20.500.12556/DiRROS-19710 1-aminocyclopropane-1-carboxylate oxidase induction in tomato flower pedicel phloem and abscission related processes are differentially sensitive to ethylene Ethylene has impact on several physiological plant processes, including abscission, during which plants shed both their vegetative and reproductive organs. Cell separation and programmed cell death are involved in abscission, and these have also been correlated with ethylene action. However, the detailed spatiotemporal pattern of the molecular events during abscission remains unknown. We examined the expression of two tomato ACO genes, LeACO1, and LeACO4 that encode the last enzyme in ethylene biosynthesis, 1-aminocyclopropane-1-carboxylate oxidase (ACO), together with the expression of other abscission-associated genes involved in cell separation and programmed cell death, during a period of 0–12 h after abscission induction in the tomato flower pedicel abscission zone and nearby tissues. In addition, we determined their localization in specific cell layers of the flower pedicel abscission zone and nearby tissues obtained by laser microdissection before and 8 h after abscission induction. The expression of both ACO genes was localized to the vascular tissues in the pedicel. While LeACO4 was more uniformly expressed in all examined cell layers, the main expression site of LeACO1 was in cell layers just outside the abscission zone in its proximal and distal part. We showed that after abscission induction, ACO1 protein was synthesized in phloem companion cells, in which it was localized mainly in the cytoplasm. Samples were additionally treated with 1-methylcyclopropene (1-MCP), a competitive inhibitor of ethylene actions, and analyzed 8 h after abscission induction. Cell-layer-specific changes in gene expression were observed together with the specific localization and ethylene sensitivity of the hallmarks of cell separation and programmed cell death. While treatment with 1-MCP prevented separation of cells through inhibition of the expression of polygalacturonases, which are the key enzymes involved in degradation of the middle lamella, this had less impact on the occurrence of different kinds of membrane vesicles and abscission-related programmed cell death. In the flower pedicel abscission zone, the physical progressions of cell separation and programmed cell death are perpendicular to each other and start in the vascular tissues. abscission ACO cell separation ethylene laser microdissection programmed cell death tomato ultrastructure true false true Angleški jezik Ni določen Neznano 2024-07-24 03:46:39 2024-07-24 15:19:46 2024-07-25 04:14:56 0000-00-00 00:00:00 2017 0 0 Nasl. z nasl. zaslona; Opis vira z dne 17. 3. 2017; str. 1-14 Vol. 8 2017 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 2017-03-31 577 1664-462X 10.3389/fpls.2017.00464 4268879 RAZ_Chersicola_Marko_2017.pdf RAZ_Chersicola_Marko_2017.pdf 1 AA5EF0B7DC73838FC8190E64FD9B7595 fb54b8c9aba14915bd9cfb36a4f133b54c661b8f759af88529d445e3520a0738 f78caff7-49ae-11ef-b487-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=27382 https://doi.org/10.3389/fpls.2017.00464 0 0916325e-49af-11ef-b487-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=27384 Nacionalni inštitut za biologijo 0 0 0