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ARS Home » Midwest Area » Lexington, Kentucky » Forage-animal Production Research » Research » Publications at this Location » Publication #333293
Title: KELCH F-BOX protein positively influences Arabidopsis seed germination by targeting PHYTOCHROME-INTERACTING FACTOR1

Author
item MAJEE, MANOJ - University Of Kentucky
item KUMAR, SANTOSH - University Of Kentucky
item KATHARE, PRAVEEN - University Of Texas At Austin
item WU, SHUIQIN - University Of Kentucky
item GINGERICH, DEREK - University Of Wisconsin
item NAYAK, NIHAR - University Of Kentucky
item SALAITA, LOUAI - University Of Kentucky
item Dinkins, Randy
item MARTIN, KATHLEEN - University Of Kentucky
item GOODIN, MICHAEL - University Of Kentucky
item DIRK, LYNNETTE - University Of Kentucky
item LLOYD, TAYLOR - University Of Kentucky
item ZHU, LING - University Of Texas At Austin
item CHAPPELL, JOE - University Of Kentucky
item HUNT, ARTHUR - University Of Kentucky
item VIERSTRA, RICHARD - University Of Wisconsin
item HUQ, ENAMUL - University Of Texas At Austin
item DOWNIE, A - University Of Kentucky

Submitted to: Proceedings of the National Academy of Sciences (PNAS)
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/15/2018
Publication Date: 4/9/2018
Citation: Majee, M., Kumar, S., Kathare, P.K., Wu, S., Gingerich, D., Nayak, N.R., Salaita, L., Dinkins, R.D., Martin, K., Goodin, M., Dirk, L.M., Lloyd, T.D., Zhu, L., Chappell, J., Hunt, A.G., Vierstra, R., Huq, E., Downie, A.B. 2018. KELCH F-BOX protein positively influences Arabidopsis seed germination by targeting PHYTOCHROME-INTERACTING FACTOR1. Proceedings of the National Academy of Sciences. www.pnas.org/cgi/doi/10.1073/pnas.1711919115.

Interpretive Summary: Seed germination is a critical control point in plant development and plants have developed sensory systems that assess various environmental cues over time to maximize the successful transition from embryo to seedling. We demonstrate that the Arabidopsis F-Box protein Cold Temperature-Germinating (CTG)-10 is a positive regulator during germination by interacting with proteins involved in the negative regulation of seed germination, thus promoting seed germination and leading to subsequent seedling development. Information from this research will be valuable to plant geneticists and see companies in developing new genetic lines and varieties with improved see germination and development.

Technical Abstract: Seeds employ sensory systems that assess various environmental cues over time to maximize the successful transition from embryo to seedling. Here, we show that the Arabidopsis F-Box protein Cold Temperature-Germinating (CTG)-10, identified by activation tagging, is a positive regulator during this process. When overexpressed, CTG10 hastens aspects of seed germination. CTG10 is expressed predominately in the hypocotyl, the protein from which is localized to the nucleus, interacts with Arabidopsis SKP-Like proteins to presumably generate a SCF E3 complex active in ubiquitination. CTG10 also interacts with Phytochrome Interacting Factor 1 (PIF1) and appears to help regulate its abundance in planta. Both CTG10 and PIF1 amounts decline during seed germination in the light and re-accumulate in the dark. Whereas overexpression of CTG10 accelerates loss of PIF1 in light, increasing germination efficiency, PIF1 overexpression lines fail to complete germination in darkness by a process reversed by concurrent CTG10 overexpression. PIF1 in turn downregulates CTG10 transcription, suggesting a feedback loop of CTG10/PIF1 control. Taken together, we propose that PIF1 and CTG10 co-exist in the nucleus in darkness, but following illumination CTG10 assists in reducing PIF1 amounts, thus promoting the completion of seed germination and subsequent seedling development.