RT Conference Proceedings
T1 NTMC2T5 proteins as lipid bridges between plastids and ER during cotyledon development.
A1 Huércano Rubens, Carolina
A1 Moya-Barrientos, Miriam
A1 Cuevas Corral, Oliver
A1 Salas, Joaquín
A1 Sánchez-Vera, Victoria
A1 Ruiz-López, Noemí
K1 Plantas - Células y tejidos
K1 Cloroplastos
AB The conversion of proplastids to etioplasts is a critical process during seed germination, being essential for the development of cotyledons and the plant itself. Etioplasts play a crucial role in these initial stages as they serve as precursors to chloroplasts. The shift from one type of plastid to another involves massive structural changes. Among these, a key step is the formation of all chloroplastic membranes, which requires the synthesis and delivery of lipids to the plastids. Galactolipids are the most prevalent lipids found in chloroplasts. Notably, during the initial phases of photomorphogenesis, there is a noticeable build up of galactolipids within the plastid membranes, originated from the endoplasmic reticulum (ER). Since vesicular transport between these organelles has not been documented, lipid transport may be mediated by lipid transport proteins (LTP) at membrane contact sites (MCS). LTPs are characterized by unique lipid transport domains, such as the synaptotagmin-like mitochondrial lipid-binding (SMP) domain. However, no specific LTP has been identified as responsible for lipid exchange between the endoplasmic reticulum (ER) and chloroplasts.In our studies, we have identified the NTMC2T5 proteins, as putative lipid chloroplast transfer proteins, as they contain a SMP domain. Our confocal microscopy experiments have demonstrated that these proteins are anchored to the outer envelope membrane of the chloroplast, and BiFC analysis we shown that they interact with the ER, forming ER-Chloroplast MCS. QRT-PCR analysis have revealed that N. benthamiana NTMC2T5 gene is mainly expressed in early stages of seedling development. Further analysis in Nicotiana benthamiana CRISPR/Cas9 knock-out mutants showed (1) delayed greening in cotyledons when germinated in light, (2) an albino-like phenotype when germinated in darkness, (3) clear defect in plastid morphogenesis by transmission electron microscopy and (4) lower content of galactolipids.
YR 2024
FD 2024
LK https://hdl.handle.net/10630/31692
UL https://hdl.handle.net/10630/31692
LA eng
NO Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech.
DS RIUMA. Repositorio Institucional de la Universidad de Málaga
RD 19 ene 2026