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ARS Home » Southeast Area » Tifton, Georgia » Crop Genetics and Breeding Research » Research » Publications at this Location » Publication #335987
Title: The genes BM2 and BLMC that affect epicuticular wax deposition in sorghum are allelic

Author
item PUNNURI, SOMASHEKHAR - Fort Valley State University
item Harris-Shultz, Karen
item Knoll, Joseph - Joe
item Ni, Xinzhi
item Wang, Hongliang

Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/2/2017
Publication Date: 3/9/2017
Citation: Punnuri, S., Harris-Shultz, K.R., Knoll, J.E., Ni, X., Wang, H. 2017. The genes BM2 and BLMC that affect epicuticular wax deposition in sorghum are allelic. Crop Science. 57:1552-1556.

Interpretive Summary: The plant cuticle, with its associated epicuticular and intracuticular waxes, provides a hydrophobic layer that covers the epidermis of all land plants. This layer protects plants from desiccation, external environmental stresses, as well as other organisms. Previous studies identified mutant plants with mutations in the same gene called Bloomless 2 that caused a loss of epicuticular wax as well as a reduction in cuticle deposition. Shortly thereafter a new mutant, blmc, was characterized and mapped onto sorghum Chr. 10. We sought to determine if these genes are allelic. In this study populations were made and the resulting plants were assessed in the field for wax. This experiment revealed that blmc is a mutant of the Bloomless 2 locus. Thus, data that had been generated independently for each mutant can be merged and gives more information about the effects of the Bloomless 2 gene. In particular the Bloomless 2 gene is on sorghum Chr. 10 and has many effects such as cuticle synthesis, reduction of leaf water loss, susceptibility to greenbug biotype C, and resistance to the fungal pathogen that causes corn leaf blight.

Technical Abstract: Epicuticular waxes (EW) coat the aerial surfaces of the sorghum (Sorghum bicolor) plant and have a role in the plants’ resistance to abiotic and biotic stresses such as drought, ultraviolet light, insects, and fungal pathogens. Mutants of the Bloomless 2 (BM2) locus, such as bm2-3, lack EW as well as have inhibited synthesis of the cuticle. The sorghum mutant bloom-cuticle (blmc), also lacks EW, has inhibited synthesis of the cuticle, as well as many other effects. In this study, an allelism test was performed, which revealed that blmc is an allele of the BM2 locus and is hereby named bm2-7. This information allows the data that has been generated separately from each of these mutations to be merged. Thus the BM2 locus is on sorghum Chr. 10 and has many pleiotropic effects including cuticle proper synthesis, reduction of leaf water loss, greenbug biotype C (Schizaphis graminum) susceptibility, and resistance to the fungal pathogen Exserohilum turcicum that causes corn leaf blight.