Rf8-Mediated T-urf13Transcript Accumulation Coincides with a Pentatricopeptide Repeat Cluster on Maize Chromosome 2L

Abstract

Cytoplasmic male sterility (CMS) is a maternally inherited inability to produce functional pollen. In Texas (T)-cytoplasm maize (Zea mays L.), CMS results from the action of the URF13 mitochondrial pore-forming protein encoded by the unique T-urf13 mitochondrial gene. Full or partial restoration of fertility to T-cytoplasm maize is mediated by the Rf2a nuclear gene in combination with one of three other genes: Rf1, Rf8, or Rf*. Rf2a encodes a mitochondrial aldehyde dehydrogenase whereas Rf1, Rf8, and Rf* are associated with the accumulation of distinctive T-urf13 mitochondrial transcripts. Rf8-associated RNA processing activity was mapped to a 4.55-Mbp region on chromosome 2L that contains 10 pentatricopeptide repeat (PPR) encoding genes in the B73 5b.60 genome assembly. Genetic linkage analysis also indicated that Rf* is positioned within this PPR cluster as well as Rf3, which restores USDA (S)-cytoplasm maize. Partially male-fertile plants segregated for the presence or absence of the Rf8-associated T-urf13 1.42-and 0.42-kbp transcripts, indicating that the RNA processing event associated with these transcripts is not necessary for anther exsertion. In addition, a statistically signifi cant delay in fl owering was observed between partially male-fertile and mostly male-fertile plants. Taken together, these new results indicate that Rf8-mediated male fertility is under the control of more than one nuclear locus.

Genome-wide analysis of the pentatricopeptide repeat gene family in different maize genomes and its important role in kernel development

“…The PPR gene family in land plants is very large; for example, 441 members are present in Arabidopsis , 477 in rice and 486 in foxtail millet [2–4]. A majority of PPR genes have been confirmed to have functions in plant growth and development, and these genes can affect cytoplasmic male sterility [5–7], embryogenesis [8, 9], and seed development [10–13].…”

Genome-wide analysis of Rf-PPR-like (RFL) genes and a new InDel marker development for Rf1 gene in cytoplasmic male sterile CMS-D2 Upland cotton

“…Additionally, the Rf5 gene in rice was mapped to a 200-kb region on chromosome 8 that contains three RFL genes, one of which, Os08g01870, was located within 15 kb of the marker and cosegregated with the Rf gene (Hu et al 2012;Huang et al 2016). In maize, the Rf8 locus was mapped to an RFL cluster on chromosome 2 (Meyer et al 2011). The only PPR-Rf gene identified in sorghum was found to be located outside of the RFL-rich regions, however, occurs on chromosome 8.…”

Interspecific amphiploid‐derived alloplasmic male sterility with defective anthers, narrow disc florets and small ray flowers in sunflower

“…Partially restored male-fertility was also observed in Brassica (Yasumoto et al 2009), pepper (Lee et al 2008) and CMS-T maize (Meyer et al 2011).…”

“…Additionally, the existence of MF-plants suggests the fertility modifier/partial fertility restorers may be related to anther dehiscence (Zhou et al 2011). Environmental factors also may reduce male-fertility (Yasumoto et al 2009, Meyer et al 2011.…”