The diversity and coevolution of Rubisco, plastids, pyrenoids, and chloroplast-based CO2-concentrating mechanisms in algae

1998 ◽  
Vol 76 (6) ◽  
pp. 1052-1071 ◽  
Author(s):  
Murray R Badger ◽  
T John Andrews ◽  
S M Whitney ◽  
Martha Ludwig ◽  
David C Yellowlees ◽  
...  
Keyword(s):  
Higher Plants ◽  
Algal Species ◽  
Future Research ◽  
Kinetic Properties ◽  
Diverse Range ◽  
Photosynthetic Physiology ◽  
Green Algal ◽  
Concentrating Mechanism ◽  
Co2 Concentrating Mechanisms ◽  
Red Form

Algae have adopted two primary strategies to maximize the performance of Rubisco in photosynthetic CO2 fixation. This has included either the development of a CO2-concentrating mechanism (CCM), based at the level of the chloroplast, or the evolution of the kinetic properties of Rubisco. This review examines the potential diversity of both Rubisco and chloroplast-based CCMs across algal divisions, including both green and nongreen algae, and seeks to highlight recent advances in our understanding of the area and future areas for research. Overall, the available data show that Rubisco enzymes from algae have evolved a higher affinity for CO2 when the algae have adopted a strategy for CO2 fixation that does not utilise a CCM. This appears to be true of both Green and Red Form I Rubisco enzymes found in green and nongreen algae, respectively. However, the Red Form I Rubisco enzymes present in nongreen algae appear to have reduced oxygenase potential at air level of O2. This has resulted in a photosynthetic physiology with a reduced potential to be inhibited by O2 and a reduced need to deal with photorespiration. In the limited number of microalgae that have been examined, there is a strong correlation between the existence of a high-affinity CCM physiology and the presence of pyrenoids in all algae, highlighting the potential importance of these chloroplast Rubisco-containing bodies. However, in macroalgae, there is greater diversity in the apparent relationships between pyrenoids and chloroplast features and the CCM physiology that the species shows. There are many examples of microalgae and macroalgae with variations in the presence and absence of pyrenoids as well as single and multiple chloroplasts per cell. This occurs in both green and nongreen algae and should provide ample material for extending studies in this area. Future research into the function of the pyrenoid and other chloroplast features, such as thylakoids, in the operation of a chloroplast-based CCM needs to be addressed in a diverse range of algal species. This should be approached together with assessment of the coevolution of Rubisco, particularly the evolution of Red Form I Rubisco enzymes, which appear to achieve superior kinetic characteristics when compared with the Rubisco of C3 higher plants, which are derived from green algal ancestors.Key words: Rubisco, CO2-concentrating mechanism, carbonic anhydrase, aquatic photosynthesis, algae, pyrenoids, inorganic carbon.

scholarly journals With a little help from their friends: Algae acquire vitamins through intimate associations with bacteria

2006 ◽  
Vol 28 (4) ◽  
pp. 17-20
Author(s):  
Martin T. Croft and Alison G. Smith
Keyword(s):  
Aquatic Plants ◽  
Higher Plants ◽  
Inorganic Compounds ◽  
Algal Species ◽  
Associated Bacteria ◽  
Marine Systems ◽  
Green Algal ◽  
The World ◽  
Algae And Bacteria ◽  
Amazonian Rainforest

Everyone is familiar with the concept of the Amazonian rainforest as the lungs of the world, but what is less well known is that 50% of the world's photosynthesis is carried out by algae1 -- simple aquatic plants found in all freshwater and marine systems. By analogy with higher plants, which evolved from the green algal lineage, it is assumed that algae are autotrophic, requiring merely light and a mixture of inorganic compounds to grow. It is perhaps surprising therefore to discover that more than half of all algal species require exogenous cobalamin for growth. Recent work has established that the source of the vitamin is from closely associated bacteria, which appear to live in symbiosis with the algal cells. At the same time, reports of other interactions between algae and bacteria are appearing, prompting a rethink on the concept of organisms existing as separate entities, and having profound implications for our understanding of oceanic ecosystems.

scholarly journals Measuring Digital Competence and ICT Literacy: An Exploratory Study of In-Service English Language Teachers in the Context of Saudi Arabia

2017 ◽  
Vol 10 (12) ◽  
pp. 38 ◽  
Author(s):  
Ahmed Abdulteeef M. Al Khateeb
Keyword(s):  
Saudi Arabia ◽  
Foreign Language ◽  
English Language ◽  
Research Question ◽  
Language Teachers ◽  
Future Research ◽  
Ict Literacy ◽  
Digital Competence ◽  
Diverse Range ◽  
English Language Teachers

The purpose of this research is to measure in-service English language teachers' digital competence, particularly for the enhancement of teaching English as a second/foreign language in schools in Saudi Arabia. Information and communication technology (ICT) knowledge is currently considered as a vital skill for foreign language teachers in addition to their linguistic competence. Recently, there has been a focus on digital competence, since it can be regarded as a gateway for enriching knowledge, economies, societies and individuals. There is also a massive need for teachers to assess their own digital competence according to non-conventional norms (i.e., having the ability to share content and manage information). In light of this rationale, this paper investigates the following research question: to what extent are English language teachers in Saudi Arabia digitally competent and in what aspects? This study used a standardized questionnaire that was constructed using a validated comprehensive framework. This instrument was designed to assess the professional capability of English language teachers in terms of their willingness and readiness to use ICTs along with their current digital competence used throughout their teaching and educational practices. The research included a diverse range of participants who come from various backgrounds, genders and experiences. The study was concluded with a presentation of useful recommendations and key research questions for future research.

scholarly journals Species Diversity and Secondary Metabolites of Sarcophyton-Associated Marine Fungi

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3227
Author(s):  
Yuanwei Liu ◽  
Kishneth Palaniveloo ◽  
Siti Aisyah Alias ◽  
Jaya Seelan Sathiya Seelan
Keyword(s):  
Secondary Metabolites ◽  
Soft Coral ◽  
Marine Fungi ◽  
Indole Alkaloids ◽  
Structural Diversity ◽  
Future Research ◽  
Soft Corals ◽  
Diverse Range ◽  
Symbiotic Relationships ◽  
Bioactive Secondary Metabolites

Soft corals are widely distributed across the globe, especially in the Indo-Pacific region, with Sarcophyton being one of the most abundant genera. To date, there have been 50 species of identified Sarcophyton. These soft corals host a diverse range of marine fungi, which produce chemically diverse, bioactive secondary metabolites as part of their symbiotic nature with the soft coral hosts. The most prolific groups of compounds are terpenoids and indole alkaloids. Annually, there are more bio-active compounds being isolated and characterised. Thus, the importance of the metabolite compilation is very much important for future reference. This paper compiles the diversity of Sarcophyton species and metabolites produced by their associated marine fungi, as well as the bioactivity of these identified compounds. A total of 88 metabolites of structural diversity are highlighted, indicating the huge potential these symbiotic relationships hold for future research.

Leptochlorella corticola gen. et sp. nov. and Kalinella apyrenoidosa sp. nov.: two novel Chlorella-like green microalgae (Trebouxiophyceae, Chlorophyta) from subaerial habitats

2013 ◽  
Vol 63 (Pt_1) ◽  
pp. 377-387 ◽  
Author(s):  
Jiří Neustupa ◽  
Yvonne Němcová ◽  
Jana Veselá ◽  
Jana Steinová ◽  
Pavel Škaloud
Keyword(s):  
18S Rrna ◽  
New Genus ◽  
Gene Sequence ◽  
Novel Species ◽  
Algal Species ◽  
18S Rrna Gene ◽  
Tree Bark ◽  
Rrna Gene ◽  
Green Microalgae ◽  
Green Algal

The diversity of green microalgae in subaerial habitats remains largely unexplored and a number of new genus- and species-level lineages have been discovered recently. The traditional green algal genus, Chlorella, which accommodated coccoid unicellular green algal species with globular to oval cells, reproducing entirely by autospores, has been found to be polyphyletic. In this study, we provide a detailed characterization of two strains of microalgae isolated from tree bark in the Mediterranean. These algae share the general Chlorella-like morphology and their 18S rRNA and rbcL gene sequences place them in the Trebouxiophyceae. Strain CAUP H8401 forms an independent trebouxiophycean lineage, together with three previously published 18S rRNA gene environmental sequences of undescribed microalgae, which were retrieved from profoundly different habitats. In contrast, strain CAUP H7902 is related to Kalinella bambusicola in the Watanabea clade of the Trebouxiophyceae on the basis of its 18S rRNA gene sequence. This relationship is also supported by the rbcL gene sequence, acquired from the type strain of K. bambusicola. The investigated strains are described as representatives of a novel species in a new genus, Leptochlorella corticola gen. et sp. nov., and a novel species, Kalinella apyrenoidosa sp. nov., according to the International Code of Nomenclature for Algae, Fungi and Plants.

scholarly journals A Linkage Map and QTL Analysis for Pyrethroid Resistance in the Bed Bug Cimex lectularius

2016 ◽  
Vol 6 (12) ◽  
pp. 4059-4066 ◽  
Author(s):  
Toby Fountain ◽  
Mark Ravinet ◽  
Richard Naylor ◽  
Klaus Reinhardt ◽  
Roger K Butlin
Keyword(s):  
Insecticide Resistance ◽  
Candidate Gene ◽  
Linkage Map ◽  
Pyrethroid Resistance ◽  
Cimex Lectularius ◽  
Future Research ◽  
Potential Candidate ◽  
Pest Species ◽  
Diverse Range ◽  
Bed Bug

Abstract The rapid evolution of insecticide resistance remains one of the biggest challenges in the control of medically and economically important pests. Insects have evolved a diverse range of mechanisms to reduce the efficacy of the commonly used classes of insecticides, and finding the genetic basis of resistance is a major aid to management. In a previously unstudied population, we performed an F2 resistance mapping cross for the common bed bug, Cimex lectularius, for which insecticide resistance is increasingly widespread. Using 334 SNP markers obtained through RAD-sequencing, we constructed the first linkage map for the species, consisting of 14 putative linkage groups (LG), with a length of 407 cM and an average marker spacing of 1.3 cM. The linkage map was used to reassemble the recently published reference genome, facilitating refinement and validation of the current genome assembly. We detected a major QTL on LG12 associated with insecticide resistance, occurring in close proximity (1.2 Mb) to a carboxylesterase encoding candidate gene for pyrethroid resistance. This provides another example of this candidate gene playing a major role in determining survival in a bed bug population following pesticide resistance evolution. The recent availability of the bed bug genome, complete with a full list of potential candidate genes related to insecticide resistance, in addition to the linkage map generated here, provides an excellent resource for future research on the development and spread of insecticide resistance in this resurging pest species.

scholarly journals Workshop on Emerging Technology and Data Analytics for Behavioral Health (Preprint)

2017 ◽  
Author(s):  
David Kotz ◽  
Sarah E Lord ◽  
A James O'Malley ◽  
Luke Stark ◽  
Lisa A. Marsch
Keyword(s):  
Behavioral Health ◽  
Data Analytics ◽  
Health Behavior Change ◽  
Emerging Technology ◽  
Mobile Technologies ◽  
Dartmouth College ◽  
Future Research ◽  
Diverse Range ◽  
User Experience Design ◽  
Health Technologies

UNSTRUCTURED Wearable and portable digital devices can support self-monitoring for patients with chronic medical conditions, individuals seeking to reduce stress, and people seeking to modify health-related behaviors such as substance use or overeating. The resulting data may be used directly by a consumer, or shared with a clinician for treatment, a caregiver for assistance, or a health coach for support. The data can also be used by researchers to develop and evaluate just-in-time interventions that leverage mobile technology to help individuals manage their symptoms and behavior in real time and as needed. Such wearable systems have huge potential for promoting delivery of anywhere-anytime health care, improving public health, and enhancing the quality of life for many people. The Center for Technology and Behavioral Health at Dartmouth College, a P30 “Center of Excellence” supported by the National Institute on Drug Abuse at the National Institutes of Health, conducted a workshop in February 2017 on innovations in emerging technology, user-centered design, and data analytics for behavioral health, with presentations by a diverse range of experts in the field. The workshop focused on wearable and mobile technologies being used in clinical and research contexts, with an emphasis on applications in mental health, addiction, and health behavior change. In this paper, we summarize the workshop panels on mobile sensing, user experience design, statistics and machine learning, and privacy and security, and conclude with suggested research directions for this important and emerging field of applying digital approaches to behavioral health. Workshop insights yielded four key directions for future research: (1) a need for behavioral health researchers to work iteratively with experts in emerging technology and data analytics, (2) a need for research into optimal user-interface design for behavioral health technologies, (3) a need for privacy-oriented design from the beginning of a novel technology, and (4) the need to develop new analytical methods that can scale to thousands of individuals and billions of data points.

scholarly journals Within-Arctic horizontal gene transfer as a driver of convergent evolution in distantly related microalgae

2021 ◽  
Author(s):  
Richard G Dorrell ◽  
Alan Kuo ◽  
Zoltan Fussy ◽  
Elisabeth H Richardson ◽  
Asaf Salamov ◽  
...  
Keyword(s):  
Sequence Data ◽  
Sequence Similarity ◽  
Algal Species ◽  
Gene Families ◽  
The Arctic ◽  
Arctic Water ◽  
Diverse Range ◽  
Binding Domains ◽  
Ice Binding ◽  
Ice Conditions

The Arctic Ocean is being impacted by warming temperatures, increasing freshwater and highly variable ice conditions. The microalgal communities underpinning Arctic marine food webs, once thought to be dominated by diatoms, include a phylogenetically diverse range of small algal species, whose biology remains poorly understood. Here, we present genome sequences of a cryptomonad, a haptophyte, a chrysophyte, and a pelagophyte, isolated from the Arctic water column and ice. Comparing protein family distributions and sequence similarity across a densely-sampled set of algal genomes and transcriptomes, we note striking convergences in the biology of distantly related small Arctic algae, compared to non-Arctic relatives; although this convergence is largely exclusive of Arctic diatoms. Using high-throughput phylogenetic approaches, incorporating environmental sequence data from Tara Oceans, we demonstrate that this convergence was partly explained by horizontal gene transfers (HGT) between Arctic species, in over at least 30 other discrete gene families, and most notably in ice-binding domains (IBD). These Arctic-specific genes have been repeatedly transferred between Arctic algae, and are independent of equivalent HGTs in the Antarctic Southern Ocean. Our data provide insights into the specialised Arctic marine microbiome, and underlines the role of geographically-limited HGT as a driver of environmental adaptation in eukaryotic algae.

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