PARTNERSHIP: CHARACTERIZATION OF CRISPR/CAS9 MUTANTS OF SORGHUM HAVING LESIONS IN THE INHIBITION OF ALIEN POLLEN (IAP) LOCUS

The long-term goal of this research is to develop two types of new sorghum cultivars with different outcrossing abilities: those having a reduced capacity to accept the pollen of close wild relatives (by strengthening the reproductive barrier), and those having an enhanced capacity to accept the "alien" pollen of distant wild relatives (by removing the barrier).With this in mind, the specific goal of this project is to identify the causal genes contained within the INHIBITION OF ALIEN POLLEN (IAP) locus, which is currently the only known reproductive barrier locus (pre- or post-zygotic) in the Sorghum genus. Our previous efforts have identified three candidate genes involved in pistil-expressed cross-incompatibility at the IAP locus, but the strongest candidate (Sobic.002g023300) is not represented in any publicly available mutant libraries. Therefore, we have used CRISPR/Cas9 to generate three iap mutant lines (each having a lesion in one candidate gene) in a common genetic background (Tx430), and we propose to characterize the effects of each mutation on gene expression, plant morphology, and reproductive biology in order to pinpoint the causal allele(s) and ultimately create a set of publicly available plant materials and resources that will enable long-term studies of reproductive biology in the Sorghum crop-wild species complex.