Abstract: Monocot plants heterozygous for centromeric histone 3 (CenH3) and optionally expressing gene editing constructs, for use in inducing haploids of a monocot target plant and optionally pass-through gene editing are provided. The monocot haploid inducer plants are typically composed of diploid plant cells having only one allele encoding a functional CENH3 protein. The diploid plant cells can also include, for example, one CenH3 allele encoding non-functional CENH3 protein. In some embodiments, the allele encoding non-functional CENH3 protein is a frameshift mutation, protein null allele, an RNA null allele, or a combination thereof. The monocot haploid inducer plant can also include gene editing machinery, such as a site-directed nuclease and optionally a guide RNA stably expressed by cells of the monocot plant. Methods of inducing formation of a target haploid monocot plant while optionally simultaneously modifying the target monocot plant’s genome are also provided.

Abstract: An engineered centromere, and systems and methods of using the engineered centromere are described. The engineered centromere can have tandem repeats of a DNA sequence with binding motifs to permit binding of fusion proteins that include a DNA binding protein and a kinetochore protein to activate the engineered centromere. Also described are a plant artificial chromosome that includes the engineered centromere, a transgenic plant containing the engineered chromosome, and a method of synthesizing a large molecule by adding multiple genes using the plant artificial chromosome.