AUTHOR=Kelliher Timothy , Starr Dakota , Wang Wenling , McCuiston Jamie , Zhong Heng , Nuccio Michael L. , Martin Barry 

TITLE=Maternal Haploids Are Preferentially Induced by CENH3-tailswap Transgenic Complementation in Maize

JOURNAL=Frontiers in Plant Science

VOLUME=7

YEAR=2016

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2016.00414

DOI=10.3389/fpls.2016.00414

ISSN=1664-462X

ABSTRACT=<p>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, <italic>CENH3</italic><sup>−∕−</sup> and <italic>CENH3:RNAi</italic> lines were complemented by <italic>AcGREEN-tailswap-CENH3</italic> or <italic>AcGREEN-CENH3</italic> 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. <italic>CENH3</italic>:<italic>RNAi</italic> lines did not demonstrate consistent knockdown and rarely produced haploids. In contrast, many of the complemented <italic>CENH3</italic><sup>−∕−</sup> 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 <italic>CENH3</italic>-<italic>tailswap</italic> transgenes can be used to engineer <italic>in vivo</italic> haploid induction systems into maize plants.</p>