Identification of IPT9 in Brachiaria brizantha (syn. Urochloa brizantha) and expression analyses during ovule development in sexual and apomictic plants.

Autor: Ferreira LG; Department of Biology, University of Brasília - UnB, Campus Darcy Ribeiro S/N - Asa Norte, Brasília, DF, 70.910-900, Brazil.; Embrapa Genetic Resources and Biotechnology, Parque Estação Biológica, PqEB Av. W5 Norte., Caixa Postal 02372, Brasília, DF, 70.770-917, Brazil., Dusi DMA; Embrapa Genetic Resources and Biotechnology, Parque Estação Biológica, PqEB Av. W5 Norte., Caixa Postal 02372, Brasília, DF, 70.770-917, Brazil., Irsigler AST; Embrapa Genetic Resources and Biotechnology, Parque Estação Biológica, PqEB Av. W5 Norte., Caixa Postal 02372, Brasília, DF, 70.770-917, Brazil., Gomes ACMM; Embrapa Genetic Resources and Biotechnology, Parque Estação Biológica, PqEB Av. W5 Norte., Caixa Postal 02372, Brasília, DF, 70.770-917, Brazil., Florentino LH; Embrapa Genetic Resources and Biotechnology, Parque Estação Biológica, PqEB Av. W5 Norte., Caixa Postal 02372, Brasília, DF, 70.770-917, Brazil., Mendes MA; Dipartimento di Bioscienze, Università degli Studi di Milano, Via Celoria 26, 20133, Milan, Italy. Marta.Mendes@unimi.it., Colombo L; Dipartimento di Bioscienze, Università degli Studi di Milano, Via Celoria 26, 20133, Milan, Italy., Carneiro VTC; Department of Biology, University of Brasília - UnB, Campus Darcy Ribeiro S/N - Asa Norte, Brasília, DF, 70.910-900, Brazil. vera.carneiro@embrapa.br.; Embrapa Genetic Resources and Biotechnology, Parque Estação Biológica, PqEB Av. W5 Norte., Caixa Postal 02372, Brasília, DF, 70.770-917, Brazil. vera.carneiro@embrapa.br.
Jazyk: angličtina
Zdroj: Molecular biology reports [Mol Biol Rep] 2023 Jun; Vol. 50 (6), pp. 4887-4897. Date of Electronic Publication: 2023 Apr 18.
DOI: 10.1007/s11033-023-08295-7
Abstrakt: Background: In Brachiaria sexual reproduction, during ovule development, a nucellar cell differentiates into a megaspore mother cell (MMC) that, through meiosis and mitosis, gives rise to a reduced embryo sac. In aposporic apomictic Brachiaria, next to the MMC, other nucellar cells differentiate into aposporic initials that enter mitosis directly forming an unreduced embryo sac. The IPT (isopentenyltransferase) family comprises key genes in the cytokinin (CK) pathway which are expressed in Arabidopsis during ovule development. BbrizIPT9, a B. brizantha (syn. Urochloa brizantha) IPT9 gene, highly similar to genes of other Poaceae plants, also shows similarity with Arabidopsis IPT9, AtIPT9. In this work, we aimed to investigate association of BbrizIPT9 with ovule development in sexual and apomictic plants.
Methods and Results: RT-qPCR showed higher BbrizIPT9 expression in the ovaries of sexual than in the apomictic B. brizantha. Results of in-situ hybridization showed strong signal of BbrizIPT9 in the MMC of both plants, at the onset of megasporogenesis. By analyzing AtIPT9 knockdown mutants, we verified enlarged nucellar cell, next to the MMC, in a percentage significantly higher than in the wild type, suggesting that knockout of AtIPT9 gene triggered the differentiation of extra MMC-like cells.
Conclusions: Our results indicate that AtIPT9 might be involved in the proper differentiation of a single MMC during ovule development. The expression of a BbrizIPT9, localized in male and female sporocytes, and lower in apomicts than in sexuals, and effect of IPT9 knockout in Arabidopsis, suggest involvement of IPT9 in early ovule development.
(© 2023. The Author(s).)
Databáze: MEDLINE
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