Math Bio Colloquium on Thursday at 3:30 in MG2090

Dr. Janick-Buckner will be the speaker at the next mathbio colloquium.

Abstract: Characterization of a New ROUGH SHEATH1 Mutant of Maize (Development & Cell Biology)
Graves, M. Christine1; Tracy, Christopher1; Khidir, Hazar1; Scanlon, Michael2; Buckner, Brent1; Janick-Buckner, Diane1
1 Truman State University, Kirksville, MO, 63501
2 Cornell University, Ithaca, NY, 14853

In maize, class 1 knox genes are expressed in the shoot apical meristem and encode transcription factors that are involved in cell fate decisions. A knox-like mutant was identified in a maize line that exhibits active Mutator transposition. This knox-like phenotype is evident as aberrant cell patterning at the leaf sheath/blade boundary and develops on more developmentally mature plants. SSR mapping indicates that the gene responsible for this mutant phenotype is closely linked to rough sheath1 (rs1), a class 1 knox gene. In addition, a Mu-TIR/rs1 PCR primer pair consistently amplified DNA in mutant plants. RT-PCR was used to qualitatively characterize the expression of eight class 1 knox genes in leaf tissues. rs1, lg3, knox5, knox8 and knox11 were all ectopically expressed in the mutant sheath/blade boundary; rs1 was also ectopically expressed in mutant blade tissue. Preliminary histological analysis of this Mu-tagged rs1 mutant indicates that there may be an expansion of sclerenchyma cells in sheath/blade boundary and that there is less lignin found in this region compared to wild-type plants. We also observed that these Mu-tagged rs1 plants have abundant lesions on their leaf blades, which appears to be suppressed when plants also bear a Mu-tagged WRKY1 allele. Current studies continue to investigate the histological and lignin content of plants segregating for Mu-tagged rs1 and/or Mu-tagged WKRY1 alleles.

Funding acknowledgement: National Science Foundation (NSF)