Abstract
BackgroundThe cell cycle and cellular oxidative stress responses are tightly controlled for proper growth and development of Scots pine (Pinus sylvestris L.) seed. Programmed cell death (PCD) is an integral part of the embryogenesis during which megagametophyte cells in the embryo surrounding region (ESR) and cells in the nucellar layers face death. In the present study, we show both the tissue and developmental stage specific expression of the genes encoding the autophagy related ATG5, catalase (CAT), and retinoblastoma related protein (RBR) as well as the connection between the gene expressions and cell death programs.ResultsWe found strong CAT expression in the cells of the developing embryo throughout the embryogenesis as well as in the cells of the megagametophyte and the nucellar layers at the early embryogeny. The CAT expression was found to overlap with both the ATG5 expression and hydrogen peroxide localization. At the late embryogeny, CAT expression diminished in the dying cells of the nucellar layers as well as in megagametophyte cells, showing the first signs of incipient cell death. Accumulation of starch and minor RBR expression were characteristic of megagametophyte cells in the ESR, whereas strong RBR expression was found in the cells of the nucellar layers at the late embryogeny.ConclusionsOur results suggest that ATG5, CAT, and RBR are involved in the Scots pine embryogenesis and cell death processes. CAT seems to protect cells against hydrogen peroxide accumulation and oxidative stress related cell death especially during active metabolism. The opposite expression of RBR in the ESR and nucellar layers alongside morphological characteristics emphasizes the different type of the cell death processes in these tissues. Furthermore, the changes in ATG5 and RBR expressions specifically in the megagametophyte cells dying by necrotic cell death suggest the genetic regulation of developmental necrosis in Scots pine embryogenesis.Electronic supplementary materialThe online version of this article (doi:10.1186/s12870-015-0462-0) contains supplementary material, which is available to authorized users.
Highlights
The cell cycle and cellular oxidative stress responses are tightly controlled for proper growth and development of Scots pine (Pinus sylvestris L.) seed
We focus on the cell death processes in the embryo surrounding region (ESR) and nucellar layers during the Scots pine seed development, and show that ATG5 previously connected to the regulation of vacuolar cell death expresses in the cells destroyed via necrotic-like cell death
Nuclear DNA fragmentation in ESR and nucellar layers In our previous study, we showed that megagametophyte cells in the ESR are destroyed by morphologically necrotic cell death and the cells in the megagametophyte surrounding nucellar layers die during the Scots pine seed development [35]
Summary
The cell cycle and cellular oxidative stress responses are tightly controlled for proper growth and development of Scots pine (Pinus sylvestris L.) seed. We show both the tissue and developmental stage specific expression of the genes encoding the autophagy related ATG5, catalase (CAT), and retinoblastoma related protein (RBR) as well as the connection between the gene expressions and cell death programs. In multicellular organisms such as plants, the organized destruction of cells by programmed cell death (PCD) is essential for body plans and specific organ shapes as well as for removing damaged or infected cells [1,2,3,4]. The direct interaction of CAT with ROS could allow CAT to act as a molecular link between ROS and the promotion of autophagy-dependent cell death [14]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
