Molecular Geneticist with USDA-ARS, Assistant Professor (Adjunct) of Crop and Soil Sciences. Ph.D.1996, University of Chicago.
Seed dormancy and germination are controlled by a complex web of plant hormone interactions. While GA stimulates germination, abscisic acid (ABA) inhibits germination and is required for establishment of seed dormancy. We recently found that brassinosteroid (BR) is also needed to stimulate germination. Our research objectives are to
1) identify genes involved in GA signal transduction
2) test the hypothesis that the F-box gene SLEEPY1 of Arabidopsis transmits the GA signal by directing degradation of the RGA/GAI family of transcription factors
3) elucidate the interactions between the plant hormone signaling pathways controlling germination and
4) apply the knowledge gained to controlling preharvest sprouting in wheat.
Ariizumi, T., Hauvermale, A.L., Nelson, S.K., Hanada, A., Yamaguchi, S., Steber, C.M. 2013. Lifting DELLA repression of seed germination through proteolytic and non-proyteolytic GA signaling. Plant Physiology 162:2125-2139.
Schramm, E.C. Nelson, S.K., Kidwell, K.K., Steber, C.M. 2012. Increased ABA sensitivity results in higher seed dormancy in soft white spring wheat cultivar ‘Zak’. Theoretical and Applied Genetics. 126(3):791-803.
Hauvermale, A.L., Ariizumi, T., Steber, C.M. 2012. Gibberellin signaling: a theme and variations on DELLA repression. Plant Physiology. 160:83-92.
Schramm, E., Nelson, S.K., Steber, C.M. 2012. Wheat ABA-insensitive mutants results in reduced grain dormancy. Euphytica. 188(1),35-49.
Nirmala, J., Drader, T., Lawrence, P.K., Yin, C. Hulbert, S., Steber, C.M., Steffenson, B.J., Szabo, L.J., Von Wettstein, D., Kleinhofs, A. 2011. Concerted action of two avirulent spore effectors activates Reaction to Puccinia graminis 1 (Rpg1)-mediated cereal stem rust resistance. Proceedings of the National Academy of Sciences. 108(35):14676-81.
Ariizumi, T., Steber, C. M. 2011. Mutations in the F-box gene SNEEZY result in decreased arabidopsis GA signaling. Plant Signaling and Behavior. 6(6):831-833.
Schramm, E.C., Abellera, J.C., Strader, L., Garland Campbell, K.A., Steber, C.M. 2010. Isolation of ABA-responsive mutants in allohexaploid bread wheat (Triticum aestivum L.): Drawing connections to grain dormancy, preharvest sprouting, and drought tolerance. Plant Science. 179:620-629.
Abellera, J.C., Strader, L.C., Schramm, E., Garland Campbell, K.A., Steber, C.M. 2010. Isolation of ABA hypersensitive mutants in allhexaploid breadwheat. Genetics.
Okubara, P.A., Steber, C.M., Demacon, V.L., Walter, N., Paulitz, T.C., Kidwell, K.K., EMS-treated hexaploid wheat genotype Scarlet has enhanced tolerance to the soilborne necrotrophic pathogens Rhizoctonia solani AG-8 and R. oryzae. 2009. Theor. Appl. Genet. 119 (February):293-303. Theoretical and Applied Genetics.