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Roberto Bassi

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I am a plant and environmental biologist studying molecular mechanisms which allowed photosynthetic organsms to conquer land and optimize primary productivity in different environments with particular focus in light harvesting and light use efficiency. Applied aspects of our work include improving crop photosynthetic efficiency and resistance to abiotic stresses. Complementary research focuses on biofuel production to minimize CO2 release in athmosphere and air pollution.

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The University of Sheffield

University of California, San Diego

Animal Health Research Institute

Prof. Tofazzal Islam

Bangabandhu Sheikh Mujibur Rahman Agricultural University

College of Applied Sciences, Oman

Walter Zegada-Lizarazu

University of Tuzla

EMBRAPA - Empresa Brasileira de Pesquisa Agropecuária

Evander Ferreira

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Papers by Roberto Bassi

A Light Harvesting Complex-Like Protein in Maintenance of Photosynthetic Components in <i>Chlamydomonas</i>

Plant Physiology, Jun 21, 2017

Using a genetic approach, we have identified and characterized a novel protein, named Msf1 (Maint... more Using a genetic approach, we have identified and characterized a novel protein, named Msf1 (Maintenance factor for photosystem I), that is required for the maintenance of specific components of the photosynthetic apparatus in the green alga Chlamydomonas reinhardtii. Msf1 belongs to the superfamily of light-harvesting complex proteins with three transmembrane domains and consensus chlorophyll-binding sites. Loss of Msf1 leads to reduced accumulation of photosystem I and chlorophyll-binding proteins/complexes. Msf1is a component of a thylakoid complex containing key enzymes of the tetrapyrrole biosynthetic pathway, thus revealing a possible link between Msf1 and chlorophyll biosynthesis. Protein interaction assays and greening experiments demonstrate that Msf1 interacts with Copper target homolog1 (CHL27B) and accumulates concomitantly with chlorophyll in Chlamydomonas, implying that chlorophyll stabilizes Msf1. Contrary to other light-harvesting complex-like genes, the expression of Msf1 is not stimulated by high-light stress, but its protein level increases significantly under heat shock, iron and copper limitation, as well as in stationary cells. Based on these results, we propose that Msf1 is required for the maintenance of photosystem I and specific protein-chlorophyll complexes especially under certain stress conditions.

Nonphotochemical Quenching of Chlorophyll Fluorescence in <i>Chlamydomonas reinhardtii</i>

Biochemistry, Jan 13, 2006

Unlike plants, Chlamydomonas reinhardtii shows a restricted ability to develop nonphotochemical q... more Unlike plants, Chlamydomonas reinhardtii shows a restricted ability to develop nonphotochemical quenching upon illumination. Most of this limited quenching is due to state transitions instead of ∆pH-driven high-energy state quenching, qE. The latter could only be observed when the ability of the cells to perform photosynthesis was impaired, either by lowering temperature to ∼0 °C or in mutants lacking RubisCO activity. Two main features were identified that account for the low level of qE in Chlamydomonas. On one hand, the electrochemical proton gradient generated upon illumination is apparently not sufficient to promote fluorescence quenching. On the other hand, the capacity to transduce the presence of a ∆pH into a quenching response is also intrinsically decreased in this alga, when compared to plants. The possible mechanism leading to these differences is discussed.

Supramolecular assembly of chloroplast NADH dehydrogenase-like complex with photosystem I from Arabidopsis thaliana

Molecular Plant, 2022

Cyclic electron transport/flow (CET/CEF) in chloroplasts is a regulatory process essential for op... more Cyclic electron transport/flow (CET/CEF) in chloroplasts is a regulatory process essential for optimization of plant photosynthetic efficiency. A crucial CEF pathway is catalyzed by a membrane-embedded NADH dehydrogenase-like (NDH) complex containing at least 29 protein subunits and associating with photosystem I (PSI) to form the NDH-PSI supercomplex. Here we report the 3.9 Å resolution structure of Arabidopsis thaliana NDH-PSI (AtNDH-PSI) supercomplex. We have constructed structural models for 26 AtNDH subunits, among which 11 subunits are unique to chloroplast and stabilize the core part of NDH complex. In the supercomplex, one NDH can bind up to two PSI-light harvesting complex I (PSI-LHCI) complexes at both sides of its membrane arm. Two minor LHCIs, Lhca5 and Lhca6, each present in one PSI-LHCI, interact with NDH and contribute to the supercomplex formation and stabilization. Our results showed structural details of the supercomplex assembly and provide molecular basis for further investigation of the regulatory mechanism of CEF in plants.

Characterization of magnetic nanoparticles functionalized with albumin for biological applications

2009 International Semiconductor Conference, 2009

In this paper we present a method for the large-scale preparation of biodegradable, biocompatible... more In this paper we present a method for the large-scale preparation of biodegradable, biocompatible magnetic nanospheres, intended to be used for cell labeling techniques in magnetic separation of cells. We obtained magnetite nanoparticles functionalized with albumin using an ultrasonic method, at temperatures between 80-95degC. They were tested in a microfluidic channel. The characterization of the the magnetic nanoparticles functionalized with

Analysis of the Chloroplast Protein Kinase Stt7 during State Transitions

Apple Academic Press eBooks, Apr 19, 2016

State transitions allow for the balancing of the light excitation energy between photosystem I an... more State transitions allow for the balancing of the light excitation energy between photosystem I and photosystem II and for optimal photosynthetic activity when photosynthetic organisms are subjected to changing light conditions. This process is regulated by the redox state of the plastoquinone pool through the Stt7/STN7 protein kinase required for phosphorylation of the light-harvesting complex LHCII and for the reversible displacement of the mobile LHCII between the photosystems. We show that Stt7 is associated with photosynthetic complexes including LHCII, photosystem I, and the cytochrome b 6 f complex. Our data reveal that Stt7 acts in catalytic amounts. We also provide evidence that Stt7 contains a transmembrane region that separates its catalytic kinase domain on the stromal side from its N-terminal end in the thylakoid lumen with two conserved Cys that are critical for its activity and state transitions. On the basis of these data, we propose that the activity of Stt7 is regulated through its transmembrane domain and that a disulfide bond between the two lumen Cys is essential for its activity. The high-light-induced reduction of this bond may occur through a transthylakoid thiol-reducing pathway driven by the ferredoxinthioredoxin system which is also required for cytochrome b 6 f assembly and heme biogenesis.

Magnetic Nanoparticles extracted from magnetotactic bacteria as contrast agents for MRI

Magnetic Nanoparticles extracted from magnetotactic bacteria as contrast agents for MRI Pasquina ... more Magnetic Nanoparticles extracted from magnetotactic bacteria as contrast agents for MRI Pasquina Marzola, Leonardo Ghin, Stefano Tambalo, Giamaica Conti, Silvia Mannucci, Alice Busato, Elvira Fantechi, Claudia Innocenti, Claudio Sangregorio, Alessandro Lascialfari, Tomas Orlando, Roberto Bassi, and Andrea Sbarbati Department of Computer Science, University of Verona, Verona, Italy, Department of Biotechnology, University of Verona, Verona, Italy, Department of Neurological and Movement Science, University of Verona, Verona, Italy, INSTM-LaMM, Dept. of Chemistry, University of Florence, Florence, Italy, Department of Physics, University of Milan, Milan, Italy

Dissipative response to excess light is catalyzed in monomeric and trimeric light harvesting complexes by two independent mechanisms

Nature plants, 2016

Oxygenic photoautotrophs require mechanisms for rapidly matching the level of chlorophyll excited... more Oxygenic photoautotrophs require mechanisms for rapidly matching the level of chlorophyll excited states from light harvesting with the rate of electron transport from water to carbon dioxide. These photoprotective reactions prevent formation of reactive excited states and photoinhibition. The fastest response to excess illumination is the so-called nonphotochemical quenching which, in higher plants, requires the luminal pH sensor PsbS and other yet unidentified components of the photosystem II antenna. Both trimeric light-harvesting complex II (LHCII) and monomeric LHC proteins have been indicated as site(s) of the heat-dissipative reactions. Different mechanisms have been proposed: energy transfer to a lutein quencher in trimers, formation of a zeaxanthin radical cation in monomers. Here, we report on the construction of a mutant lacking all monomeric LHC proteins but retaining LHCII trimers. Its non-photochemical quenching induction rate was substantially slower with respect to the wild type. A carotenoid radical cation signal was detected in the wild type, although it was lost in the mutant. We conclude that non-photochemical quenching is catalysed by two independent mechanisms, with the fastest activated response catalysed within monomeric LHC proteins depending on both zeaxanthin and lutein and on the formation of a radical cation. Trimeric LHCII was responsible for the slowly activated quenching component whereas inclusion in supercomplexes was not required. This latter activity does not depend on lutein nor on charge transfer events, whereas zeaxanthin was essential.

A paler shade of green: engineering cellular chlorophyll content to enhance photosynthesis in crowded environments

New Phytologist

SummaryIn natural ecosystems, plants compete for space, nutrients and light. The optically dense ... more SummaryIn natural ecosystems, plants compete for space, nutrients and light. The optically dense canopies limit the penetration of photosynthetically active radiation and light often becomes a growth‐limiting factor for the understory. The reduced availability of photons in the lower leaf layers is also a major constraint for yield potential in canopies of crop monocultures. Traditionally, crop breeding has selected traits related to plant architecture and nutrient assimilation rather than light use efficiency. Leaf optical density is primarily determined by tissue morphology and by the foliar concentration of photosynthetic pigments (chlorophylls and carotenoids). Most pigment molecules are bound to light‐harvesting antenna proteins in the chloroplast thylakoid membranes, where they serve photon capture and excitation energy transfer toward reaction centers of photosystems. Engineering the abundance and composition of antenna proteins has been suggested as a strategy to improve lig...

Equilibrium distribution of excited states in photosystem II antenna

A chimeric hydrolase-PTXD transgene enables chloroplast-based heterologous protein expression and non-sterile cultivation of Chlamydomonas reinhardtii

Algal Research, 2021

Abstract Photosynthetic microalgae hold great potential as light-driven heterologous protein expr... more Abstract Photosynthetic microalgae hold great potential as light-driven heterologous protein expression hosts. In particular, the algal chloroplast is an ideal sub-cellular site for the compartmentalized synthesis and accumulation of high-value recombinant proteins. However, full integration of transplastomic algal biotechnology in the large-scale production of biocatalysts still suffers from major bottlenecks, such as genetic instability and pest contamination. To enhance the reliability of plastid-based algal expression platforms we developed a self-reinforcing genetic system in Chlamydomonas reinhardtii. We transformed the plastome with a bifunctional transgene encoding an in vivo cleavable fusion polypeptide composed of a hyperthermophilic cellulase and the phosphite dehydrogenase PTXD. The dual use of phosphite as a low-cost, environmentally friendly selective agent and fertilizer afforded axenic algal cultivation via mixotrophic metabolism and efficient expression of the hydrolytic enzyme. This study provides an example of chloroplast genetic engineering in which biosafety is integrated in the sustainable management of microalgal monocultures to produce enzymes with industrial applications.

Look for methods, not conclusions

Cell Death & Disease, 2019

ProteinProtein Interactions Induce pH-Dependent and Zeaxanthin-Independent Photoprotection in the Plant Light-Harvesting Complex, LHCII

Algae: A New Biomass Resource

Springer eBooks, Jul 20, 2018

ABSTRACT Definition of the SubjectAlgae are oxygenic photoautotrophs, offering a very high level ... more ABSTRACT Definition of the SubjectAlgae are oxygenic photoautotrophs, offering a very high level of biodiversity and thus suitable for different practical applications. Today, they are mainly cultivated for human/animal food or to extract high-value chemicals and pharmaceuticals. However, their exploitation could be extended. Algae are attractive as high yield biomass producers, because of the short life cycle, the ability to grow up to very high cell densities, and the easy large-scale cultivation that does not compete with other demands such as those of conventional crops agriculture. Algae can be a resource of renewable, sustainable biofuels. In addition, they can be transformed into “cell factories” to produce recombinant proteins of interest for pharmaceutical companies.IntroductionAlgae are described as “lower” plants that never have true stems, roots, and leaves, and grow photoautotrophically by performing oxygenic photos ...

A kaleidoscope of photosynthetic antenna proteins and their emerging roles

Plant Physiology, Apr 21, 2022

Photosynthetic light-harvesting antennae are pigment-binding proteins that perform one of the mos... more Photosynthetic light-harvesting antennae are pigment-binding proteins that perform one of the most fundamental tasks on Earth, capturing light and transferring energy that enables life in our biosphere. Adaptation to different light environments led to the evolution of an astonishing diversity of light-harvesting systems. At the same time, several strategies have been developed to optimize the light energy input into photosynthetic membranes in response to fluctuating conditions. The basic feature of these prompt responses is the dynamic nature of antenna complexes, whose function readily adapts Update

Mapping out Photoprotective Dissipation in Green Plants Using Ultrabroadband 2D Electronic Spectroscopy

The 22nd International Conference on Ultrafast Phenomena 2020, 2020

Carotenoid-Mediated Light Harvesting in Plants Uncovered with Ultrabroadband Two-Dimensional Electronic Spectroscopy

Frontiers in Optics / Laser Science, 2020

We demonstrate an ultrabroadband two-dimensional electronic spectrometer that maps energy flow ac... more

Time-resolved Fluorescence measurements of LHCI complexes from maize

Photoprotective Excess Energy Dissipation. Chapter11

This book introduces the basic physical, chemical, and biological principles underlying the first... more This book introduces the basic physical, chemical, and biological principles underlying the first steps in photosynthesis: light absorption, excitation energy transfer, and charge separation. In Part 1, we introduce pigments and their spectroscopic/ redox properties. In Part 2, pigment-proteins as they occur in various natural systems (plants, algae, photosynthetic bacteria) are described, including the regulation of light harvesting. Part 3 deals with the physics underlying light harvesting: energy transfer and electron transport. Part 4 introduces basic and advanced spectroscopic methods, including data analysis. In Part 5, we discuss artificial and natural photosynthetic systems, how they are assembled, and what the energy transfer properties are

Steady-state spectroscopy of photosystem I light-harvesting complex I (LHC I) from higher plants

Dissipative Pathways in Light-Harvesting Complex II Are Controlled by the Plant Membrane

Green plants prevent photodamage under high light conditions by dissipating excess energy as heat... more Green plants prevent photodamage under high light conditions by dissipating excess energy as heat. Conformational changes of the photosynthetic antenna complexes activate dissipation by leveraging the sensitivity of the photophysics of the chlorophyll and carotenoids to their surrounding protein. However, the mechanisms and site of dissipation are still debated, largely due to two challenges. First, experiments have been performed in detergent, which can induce non-native conformations, or in vivo, where contributions from the multiple complexes cannot be disentangled and are further obfuscated by laser-induced artifacts. Second, because of the ultrafast timescales and large energy gaps involved, measurements lacked the temporal or spectral requirements. Here, we overcome both challenges by applying ultrabroadband two-dimensional electronic spectroscopy to the principal antenna complex, light-harvesting complex II, in a near-native membrane. The spectra show that the membrane enhanc...

A Light Harvesting Complex-Like Protein in Maintenance of Photosynthetic Components in <i>Chlamydomonas</i>

Plant Physiology, Jun 21, 2017

Using a genetic approach, we have identified and characterized a novel protein, named Msf1 (Maint... more Using a genetic approach, we have identified and characterized a novel protein, named Msf1 (Maintenance factor for photosystem I), that is required for the maintenance of specific components of the photosynthetic apparatus in the green alga Chlamydomonas reinhardtii. Msf1 belongs to the superfamily of light-harvesting complex proteins with three transmembrane domains and consensus chlorophyll-binding sites. Loss of Msf1 leads to reduced accumulation of photosystem I and chlorophyll-binding proteins/complexes. Msf1is a component of a thylakoid complex containing key enzymes of the tetrapyrrole biosynthetic pathway, thus revealing a possible link between Msf1 and chlorophyll biosynthesis. Protein interaction assays and greening experiments demonstrate that Msf1 interacts with Copper target homolog1 (CHL27B) and accumulates concomitantly with chlorophyll in Chlamydomonas, implying that chlorophyll stabilizes Msf1. Contrary to other light-harvesting complex-like genes, the expression of Msf1 is not stimulated by high-light stress, but its protein level increases significantly under heat shock, iron and copper limitation, as well as in stationary cells. Based on these results, we propose that Msf1 is required for the maintenance of photosystem I and specific protein-chlorophyll complexes especially under certain stress conditions.

Nonphotochemical Quenching of Chlorophyll Fluorescence in <i>Chlamydomonas reinhardtii</i>

Biochemistry, Jan 13, 2006

Unlike plants, Chlamydomonas reinhardtii shows a restricted ability to develop nonphotochemical q... more Unlike plants, Chlamydomonas reinhardtii shows a restricted ability to develop nonphotochemical quenching upon illumination. Most of this limited quenching is due to state transitions instead of ∆pH-driven high-energy state quenching, qE. The latter could only be observed when the ability of the cells to perform photosynthesis was impaired, either by lowering temperature to ∼0 °C or in mutants lacking RubisCO activity. Two main features were identified that account for the low level of qE in Chlamydomonas. On one hand, the electrochemical proton gradient generated upon illumination is apparently not sufficient to promote fluorescence quenching. On the other hand, the capacity to transduce the presence of a ∆pH into a quenching response is also intrinsically decreased in this alga, when compared to plants. The possible mechanism leading to these differences is discussed.

Supramolecular assembly of chloroplast NADH dehydrogenase-like complex with photosystem I from Arabidopsis thaliana

Molecular Plant, 2022

Cyclic electron transport/flow (CET/CEF) in chloroplasts is a regulatory process essential for op... more Cyclic electron transport/flow (CET/CEF) in chloroplasts is a regulatory process essential for optimization of plant photosynthetic efficiency. A crucial CEF pathway is catalyzed by a membrane-embedded NADH dehydrogenase-like (NDH) complex containing at least 29 protein subunits and associating with photosystem I (PSI) to form the NDH-PSI supercomplex. Here we report the 3.9 Å resolution structure of Arabidopsis thaliana NDH-PSI (AtNDH-PSI) supercomplex. We have constructed structural models for 26 AtNDH subunits, among which 11 subunits are unique to chloroplast and stabilize the core part of NDH complex. In the supercomplex, one NDH can bind up to two PSI-light harvesting complex I (PSI-LHCI) complexes at both sides of its membrane arm. Two minor LHCIs, Lhca5 and Lhca6, each present in one PSI-LHCI, interact with NDH and contribute to the supercomplex formation and stabilization. Our results showed structural details of the supercomplex assembly and provide molecular basis for further investigation of the regulatory mechanism of CEF in plants.

Characterization of magnetic nanoparticles functionalized with albumin for biological applications

2009 International Semiconductor Conference, 2009

In this paper we present a method for the large-scale preparation of biodegradable, biocompatible... more In this paper we present a method for the large-scale preparation of biodegradable, biocompatible magnetic nanospheres, intended to be used for cell labeling techniques in magnetic separation of cells. We obtained magnetite nanoparticles functionalized with albumin using an ultrasonic method, at temperatures between 80-95degC. They were tested in a microfluidic channel. The characterization of the the magnetic nanoparticles functionalized with

Analysis of the Chloroplast Protein Kinase Stt7 during State Transitions

Apple Academic Press eBooks, Apr 19, 2016

State transitions allow for the balancing of the light excitation energy between photosystem I an... more State transitions allow for the balancing of the light excitation energy between photosystem I and photosystem II and for optimal photosynthetic activity when photosynthetic organisms are subjected to changing light conditions. This process is regulated by the redox state of the plastoquinone pool through the Stt7/STN7 protein kinase required for phosphorylation of the light-harvesting complex LHCII and for the reversible displacement of the mobile LHCII between the photosystems. We show that Stt7 is associated with photosynthetic complexes including LHCII, photosystem I, and the cytochrome b 6 f complex. Our data reveal that Stt7 acts in catalytic amounts. We also provide evidence that Stt7 contains a transmembrane region that separates its catalytic kinase domain on the stromal side from its N-terminal end in the thylakoid lumen with two conserved Cys that are critical for its activity and state transitions. On the basis of these data, we propose that the activity of Stt7 is regulated through its transmembrane domain and that a disulfide bond between the two lumen Cys is essential for its activity. The high-light-induced reduction of this bond may occur through a transthylakoid thiol-reducing pathway driven by the ferredoxinthioredoxin system which is also required for cytochrome b 6 f assembly and heme biogenesis.

Magnetic Nanoparticles extracted from magnetotactic bacteria as contrast agents for MRI

Magnetic Nanoparticles extracted from magnetotactic bacteria as contrast agents for MRI Pasquina ... more Magnetic Nanoparticles extracted from magnetotactic bacteria as contrast agents for MRI Pasquina Marzola, Leonardo Ghin, Stefano Tambalo, Giamaica Conti, Silvia Mannucci, Alice Busato, Elvira Fantechi, Claudia Innocenti, Claudio Sangregorio, Alessandro Lascialfari, Tomas Orlando, Roberto Bassi, and Andrea Sbarbati Department of Computer Science, University of Verona, Verona, Italy, Department of Biotechnology, University of Verona, Verona, Italy, Department of Neurological and Movement Science, University of Verona, Verona, Italy, INSTM-LaMM, Dept. of Chemistry, University of Florence, Florence, Italy, Department of Physics, University of Milan, Milan, Italy

Dissipative response to excess light is catalyzed in monomeric and trimeric light harvesting complexes by two independent mechanisms

Nature plants, 2016

Oxygenic photoautotrophs require mechanisms for rapidly matching the level of chlorophyll excited... more Oxygenic photoautotrophs require mechanisms for rapidly matching the level of chlorophyll excited states from light harvesting with the rate of electron transport from water to carbon dioxide. These photoprotective reactions prevent formation of reactive excited states and photoinhibition. The fastest response to excess illumination is the so-called nonphotochemical quenching which, in higher plants, requires the luminal pH sensor PsbS and other yet unidentified components of the photosystem II antenna. Both trimeric light-harvesting complex II (LHCII) and monomeric LHC proteins have been indicated as site(s) of the heat-dissipative reactions. Different mechanisms have been proposed: energy transfer to a lutein quencher in trimers, formation of a zeaxanthin radical cation in monomers. Here, we report on the construction of a mutant lacking all monomeric LHC proteins but retaining LHCII trimers. Its non-photochemical quenching induction rate was substantially slower with respect to the wild type. A carotenoid radical cation signal was detected in the wild type, although it was lost in the mutant. We conclude that non-photochemical quenching is catalysed by two independent mechanisms, with the fastest activated response catalysed within monomeric LHC proteins depending on both zeaxanthin and lutein and on the formation of a radical cation. Trimeric LHCII was responsible for the slowly activated quenching component whereas inclusion in supercomplexes was not required. This latter activity does not depend on lutein nor on charge transfer events, whereas zeaxanthin was essential.

A paler shade of green: engineering cellular chlorophyll content to enhance photosynthesis in crowded environments

New Phytologist

SummaryIn natural ecosystems, plants compete for space, nutrients and light. The optically dense ... more SummaryIn natural ecosystems, plants compete for space, nutrients and light. The optically dense canopies limit the penetration of photosynthetically active radiation and light often becomes a growth‐limiting factor for the understory. The reduced availability of photons in the lower leaf layers is also a major constraint for yield potential in canopies of crop monocultures. Traditionally, crop breeding has selected traits related to plant architecture and nutrient assimilation rather than light use efficiency. Leaf optical density is primarily determined by tissue morphology and by the foliar concentration of photosynthetic pigments (chlorophylls and carotenoids). Most pigment molecules are bound to light‐harvesting antenna proteins in the chloroplast thylakoid membranes, where they serve photon capture and excitation energy transfer toward reaction centers of photosystems. Engineering the abundance and composition of antenna proteins has been suggested as a strategy to improve lig...

Equilibrium distribution of excited states in photosystem II antenna

A chimeric hydrolase-PTXD transgene enables chloroplast-based heterologous protein expression and non-sterile cultivation of Chlamydomonas reinhardtii

Algal Research, 2021

Abstract Photosynthetic microalgae hold great potential as light-driven heterologous protein expr... more Abstract Photosynthetic microalgae hold great potential as light-driven heterologous protein expression hosts. In particular, the algal chloroplast is an ideal sub-cellular site for the compartmentalized synthesis and accumulation of high-value recombinant proteins. However, full integration of transplastomic algal biotechnology in the large-scale production of biocatalysts still suffers from major bottlenecks, such as genetic instability and pest contamination. To enhance the reliability of plastid-based algal expression platforms we developed a self-reinforcing genetic system in Chlamydomonas reinhardtii. We transformed the plastome with a bifunctional transgene encoding an in vivo cleavable fusion polypeptide composed of a hyperthermophilic cellulase and the phosphite dehydrogenase PTXD. The dual use of phosphite as a low-cost, environmentally friendly selective agent and fertilizer afforded axenic algal cultivation via mixotrophic metabolism and efficient expression of the hydrolytic enzyme. This study provides an example of chloroplast genetic engineering in which biosafety is integrated in the sustainable management of microalgal monocultures to produce enzymes with industrial applications.

Look for methods, not conclusions

Cell Death & Disease, 2019

ProteinProtein Interactions Induce pH-Dependent and Zeaxanthin-Independent Photoprotection in the Plant Light-Harvesting Complex, LHCII

Algae: A New Biomass Resource

Springer eBooks, Jul 20, 2018

ABSTRACT Definition of the SubjectAlgae are oxygenic photoautotrophs, offering a very high level ... more ABSTRACT Definition of the SubjectAlgae are oxygenic photoautotrophs, offering a very high level of biodiversity and thus suitable for different practical applications. Today, they are mainly cultivated for human/animal food or to extract high-value chemicals and pharmaceuticals. However, their exploitation could be extended. Algae are attractive as high yield biomass producers, because of the short life cycle, the ability to grow up to very high cell densities, and the easy large-scale cultivation that does not compete with other demands such as those of conventional crops agriculture. Algae can be a resource of renewable, sustainable biofuels. In addition, they can be transformed into “cell factories” to produce recombinant proteins of interest for pharmaceutical companies.IntroductionAlgae are described as “lower” plants that never have true stems, roots, and leaves, and grow photoautotrophically by performing oxygenic photos ...

A kaleidoscope of photosynthetic antenna proteins and their emerging roles

Plant Physiology, Apr 21, 2022

Photosynthetic light-harvesting antennae are pigment-binding proteins that perform one of the mos... more Photosynthetic light-harvesting antennae are pigment-binding proteins that perform one of the most fundamental tasks on Earth, capturing light and transferring energy that enables life in our biosphere. Adaptation to different light environments led to the evolution of an astonishing diversity of light-harvesting systems. At the same time, several strategies have been developed to optimize the light energy input into photosynthetic membranes in response to fluctuating conditions. The basic feature of these prompt responses is the dynamic nature of antenna complexes, whose function readily adapts Update

Mapping out Photoprotective Dissipation in Green Plants Using Ultrabroadband 2D Electronic Spectroscopy

The 22nd International Conference on Ultrafast Phenomena 2020, 2020

Carotenoid-Mediated Light Harvesting in Plants Uncovered with Ultrabroadband Two-Dimensional Electronic Spectroscopy

Frontiers in Optics / Laser Science, 2020

We demonstrate an ultrabroadband two-dimensional electronic spectrometer that maps energy flow ac... more

Time-resolved Fluorescence measurements of LHCI complexes from maize

Photoprotective Excess Energy Dissipation. Chapter11

This book introduces the basic physical, chemical, and biological principles underlying the first... more This book introduces the basic physical, chemical, and biological principles underlying the first steps in photosynthesis: light absorption, excitation energy transfer, and charge separation. In Part 1, we introduce pigments and their spectroscopic/ redox properties. In Part 2, pigment-proteins as they occur in various natural systems (plants, algae, photosynthetic bacteria) are described, including the regulation of light harvesting. Part 3 deals with the physics underlying light harvesting: energy transfer and electron transport. Part 4 introduces basic and advanced spectroscopic methods, including data analysis. In Part 5, we discuss artificial and natural photosynthetic systems, how they are assembled, and what the energy transfer properties are

Steady-state spectroscopy of photosystem I light-harvesting complex I (LHC I) from higher plants

Dissipative Pathways in Light-Harvesting Complex II Are Controlled by the Plant Membrane

Green plants prevent photodamage under high light conditions by dissipating excess energy as heat... more Green plants prevent photodamage under high light conditions by dissipating excess energy as heat. Conformational changes of the photosynthetic antenna complexes activate dissipation by leveraging the sensitivity of the photophysics of the chlorophyll and carotenoids to their surrounding protein. However, the mechanisms and site of dissipation are still debated, largely due to two challenges. First, experiments have been performed in detergent, which can induce non-native conformations, or in vivo, where contributions from the multiple complexes cannot be disentangled and are further obfuscated by laser-induced artifacts. Second, because of the ultrafast timescales and large energy gaps involved, measurements lacked the temporal or spectral requirements. Here, we overcome both challenges by applying ultrabroadband two-dimensional electronic spectroscopy to the principal antenna complex, light-harvesting complex II, in a near-native membrane. The spectra show that the membrane enhanc...