@article{fdi:010079940,
  title = {{A} plant-specific {TGS}1 homolog influences gametophyte development in sexual tetraploid {P}aspalum notatum ovules},
  author = {{C}olono, {C}. and {O}rtiz, {J}. {P}. {A}. and {P}ermingeat, {H}. {R}. and {C}anada, {E}. {D}. {S}. and {S}iena, {L}. {A}. and {S}poto, {N}. and {G}aldeano, {F}. and {E}spinoza, {F}. and {L}eblanc, {O}livier and {P}essino, {S}. {C}.},
  editor = {},
  language = {{ENG}},
  abstract = {{A}posporous apomictic plants form clonal maternal seeds by inducing the emergence of non-reduced (2n) embryo sacs in the ovule nucellus and the development of embryos by parthenogenesis. {I}n previous work, we reported a plant-specific {TRIMETHYLGUANOSINE} {SYNTHASE} 1 ({TGS}1) gene ({PN}_{TGS}1-like) showing expression levels positively correlated with sexuality rates in facultative apomictic {P}aspalum notatum. {PN}_{TGS}1-like displayed contrasting in situ hybridization patterns in apomictic and sexual plant ovules from premeiosis to anthesis. {H}ere we transformed sexual {P}. notatum with a {TGS}1-like antisense construction under a constitutive promoter, in order to produce lines with reduced transcript representation. {A}ntisense plants developed prominent trichomes on the adaxial leaf surface, a trait absent from control genotypes. {R}eproductive development analysis revealed occasional formation of twin ovules. {W}hile control individuals typically displayed a single meiotic embryo sac per ovule, antisense lines showed 12.93-15.79% of ovules bearing extra nuclei, which can be assigned to aposporous-like embryo sacs ({AES}-like) or, alternatively, to gametophytes with a misguided cell fate development. {M}oreover, around 8.42-9.52% of ovules showed what looked like a combination of meiotic and aposporous-like sacs. {B}esides, 32.5% of ovules at early developmental stages displayed nucellar cells with prominent nuclei resembling apospory initials ({AI}s), which surrounded the megaspore mother cell ({MMC}) or the {MMC}-derived meiotic products. {T}wo or more concurrent meiosis events were never detected, which suggest a non-reduced nature for the extra nuclei observed in the mature ovules, unless they were generated by proliferation and misguided differentiation of the legitimate meiotic products. {T}he antisense lines produced a similar amount of viable even-sized pollen with respect to control genotypes, and formed an equivalent full seed set (similar to 9% of total seeds) after self-pollination. {F}low cytometry analyses of caryopses derived from antisense lines revealed that all full seeds had originated from meiotic embryo sacs (i.e. by sexuality). {A} reduction of 25.55% in the germination percentage was detected when comparing antisense lines with controls. {O}ur results indicate that {PN}_{TGS}1-like influences ovule, gametophyte and possibly embryo development.},
  keywords = {apomixis ; apospory ; methyltransferase ; plant reproduction ; {TGS}1},
  booktitle = {},
  journal = {{F}rontiers in {P}lant {S}cience},
  volume = {10},
  numero = {},
  pages = {1566 [14p.]},
  ISSN = {1664-462{X}},
  year = {2019},
  DOI = {10.3389/fpls.2019.01566},
  URL = {https://www.documentation.ird.fr/hor/fdi:010079940},
}