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Dynamics of the Light Harvesting Complex network

English title Dynamics of the Light Harvesting Complex network
Applicant Longoni Paolo
Number 179417
Funding scheme Project funding (Div. I-III)
Research institution Institut de Biologie Université de Neuchâtel
Institution of higher education University of Neuchatel - NE
Main discipline Molecular Biology
Start/End 01.09.2018 - 31.12.2022
Approved amount 369'242.00
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All Disciplines (4)

Discipline
Molecular Biology
Biochemistry
Genetics
Botany

Keywords (5)

Light Acclimation; Arabidopsis thaliana; Photosynthesis; Phosphoproteome; Light Harvesting Complex

Lay Summary (Italian)

Lead
La luce è la sorgente primaria di energia per tutti i viventi. L’energia luminosa viene convogliata verso i centri di reazione della fotosintesi grazie a un complesso antenna. Questo complesso è costituito da un sistema di proteine interconnesse capaci di ri-organizzarsi per rispondere rapidamente e dinamicamente ai cambiamenti luminosi. Il progetto si propone di utilizzare degli strumenti biotecnologici per studiare le dinamiche di questo complesso.
Lay summary

Soggetto e Obiettivi

La vitalità di una pianta e la sua resistenza dipendono dalla capacità di ottimizzare l’utilizzo della luce. Questa fonte energetica in natura è incostante; intensità e lunghezza d’onda predominante variano continuamente. Per essere in grado di garantire sempre la migliore efficienza fotosintetica le piante devono poter rapidamente adattare il complesso antenna dedicato alla cattura della luce. Questo complesso è costituito da un network di proteine interconnesse. Una parte definita di queste proteine serve a regolare la connessione tra di loro e coi centri di reazione della fotosintesi determinando quindi la struttura dell’intero network.

Tramite la modificazione mirata di questa porzione regolativa si potrà agire sulla struttura del network proteico per comprendere come questa organizzazione dinamica renda le piante capaci di ottimizzare la fotosintesi in diverse condizioni luminose.

Contesto socio-scientifico

Nel contesto del cambiamento climatico in atto e della crescita della popolazione risulta essenziale trovare dei metodi per incrementare la produttività delle piante anche in condizioni avverse. Una comprensione dettagliata delle capacità di adattamento della fotosintesi ci potrà permettere in futuro di sviluppare strategie mirate per migliorarne le prestazioni.

Direct link to Lay Summary Last update: 12.04.2018

Responsible applicant and co-applicants

Employees

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Associated projects

Number Title Start Funding scheme
146300 Chloroplast signaling and acclimation to changing light 01.04.2013 Project funding (Div. I-III)

Abstract

Efficient use of the light is essential for the fitness of photosynthetic organisms. It is believed that the evolution of an antenna network system, capable of dynamic regulation of the fraction of light energy to be transferred to the photosystems and to dissipate light excess is a key step in the evolution of photosynthetic eukaryotes and a crucial step in land colonization. The core structure of the pigment-protein complexes devoted to light harvesting (LHCs) is largely conserved among eukaryotes. However, the regulatory portions display a certain degree of variability which may underlie their role in specific adaptation to particular climatic conditions. The aim of the proposed research project is to understand the network of interactions between the proteins of the thylakoid membrane that allows coping with the changes in light quality and regime exploiting the model organisms Arabidopsis thaliana. In particular, the project will focus on the contribution of the N-terminal domain of the major light harvesting antenna (LHCII) and its phosphorylation to the regulatory dynamics of the thylakoids. The primary focus will be to understand the contribution of the two major isoforms of the LHCII complex LHCB1 and LHCB2. These being the major components of the trimeric LHCII and dynamically phosphorylated at the N-terminus. At the end of the proposed project the specific role of each isoforms’ N-terminus in vivo for the regulation of photosynthetic electron transfer, the assembly of photosynthetic supercomplexes and the architecture of the thylakoid membrane network will be revealed. The key tool for the investigation will be the production of Arabidopsis lines expressing mutated versions of the major light harvesting complex isoforms. These will be obtained by complementing previously produced knock-out lines with LHCII isoforms containing a modified phosphorylation site. By analyzing their photosynthetic performance and photosystems structure under changing light regimes it will be possible to elucidate the role of their dynamic interaction with other components of the photosynthetic machinery. Furthermore, the results will allow the elaboration of hypotheses on the evolution of this regulation system. Moreover, since antenna re-organization is central in the photosynthetic acclimation responses, the new detailed knowledge should allow informed manipulations of its kinetics. It has already been demonstrated that by reducing the response time it is possible to engineer a higher productivity in the field. Furthermore, understanding these mechanisms will offer new targets for genetic selection in crop breeding programs and provide concepts applicable to the design of artificial-photosynthesis systems.
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