Periodic Reporting for period 1 - TRANSLIGHT (Light-dependent composition of transcriptional complexes in plants)
Período documentado: 2019-09-16 hasta 2021-09-15
Due to their sessile nature, plants have evolved very sophisticated mechanisms to respond to changes in environmental conditions. Light and temperature are among the most important environmental inputs, which trigger changes in the expression on hundreds of genes. The signalling pathways that transduce the light and temperature signals in plants have been investigated for many years and several components, and their mechanism of action, are known. However, whether these inputs directly impinge on the transcriptional machinery to modulate gene expression is not known. This project aims to answer this question by studying the effect of light on the activity and accumulation of the RNA polymerase II (RNAPII), and by identifying proteins involved in different moments of the transcription cycle during the response to light. This is an important question that will allow researchers to gain knowledge on how plants adapt to different light regimes, which has a huge impact on plant biology. Moreover, findings from this project could be employed for biotechnological uses in order to improve crop performance.
Plants have evolved very sophisticated mechanisms to respond to changes in the environment where they grow. Light is one of the most important environmental inputs since it is the source of energy for plants to produce sugars. In this project we have tested the ability to respond to light of a cell line derived from the model plant Arabidopsis. Whole Arabidopsis seedlings grown in the dark show a very fast response to light, which is characterized by the greening of their organs. We found that the Arabidopsis cell line does become green in response to a shift from dark to light. However, the response is much slower compared to whole seedlings, suggesting that communications between cells and different organs is important for a proper response to light. Also, we have characterized the accumulation and phosphorylation status of the NRPB1 protein upon different light and temperature regimes. This protein is the catalytic subunit of the RNA polymerase II complex, which involved in transcription of messenger RNAs, and therefore plays a key role in the proper expression of genes. While NRPB1 accumulation and phosphorylation seems stable in most growth conditions, we observed an increase in its accumulation upon high temperature, suggesting that a mechanisms operates to promote NRPB1 accumulation, and perhaps activity, under this temperature regime. Last we have performed some immunoprecipitation experiments where NRPB1 protein has been isolated in order to characterize its protein interactors under different growth conditions, with the final goal of answering whether the composition of the RNA polymerase II complex changes in different light and temperature conditions.
During this period of time, we have attended the SEB-INDEPTH meeting in El Escorial, Spain, where we had the chance to discuss the project with experts in the filed.
During this period of time, we have attended the SEB-INDEPTH meeting in El Escorial, Spain, where we had the chance to discuss the project with experts in the filed.
This project poses an interesting and novel question about the direct impact of light in the composition and activity of the RNAPII machinery. The identification of stage-specific RNAPII interactors in different light conditions is an important experiment that will allow us to better understand how transcription is regulated in plants in response to light. This is critical since light has a pervasive effect on plant biology. This project has allowed the ER to gain knowledge and new skills such as the manipulation of plant cell lines. Moreover, it has allowed the collaboration with the Butter lab, which will be very helpful for this and future projects. In terms of leadership, the ER has been involved in the supervision of a Master´s student –Juan Ignacio Pereyra- who might eventually join the lab as a graduate student under the supervision of the ER. Moreover, during this period, the ER has had the opportunity to present his postdoc work in a training course organized by the VIB in Leuven (Belgium), a meeting organized by the Society for Experimental Biology about chromatin in plants in Madrid (Spain), as well as seminars at the IBMCP and I2sysbIO, both located in Valencia (Spain). During these meetings and seminars, the ER had the chance to meet people and discuss about the TRANSLIGHT project. This has been beneficial to strengthen the ER´s network, and possibly to start new collaborations. Importantly, during this period, the ER has been awarded a Ramón y Cajal contract. This is the equivalent in Spain to the tenure track system. In this regard, the ER has been awarded with a three-year grant from the Spanish Ministry of Science and Innovation that will allow him to hire people and establish his own lab at the IBMCP.