Emerging Researchers National (ERN) Conference

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FIS2-Dependent Down-Regulation of Invertase Inhibitors During Arabidopsis Seed Development

Undergraduate #128
Discipline: Biological Sciences
Subcategory: Plant Research

Mason Dana - Spelman College
Co-Author(s): Dongfang Wang, Spelman College, Atlanta, GA


Endosperm is a large source of calories in human diets. Therefore, it is important to study the mechanisms responsible for its early growth and development. After fertilization, the endosperm goes through free nuclear divisions resulting in a non-cellularized syncytium, which is followed by a cellularized phase. Embryo growth increases dramatically after endosperm cellularization. Since invertase catalyzes the hydrolysis of sucrose into glucose and fructose, which are used as energy in plant cells, we investigated whether changes in embryo growth rate are associated with changes in invertase activity. Our data indicated that invertase inhibitors are highly expressed before cellularization and down-regulated after cellularization. Endosperm cellularization requires FIS2, which is a polycomb group protein that represses gene expression. To test whether FIS2 represses the expression of invertase inhibitors, we used RT -PCR and qPCR to measure the expression level of invertase inhibitors at different stages of seed development. The expression of invertase inhibitors was detected after fertilization in both the wild type and fis2 mutant plants. However, the down -regulation of invertase inhibitors was only observed in the wild type plants. In addition to the PCR’s, we also analyzed the invertase inhibitor promoter activity in fis2 mutant using a promoter-GFP reporter. The promoter activity was detected during the syncytial phase and failed to be down-regulated in fis2 mutant. Our data suggested that FIS2 represses the expression of invertase inhibitors, thus promoting embryo growth after endosperm cellularization. Unlocking the mechanisms of gene regulation during seed development could ultimately have a big impact on how we grow our crops.

Funder Acknowledgement(s): This investigation was supported by an HBCU-UP Award from the National Science Foundation, Award ID:1436759.

Faculty Advisor: Dongfang Wang,

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This material is based upon work supported by the National Science Foundation (NSF) under Grant No. DUE-1930047. Any opinions, findings, interpretations, conclusions or recommendations expressed in this material are those of its authors and do not represent the views of the AAAS Board of Directors, the Council of AAAS, AAAS’ membership or the National Science Foundation.