotenoid profiles in vegetative tissues and grains of the above-mentioned mutants. We selected tetraploid wheat TILLING mutant combinations that showed increased endosperm beta-carotene accumulation for further physiological and agronomic evaluations in Year 4. Furthermore, we generated and identified homozygous single, double, triple, and quadruple mutants of the HYD1 and HYD2 homoeologs to dissect the function of HYD genes and homoeologs for carotenoid accumulation in wheat tissues. Objective 3. Perform biochemical and agronomic evaluation of vitamin A biofortified tetraploid wheat (Years 3&4). -25% completion. During the third year of this project, we analyzed gene expression and carotenoid profiles in vegetative tissues and grains of the control, double, triple, and quadruple mutants of LCYe and HYD homoeologs. We also assessed the photosynthetic performance of these plants. We propagated grains from the triple and quadruple mutants for downstream agronomic evaluations. We also published an article on leveraging the nutrients of cereal and pseudocereal grains for improving human nutrition and health.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2019
Citation:
Bekkering, C. and Tian, L. (2019) Thinking outside of the cereal box: Breeding underutilized (pseudo)cereals for improved human nutrition. Frontiers in Genetics 10:1289.
|
Progress 03/01/18 to 02/28/19
Outputs
Target Audience:The target audience of this research include wheat geneticists and breeders, plant biologists working in the field of plant metabolism, nutritionists, as well as consumers. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Two graduate students have been trained on the project. These students learned various techniques on molecular biology, biochemistry, and plant breeding. How have the results been disseminated to communities of interest?The PD presented this research to a delegation from the Commonwealth Scientific and Industrial Research Organization (CSIRO) in September 2018. The PD discussed this research in the undergraduate course "Plants and Society" that she instructed in Fall 2018. The PD also discussed this research to colleagues from Historically Black Colleges and Universities (HBCU) in January 2019. What do you plan to do during the next reporting period to accomplish the goals?In Year 3, we will conduct detailed molecular and biochemical characterization of the double, triple and quadruple TILLING mutant combinations generated in Objective 2. In addition, we will select tetraploid wheat TILLING mutant combinations that show increased endosperm beta-carotene accumulation for further physiological and agronomic evaluations in Year 3-4. We will also prepare manuscripts on characterization of the single and double mutants for publication.
Impacts
What was accomplished under these goals?
Objective 1. Define the contribution of lycopene epsilon-cyclase (LCYe), beta-carotene hydroxylases (HYD) and carotenoid cleavage dioxygenases (CCD) to beta-carotene accumulation in tetraploid wheat grains (Years 1&2). -100% completion. During the second year of this project, we further characterized tetraploid wheat TILLING mutants of the LCYe-A, LCYe-B, HYD-A1, HYD-B1, HYD-A2, HYD-B2, CCD-A1, CCD-B1, CCD-A4, and CCD-B4 homoeologs, which were isolated and backcrossed to the wild type parental line Kronos in Year 1. Carotenoid profiles of vegetative tissues and grains were analyzed and compared for the mutant lines and the wild type plants in the segregating population (i.e. wild type controls). In addition, expression levels of the carotenoid metabolic gene homoeologs were determined in vegetative tissues and grains of the mutants and the wild type plants using real-time qPCR. Overall, we did not observe significant changes in carotenoid composition and content, carotenoid metabolic gene expression, and growth and development in these single mutants as compared to the wild type controls. This suggests that overlapping functions exist between the two homoeologs of each gene, which may compensate for the lesion in one of the homoeologs in the single mutant. Objective 2. Determine the combinatorial and/or synergistic effects of mutants defective in multiple carotenoid metabolic gene homoeologs on beta-carotene accumulation (Years 1-4). -50% completion. In addition to the double mutants of HYD-A1/HYD-B1, HYD-A2/HYD-B2, CCD-A1/CCD-B1, CCD-A4/CCD-B4, and LCYe-A/LCYe-B established in Year 1, we generated and genotyped the triple mutants of LCYe-A/HYD-A1/HYD-B1 and LCYe-A/HYD-A2/HYD-B2, and identified homozygous mutants of each line. The triple mutants of LCYe-A/CCD-A1/CCD-B1, HYD-A1/HYD-B1/HYD-A2, HYD-A1/HYD-B1/HYD-B2, HYD-A1/HYD-A2/HYD-B2, and HYD-B1/HYD-A2/HYD-B2, and the quadruple mutants of HYD-A1/HYD-B1/HYD-A2/HYD-B2 and LCYe-A/LCYe-B/HYD-A2/HYD-B2 have also been generated; we are currently genotyping the progeny of these triple and quadruple mutant crosses. In addition, we have analyzed gene expression and carotenoid profiles in vegetative tissues and grains of the HYD-A1/HYD-B1, HYD-A2/HYD-B2, and LCYe-A/HYD-A2/HYD-B2 mutants. Objective 3. Perform biochemical and agronomic evaluation of vitamin A biofortified tetraploid wheat (Years 3&4). -0% completion. This objective will be initiated in Year 3-4 of the project timeline and there is nothing to report at this time.
Publications
|
Progress 03/01/17 to 02/28/18
Outputs
Target Audience:The target audience of this research include wheat geneticists and breeders, plant biologists working in the field of plant metabolism, nutritionists, as well as consumers. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Two graduate students and one undergraduate student have been trained on the project. These students learned various techniques on molecular biology, biochemistry and breeding. How have the results been disseminated to communities of interest?We published one research article. A graduate student presented this work at the Sixth Annual University of California, Davis Plant Sciences Symposium in April 2017 (poster presentation, Davis, CA) and the Annual Meeting of National Association of Plant Breeders in August 2017 (poster presentation, Davis, CA). The PD presented this research at the annual USDA-NIFA Project Director's meeting in January 2018 (poster presentation, San Diego, CA), the 26th Plant and Animal Genome conference in January 2018 (poster presentation, San Diego, CA), and International Wheat Yield Partnership Project Director meeting in January 2018 (oral presentation, San Diego, CA). What do you plan to do during the next reporting period to accomplish the goals?In year 2, we will complete functional characterization of all the single tetraploid wheat TILLING mutants as outlined in Objective 1. In addition, we will continue with detailed biochemical characterization of the double and triple TILLING mutant combinations as outlined in Objective 2. Tetraploid wheat TILLING mutant combinations that show increased endosperm beta-carotene accumulation will be selected for further physiological and agronomic evaluations and used for developing vitamin A biofortified wheat varieties in years 3 and 4.
Impacts
What was accomplished under these goals?
Objective 1. Define the contribution of lycopene epsilon-cyclase (LCYe), beta-carotene hydroxylases (HYD) and carotenoid cleavage dioxygenases (CCD) to beta-carotene accumulation in tetraploid wheat grains (Years 1&2). -50% completion. During the first year of this project, we have identified tetraploid wheat TILLING mutants of the LCYe-A, LCYe-B, HYD-A1, HYD-B1, HYD-A2, HYD-B2, CCD-A1, CCD-B1, CCD-A4, and CCD-B4 homoeologs, which allow us to functionally characterize these carotenoid metabolic gene homoeologs as well as genetically define their contribution to beta-carotene accumulation in wheat grains. These mutant alleles were amplified from the respective wheat TILLING mutant plants and cloned into a bacterial expression vector. Loss or reduced function of the mutant alleles was verified using a bacterial system that has been engineered for carotenoid accumulation and transformed with plasmids expressing mutant alleles of the carotenoid metabolic gene homoeologs. We also backcrossed these single mutants to the wild type parental line Kronos to reduce background mutations. Homozygous BC1 or higher progenies (i.e. at least 50% Kronos background recovered) of the above-mentioned TILLING mutants have already been generated. So far, we have analyzed carotenoid profiles in leaves and grains of the HYD-A1, HYD-B1, HYD-A2, and HYD-B2 single mutants. We did not observe significant changes in carotenoid composition and content in these mutants as compared to the wild type controls, suggesting that the overlapping functions among HYD1 and HYD2 genes and homoeologs may compensate for the lesion in one of the HYD1/2 gene homoeologs. The single tetraploid wheat TILLING mutants of LCYe-A, LCYe-B, CCD-A1, CCD-B1, CCD-A4, and CCD-B4 are currently growing in the greenhouse. Leaf and grain tissues will be collected and analyzed for carotenoid profiles. In year 1, we have also optimized a method for quantification of ABA concentrations in wheat grains. Objective 2. Determine the combinatorial and/or synergistic effects of mutants defective in multiple carotenoid metabolic gene homoeologs on beta-carotene accumulation (Years 1-4). -25% completion. During year 1, we generated double mutants of HYD-A1/HYD-B1, HYD-A2/HYD-B2, CCD-A1/CCD-B1, CCD-A4/CCD-B4, and LCYe-A/LCYe-B. We have completed genotyping progeny of the double mutant crosses and identified homozygous double mutants of each mutant combination. We also generated triple mutants of LCYe-A/HYD-A1/HYD-B1 and LCYe-A/HYD-A2/HYD-B2. We are currently genotyping progeny of these triple mutant crosses. Objective 3. Perform biochemical and agronomic evaluation of vitamin A biofortified tetraploid wheat (Years 3&4). -0% completion. This objective will be initiated in Year 3-4 of the project timeline and there is nothing to report at this time.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2018
Citation:
Yu, S. and Tian, L. (2018) Breeding major cereal grains through the lens of nutrition sensitivity. Molecular Plant 11, 23-30.
https://doi.org/10.1016/j.molp.2017.08.006
|
|