Formyl group modification of chlorophylla: a major evolutionary mechanism in oxygenic photosynthesis

2012 ◽  
Vol 36 (3) ◽  
pp. 521-527 ◽  
Author(s):  
MARTIN SCHLIEP ◽  
GERMÁN CAVIGLIASSO ◽  
ROSANNE G. QUINNELL ◽  
ROBERT STRANGER ◽  
ANTHONY W. D. LARKUM
Keyword(s):  
Oxygenic Photosynthesis ◽  
Formyl Group ◽  
Evolutionary Mechanism ◽  
Group Modification

Revising Plants, man and life: Edgar Anderson reshapes a classic book

2003 ◽  
Vol 30 (1) ◽  
pp. 85-96 ◽  
Author(s):  
Kim Kleinman
Keyword(s):  
Twentieth Century ◽  
Evolutionary Theory ◽  
Evolutionary Synthesis ◽  
Ernst Mayr ◽  
Active Participant ◽  
Evolutionary Mechanism ◽  
Popular Work ◽  
Scientific Attention ◽  
Key Events ◽  
Jesup Lectures

On at least four occasions, Edgar Anderson (1897–1969) began revising his book Plants, man and life (1952). Given both its place in Anderson's career and his place in the development of evolutionary theory in the mid-twentieth century, the emendations are noteworthy. Though a popular work, Plants, man and life served as the distillation of Anderson's ideas on hybridization as an evolutionary mechanism, the need for more scientific attention on domesticated and semi-domesticated plants, and the opportunities such plants provided for the study of evolution. Anderson was an active participant in several key events in what historians have come to call the Evolutionary Synthesis. For example, he and Ernst Mayr shared the 1941 Jesup Lectures on “Systematics and the origin of species”. Anderson's proposed revisions to his book reflect both an attempt to soften certain acerbic comments as well as an attempt to recast the book as a whole.

scholarly journals Cyanobakterien als Biokatalysatoren

BIOspektrum ◽  
2021 ◽  
Vol 27 (2) ◽  
pp. 208-210
Author(s):  
Marc M. Nowaczyk ◽  
Hanna C. Grimm ◽  
Leen Assil-Companioni ◽  
Robert Kourist
Keyword(s):  
Natural Process ◽  
Oxygenic Photosynthesis ◽  
Phototrophic Microorganisms ◽  
Electron Sink ◽  
Pcc 6803

AbstractThe highly optimized natural process of oxygenic photosynthesis leads to the formation of redox equivalents, such as NADPH, that can be used to fuel heterologous biotransformations in phototrophic microorganisms. We investigated the reduction of 2-methylmaleimide by the ene-reductase YqjM in the cyanobacterium Synechocystis sp. PCC 6803 and doubled the productivity of the cells by inactivating flavodiironproteins (FDPs) as competing electron sink under self-shading conditions, reaching 18.3 mmol h−1 L−1.

scholarly journals Recovery of Unicellular Cyanobacteria from Nitrogen Chlorosis: A Model for Resuscitation of Dormant Bacteria

2021 ◽  
pp. 1-10
Author(s):  
Niels Neumann ◽  
Sofia Doello ◽  
Karl Forchhammer
Keyword(s):  
Nitrogen Starvation ◽  
Oxygenic Photosynthesis ◽  
Cellular Activity ◽  
Input Output ◽  
Minimal Set ◽  
Operation System ◽  
Developmental Transitions ◽  
The Awakening ◽  
Output System ◽  
Basic Input

Nitrogen starvation induces developmental transitions in cyanobacteria. Whereas complex multicellular cyanobacteria of the order Nostocales can differentiate specialized cells that perform nitrogen fixation in the presence of oxygenic photosynthesis, non-diazotrophic unicellular strains, such as <i>Synechococcus elongatus</i> or <i>Synechocystis</i> PCC 6803, undergo a transition into a dormant non-growing state. Due to loss of pigments during this acclimation, the process is termed chlorosis. Cells maintain viability in this state for prolonged periods of time, until they encounter a useable nitrogen source, which triggers a highly coordinated awakening process, termed resuscitation. The minimal set of cellular activity that maintains the viability of cells during chlorosis and ensures efficient resuscitation represents the organism’s equivalent of the BIOS, the basic input/output system of a computer, that helps “booting” the operation system after switching on. This review summarizes the recent research in the resuscitation of cyanobacteria, representing a powerful model for the awakening of dormant bacteria.

scholarly journals Antioxidant and Signaling Role of Plastid-Derived Isoprenoid Quinones and Chromanols

2021 ◽  
Vol 22 (6) ◽  
pp. 2950
Author(s):  
Beatrycze Nowicka ◽  
Agnieszka Trela-Makowej ◽  
Dariusz Latowski ◽  
Kazimierz Strzalka ◽  
Renata Szymańska
Keyword(s):  
Current Knowledge ◽  
Stress Factors ◽  
Oxygenic Photosynthesis ◽  
Ros Generation ◽  
Main Site ◽  
Storage Lipids ◽  
Abiotic Stress Factors ◽  
Cell Components ◽  
And Function

Plant prenyllipids, especially isoprenoid chromanols and quinols, are very efficient low-molecular-weight lipophilic antioxidants, protecting membranes and storage lipids from reactive oxygen species (ROS). ROS are byproducts of aerobic metabolism that can damage cell components, they are also known to play a role in signaling. Plants are particularly prone to oxidative damage because oxygenic photosynthesis results in O2 formation in their green tissues. In addition, the photosynthetic electron transfer chain is an important source of ROS. Therefore, chloroplasts are the main site of ROS generation in plant cells during the light reactions of photosynthesis, and plastidic antioxidants are crucial to prevent oxidative stress, which occurs when plants are exposed to various types of stress factors, both biotic and abiotic. The increase in antioxidant content during stress acclimation is a common phenomenon. In the present review, we describe the mechanisms of ROS (singlet oxygen, superoxide, hydrogen peroxide and hydroxyl radical) production in chloroplasts in general and during exposure to abiotic stress factors, such as high light, low temperature, drought and salinity. We highlight the dual role of their presence: negative (i.e., lipid peroxidation, pigment and protein oxidation) and positive (i.e., contribution in redox-based physiological processes). Then we provide a summary of current knowledge concerning plastidic prenyllipid antioxidants belonging to isoprenoid chromanols and quinols, as well as their structure, occurrence, biosynthesis and function both in ROS detoxification and signaling.

scholarly journals Niche Construction Theory in Archaeology: A Critical Review

2021 ◽  
Author(s):  
Robert N. Spengler
Keyword(s):  
Social Sciences ◽  
Biological Sciences ◽  
Niche Construction ◽  
Heuristic Function ◽  
Evolutionary Mechanism ◽  
Ecosystem Impacts ◽  
Niche Construction Theory ◽  
The Past ◽  
The Social ◽  
Explanatory Mechanism

AbstractOver the past decade, niche construction theory (NCT) has been one of the fastest-growing theories or scholarly approaches in the social sciences, especially within archaeology. It was proposed in the biological sciences 25 years ago and is often referred to as a neglected evolutionary mechanism. Given its rapid acceptance by the archaeological community, it is important that scholars consider how it is being applied and look for discrepancies between applications of the concept. Many critical discussions of NCT have already been published, but most of them are in biology journals and may be overlooked by scholars in the social sciences. In this manuscript, my goal is to synthesis the criticisms of NCT, better allowing archaeologists to independently evaluate its usefulness. I focus on the claims of novelty and differences between NCT and other approaches to conceptualizing anthropogenic ecosystem impacts and culture-evolution feedbacks. I argue that the diverse concepts currently included in the wide-reaching purview of NCT are not new, but the terminology is and may be useful to some scholars. If proponents of the concept are able to unify their ideas, it may serve a descriptive function, but given that lack of a testable explanatory mechanism, it does not have a clear heuristic function.

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