info:eu-repo/semantics/article
A plant-specific TGS1 homolog influences gametophyte development in sexual tetraploid Paspalum notatum ovules
Fecha
2019-11Registro en:
Colono, Carolina Marta; Ortiz, Juan Pablo Amelio; Permingeat, Hugo Raúl; Souza Canada, Eduardo Daniel; Siena, Lorena Adelina; et al.; A plant-specific TGS1 homolog influences gametophyte development in sexual tetraploid Paspalum notatum ovules; Frontiers Media; Frontiers in Plant Science; 10; 11-2019; 1-14
1664-462X
CONICET Digital
CONICET
Autor
Colono, Carolina Marta
Ortiz, Juan Pablo Amelio
Permingeat, Hugo Raúl
Souza Canada, Eduardo Daniel
Siena, Lorena Adelina
Spoto, Nicolás Leandro
Galdeano, Florencia
Espinoza, Francisco
Leblanc, Olivier
Pessino, Silvina Claudia
Resumen
Aposporous apomictic plants form clonal maternal seeds by inducing the emergence of non-reduced (2n) embryo sacs in the ovulenucellus and the development of embryos by parthenogenesis. In previous work, we reported a plant-specific TRIMETHYLGUANOSINESYNTHASE 1 (TGS1) gene (PN_TGS1-like) showing expression levels positively correlated with sexuality rates in facultative apomicticPaspalum notatum. PN_ TGS1-like displayed contrasting in situ hybridization patterns in apomictic and sexual plant ovules frompremeiosis to anthesis. Here we transformed sexual Paspalum notatum with a TGS1-like antisense construction under aconstitutive promoter, in order to produce lines with reduced transcript representation. Antisense plants developed prominenttrichomes on the adaxial leaf surface, a trait absent from control genotypes. Reproductive development analysis revealedoccasional formation of twin ovules. While control individuals typically displayed a single meiotic embryo sac per ovule, antisenselines 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. Moreover, around 8.42-9.52% of ovules showed what lookedlike a combination of meiotic and aposporous-like sacs. Besides, 32.5% of ovules at early developmental stages displayed nucellarcells with prominent nuclei resembling apospory initials (AIs), which surrounded the megaspore mother cell (MMC) or theMMC-derived meiotic products. Two or more concurrent meiosis events were never detected, which suggest a non-reduced naturefor the extra nuclei observed in the mature ovules, unless they were generated by proliferation and misguided differentiation ofthe legitimate meiotic products. The antisense lines produced a similar amount of viable even-sized pollen with respect to controlgenotypes, and formed an equivalent full seed set (~9% of total seeds) after self-pollination. Flow cytometry analyses of caryopsesderived from antisense lines revealed that all full seeds had originated from meiotic embryo sacs (i.e. by sexuality). A reduction of25.55 % in the germination percentage was detected when comparing antisense lines with controls. Our results indicate that PN_TGS1-like influences ovule, gametophyte and possibly embryo development.