NSF-IOB: Plant-Microbe Interactions, Genetic and Molecular Insights Into Mechanisms Underlying a Maize Disease

The major objective of this proposal is to elucidate how HC-toxin, a determinant of disease caused by race 1 of Cochliobolus carbonum, facilitates maize pathogenesis. This is being accomplished by a combination of genetic and genomics approaches. While the genetic approach focuses on maize mutants that no longer succumb to infection by C. carbonum, the genomics approach is based on RNA profiling to identify genes whose expression is specifically impacted by HC-toxin. Additional objectives are to examine the developmental behavior and evolutionary origin of host genes that confer resistance to this pathogen.

Three publications resulting from this award [1-3] are indicated with an asterisk in the References Cited section).

NSF-MCB The Genetics of Genetics: Genes controlling meiotic recombination in maize. (subawards to H. Dooner, Waksman Institute, W. Eggleston, Va. Commonwealth Univ., P. Schnable, Iowa St. Univ. and S. Stack, Colorado St. Univ.; on no-cost extension).

The major objective of this project has been to identify mutants that have altered rates and localizations of meiotic recombination events using marker alleles causing visible kernel phenotypes. We have succeeded in finding ~60 putative mutations, have thus far validated 10 of these (more are in progress) and are initiating mapping of these mutations. Once homozygous rec lines are established we will begin characterizing the placement and number of recombination nodules in these lines, whether their effects are global or restricted to specific regions of the genome and whether they influence the positioning of transposition events.

NSF-DBI The Maize TILLING Project

The objective of this project is to establish the Maize TILLING Project (MTP) a TILLING service for the maize community and those researching other crop and potential crop plants. This award followed an initial award to set up the service in conjunction with the Seattle TILLING Project and the second award is to facilitate making additional mutant populations to screen and to move MTP to a full cost-recovery basis. We have provided over 500 alleles in over 130 genes to the community, have initiated additional projects in soybean, marigold, sorghum, switchgrass and berries. In addition we have established a service analyzing natural variation among maize inbreds for genes of interest (EcoTILLING), and this is also being expanded to the additional crops mentioned above. Finally, we are developing targeted resequencing methodologies for use with short-read, next generation, massively parallel sequencers (Illumina/Solexa and ABI SOLiD) to increase throughput and reduce costs of mutation detection.

Eight publications resulting from these awards [4-11] are indicated with an asterisk in the References Cited section.