title: Maternal Haploids Are Preferentially Induced by CENH3-tailswap Transgenic Complementation in Maize.
abstract: Doubled haploid plants are invaluable breeding tools but many crop species are recalcitrant to available haploid induction techniques. To test if haploid inducer lines can be engineered into crops, CENH3 (-∕-) and CENH3:RNAi lines were complemented by AcGREEN-tailswap-CENH3 or AcGREEN-CENH3 transgenes. Haploid induction rates were determined following testcrosses to wild-type plants after independently controlling for inducer parent sex and transgene zygosity. CENH3 fusion proteins were localized to centromeres and did not cause vegetative defects or male sterility. CENH3:RNAi lines did not demonstrate consistent knockdown and rarely produced haploids. In contrast, many of the complemented CENH3 (-∕-) lines produced haploids at low frequencies. The rate of gynogenic haploid induction reached a maximum of 3.6% in several hemizygous individuals when backcrossed as males. These results demonstrate that CENH3-tailswap transgenes can be used to engineer in vivo haploid induction systems into maize plants.
authors.affiliation: Biology Research, Syngenta Crop Protection, Research Triangle Park Durham, NC, USA.
authors.forename: Timothy
authors.initials: T
authors.lastname: Kelliher
authors.affiliation: Biology Research, Syngenta Crop Protection, Research Triangle Park Durham, NC, USA.
authors.forename: Dakota
authors.initials: D
authors.lastname: Starr
authors.affiliation: Biology Research, Syngenta Crop Protection, Research Triangle Park Durham, NC, USA.
authors.forename: Wenling
authors.initials: W
authors.lastname: Wang
authors.affiliation: Biology Research, Syngenta Crop Protection, Research Triangle Park Durham, NC, USA.
authors.forename: Jamie
authors.initials: J
authors.lastname: McCuiston
authors.affiliation: Biology Research, Syngenta Crop Protection, Research Triangle Park Durham, NC, USA.
authors.forename: Heng
authors.initials: H
authors.lastname: Zhong
authors.affiliation: Biology Research, Syngenta Crop Protection, Research Triangle Park Durham, NC, USA.
authors.forename: Michael L
authors.initials: ML
authors.lastname: Nuccio
authors.affiliation: Biology Research, Syngenta Crop Protection, Research Triangle Park Durham, NC, USA.
authors.forename: Barry
authors.initials: B
authors.lastname: Martin
keywords: CENH3; RNA interference; centromeres; doubled haploids; genome elimination; haploid induction; mutant complementation