scholarly journals Integrative analysis of the hydroxypyruvate reductases revealing their distinct roles in photorespiration of Chlamydomonas

2021 ◽  
Author(s):  
Menglin Shi ◽  
Lei Zhao ◽  
Yong Wang
Keyword(s):  
Sequence Comparison ◽  
Higher Plants ◽  
Crop Improvement ◽  
Activity Measurement ◽  
Quinone Oxidoreductase ◽  
Hydroxypyruvate Reductase ◽  
Eukaryotic Organism ◽  
Physiological Metabolism ◽  
Genes Encoding ◽  
Glyoxylate Reductase

Photorespiration plays an important role in maintaining normal physiological metabolism in higher plants and other oxygenic organisms such as algae. The unicellular eukaryotic organism Chlamydomonas is reported to have a different photorespiration system from that in higher plants, and only two out of nine genes encoding photorespiratory enzymes have been experimentally characterized. Hydroxypyruvate reductase (HPR), which is responsible for the conversion of hydroxypyruvate into glycerate, is poorly understood and not yet explored in Chlamydomonas. To identify the candidate genes encoding hydroxypyruvate reductase in Chlamydomonas (CrHPR) and uncover their elusive functions, we performed sequence comparison, enzyme activity measurement, subcellular localization, and analysis of knockout/knockdown strains. Together we identify five proteins to be good candidates as CrHPRs, all of which are detected with the activity of hydroxypyruvate reductase. CrHPR1, a NADH-dependent enzyme in mitochondria, may function as the major component of photorespiration, and deletion of CrHPR1 causes severe photorespiratory defects. CrHPR2 takes parts in the cytosolic bypass of photorespiration as the compensatory pathway of CrHPR1 for the reduction of hydroxypyruvate. CrHPR4, with NADH as the cofactor, may participate in photorespiration by acting as the chloroplastidial glyoxylate reductase in glycolate-quinone oxidoreductase system. Therefore, our results reveal that the CrHPRs are far more complex than previously recognized, and provide a greatly expanded knowledge base for studies to understand how CrHPRs perform their functions in photorespiration. These will facilitate the genetic engineering for crop improvement by synthetic biology.

scholarly journals Identification and Characterization of Genes Encoding the Hydroxypyruvate Reductases in Chlamydomonas Reveal Their Distinct Roles in Photorespiration

2021 ◽  
Vol 12 ◽  
Author(s):  
Menglin Shi ◽  
Lei Zhao ◽  
Yong Wang
Keyword(s):  
Higher Plants ◽  
Crop Improvement ◽  
Activity Measurement ◽  
Quinone Oxidoreductase ◽  
Hydroxypyruvate Reductase ◽  
Eukaryotic Organism ◽  
Genes Encoding ◽  
Identification And Characterization ◽  
Glyoxylate Reductase

Photorespiration plays an important role in maintaining normal physiological metabolism in higher plants and other oxygenic organisms, such as algae. The unicellular eukaryotic organism Chlamydomonas is reported to have a photorespiration system different from that in higher plants, and only two out of nine genes encoding photorespiratory enzymes have been experimentally characterized. Hydroxypyruvate reductase (HPR), which is responsible for the conversion of hydroxypyruvate into glycerate, is poorly understood and not yet explored in Chlamydomonas. To identify the candidate genes encoding hydroxypyruvate reductases in Chlamydomonas (CrHPR) and uncover their elusive functions, we performed sequence comparison, enzyme activity measurement, subcellular localization, and analysis of knockout/knockdown strains. Together, we identify five proteins to be good candidates for CrHPRs, all of which are detected with the activity of hydroxypyruvate reductase. CrHPR1, a nicotinamide adenine dinucleotide (NADH)-dependent enzyme in mitochondria, may function as the major component of photorespiration. Its deletion causes severe photorespiratory defects. CrHPR2 takes part in the cytosolic bypass of photorespiration as the compensatory pathway of CrHPR1 for the reduction of hydroxypyruvate. CrHPR4, with NADH as the cofactor, may participate in photorespiration by acting as the chloroplastidial glyoxylate reductase in glycolate-quinone oxidoreductase system. Therefore, the results reveal that CrHPRs are far more complex than previously recognized and provide a greatly expanded knowledge base for studies to understand how CrHPRs perform their functions in photorespiration. These will facilitate both modification of photorespiration and genetic engineering for crop improvement by synthetic biology.

Structure, expression, chromosomal location and product of the gene encoding Adh2 in Petunia.

Genetics ◽  
1993 ◽  
Vol 133 (4) ◽  
pp. 999-1007
Author(s):  
R G Gregerson ◽  
L Cameron ◽  
M McLean ◽  
P Dennis ◽  
J Strommer
Keyword(s):  
Chromosomal Location ◽  
Higher Plants ◽  
Gene Encoding ◽  
Genomic Libraries ◽  
Regulatory Strategy ◽  
Adh1 Gene ◽  
Adh Genes ◽  
Genes Encoding ◽  
Adh Gene ◽  
Polymerase Chain

Abstract In most higher plants the genes encoding alcohol dehydrogenase comprise a small gene family, usually with two members. The Adh1 gene of Petunia has been cloned and analyzed, but a second identifiable gene was not recovered from any of three genomic libraries. We have therefore employed the polymerase chain reaction to obtain the major portion of a second Adh gene. From sequence, mapping and northern data we conclude this gene encodes ADH2, the major anaerobically inducible Adh gene of Petunia. The availability of both Adh1 and Adh2 from Petunia has permitted us to compare their structures and patterns of expression to those of the well-studied Adh genes of maize, of which one is highly expressed developmentally, while both are induced in response to hypoxia. Despite their evolutionary distance, evidenced by deduced amino acid sequence as well as taxonomic classification, the pairs of genes are regulated in strikingly similar ways in maize and Petunia. Our findings suggest a significant biological basis for the regulatory strategy employed by these distant species for differential expression of multiple Adh genes.

scholarly journals Gene targeting facilitated by engineered sequence-specific nucleases and its potential for applications in crop improvement

2021 ◽  
Author(s):  
Daisuke Miki ◽  
Rui Wang ◽  
Jing Li ◽  
Dali Kong ◽  
Lei Zhang ◽  
...  
Keyword(s):  
Gene Targeting ◽  
Agronomic Traits ◽  
Higher Plants ◽  
Crop Improvement ◽  
Strand Break ◽  
End Joining ◽  
Homology Directed Repair ◽  
Target Dna ◽  
Targeted Gene Editing ◽  
Non Homologous End Joining

Abstract Humans are currently facing the problem of how to ensure that there is enough food to feed all of the world’s population. Ensuring that the food supply is sufficient will likely require the modification of crop genomes to improve their agronomic traits. The development of engineered sequence-specific nucleases (SSNs) paved the way for targeted gene editing in organisms, including plants. SSNs generate a double-strand break (DSB) at the target DNA site in a sequence-specific manner. These DSBs are predominantly repaired via error-prone non-homologous end joining (NHEJ), and are only rarely repaired via error-free homology-directed repair (HDR) if an appropriate donor template is provided. Gene targeting (GT), i.e., the integration or replacement of a particular sequence, can be achieved with combinations of SSNs and repair donor templates. Although its efficiency is extremely low, GT has been achieved in some higher plants. Here, we provide an overview of SSN-facilitated GT in higher plants and discuss the potential of GT as a powerful tool for generating crop plants with desirable features.

scholarly journals Higher plants contain homologs of the bacterial celA genes encoding the catalytic subunit of cellulose synthase.

1996 ◽  
Vol 93 (22) ◽  
pp. 12637-12642 ◽  
Author(s):  
J. R. Pear ◽  
Y. Kawagoe ◽  
W. E. Schreckengost ◽  
D. P. Delmer ◽  
D. M. Stalker
Keyword(s):  
Higher Plants ◽  
Cellulose Synthase ◽  
Catalytic Subunit ◽  
Genes Encoding

scholarly journals Floral Diversity and Genetic Structure of Tea Germplasm of Sri Lanka

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Mahasen Achintiya Bandara Ranatunga ◽  
Jeevan Dananjaya Kottawa Arachchi ◽  
Kumudini Gunasekare ◽  
Deepthi Yakandawala
Keyword(s):  
Genetic Structure ◽  
Sri Lanka ◽  
Higher Plants ◽  
Crop Improvement ◽  
Germplasm Collection ◽  
Morphological Characters ◽  
Floral Traits ◽  
Sufficient Information ◽  
Floral Diversity ◽  
Grouping Pattern

The role of tea germplasm in crop improvement, though well recognized, yet lacks sufficient information depriving its optimum use. About 600 accessions are conserved as tea germplasm in Sri Lanka and only 4% have been frequently utilized in breeding. Floral morphological characters are useful descriptors for preliminary characterization of genetic resources and particularly pistil traits are considered as reliable criteria in taxonomical studies of higher plants. The objectives of the present study were to conduct a comprehensive analysis on floral diversity of tea germplasm to determine the nature and extent of genetic structure of tea germplasm and to categorize accessions into major taxa. Eighty-nine accessions from the tea germplasm were characterized using 16 floral traits. Results indicated presence of considerable variation among germplasm accessions. Accessions were categorized into five different groups based on the diversity of floral traits and highly discriminating accessions were identified based on the grouping pattern. Among the traits, pistil traits were highly variable compared to other traits. Tea germplasm is predominantly represented by Cambod type accessions (68%) followed by Assam types (20%). Availability of China type accessions is low. Gaps in the germplasm collection were identified and information generated can be used for decision making in future germplasm exploration missions and breeding programme.

scholarly journals The JmjC Domain Histone Demethylase Ndy1 Regulates Redox Homeostasis and Protects Cells from Oxidative Stress

2008 ◽  
Vol 28 (24) ◽  
pp. 7451-7464 ◽  
Author(s):  
Christos Polytarchou ◽  
Raymond Pfau ◽  
Maria Hatziapostolou ◽  
Philip N. Tsichlis
Keyword(s):  
Redox Regulation ◽  
Replicative Senescence ◽  
Redox Homeostasis ◽  
Histone H3 ◽  
Quinone Oxidoreductase ◽  
Expression Of Genes ◽  
Genes Encoding ◽  
Jmjc Domain ◽  
Peptidase Inhibitor ◽  
Induced Apoptosis

ABSTRACT The histone H3 demethylase Ndy1/KDM2B protects cells from replicative senescence. Changes in the metabolism of reactive oxygen species (ROS) are important for establishing senescence, suggesting that Ndy1 may play a role in redox regulation. Here we show that Ndy1 protects from H2O2-induced apoptosis and G2/M arrest and inhibits ROS-mediated signaling and DNA damage, while knockdown of Ndy1 has the opposite effects. Consistent with these observations, whereas Ndy1 overexpression promotes H2O2 detoxification, Ndy1 knockdown inhibits it. Ndy1 promotes the expression of genes encoding the antioxidant enzymes aminoadipic semialdehyde synthase (Aass), NAD(P)H quinone oxidoreductase-1 (Nqo1), peroxiredoxin-4 (Prdx4), and serine peptidase inhibitor b1b (Serpinb1b) and represses the expression of interleukin-19. At least two of these genes (Nqo1 and Prdx4) are regulated directly by Ndy1, which binds to specific sites within their promoters and demethylates promoter-associated histone H3 dimethylated at K36 and histone H3 trimethylated at K4. Simultaneous knockdown of Aass, Nqo1, Prdx4, and Serpinb1b in Ndy1-expressing cells to levels equivalent to those detected in control cells was sufficient to suppress the Ndy1 redox phenotype.

scholarly journals Transcriptional profiling of gametogenesis in the green seaweed Ulva mutabilis identifies an RWP‐RK transcription factors linked to reproduction

2021 ◽  
Author(s):  
Xiaojie Liu ◽  
Jonas Blomme ◽  
Kenny Bogaert ◽  
Sofie D’hondt ◽  
Thomas Wichard ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Transcription Factors ◽  
Sexual Reproduction ◽  
Higher Plants ◽  
Crop Improvement ◽  
Functional Characterization ◽  
Land Plants ◽  
Alternative Source ◽  
Starting Point ◽  
Green Seaweed

Abstract Background The molecular mechanism underlying sexual reproduction in land plants is well understood in model plants and is a target for crop improvement. However, unlike land plants, the genetic basis involved in triggering reproduction and gamete formation remains elusive in most seaweeds, which are increasingly viewed as an alternative source of functional food and feedstock for energy applications. Results Gametogenesis of Ulva mutabilis, a model organism for green seaweeds, is studied. We analyze transcriptome dynamics at different time points during gametogenesis following induction of reproduction by fragmentation and removal of sporulation inhibitors. Analyses demonstrate that 45% of the genes in the genome are differentially expressed during gametogenesis. We identified several transcription factors that potentially play a key role in the early gametogenesis of Ulva given the function of their homologs in higher plants and microalgae. In particular, the detailed expression pattern of an evolutionary conserved transcription factor containing an RWP-RK domain suggests a key role during Ulva gametogenesis. Conclusions Transcriptomic analyses of gametogenesis in the green seaweed Ulva highlight the importance of a conserved RWP-RK transcription factor in induction of sexual reproduction. The identification of putative master regulators of gametogenesis provides a starting point for further functional characterization.

scholarly journals MOLECULAR ANALYSIS OF HEAT STRESS PROTEINS IN HIGHER PLANTS

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1175e-1175
Author(s):  
Elizabeth Vierling
Keyword(s):  
Stress Proteins ◽  
Higher Plants ◽  
Intracellular Localization ◽  
Normal Growth ◽  
High Temperature Stress ◽  
Cellular Processes ◽  
Evolutionarily Conserved ◽  
Genes Encoding ◽  
Heat Stress Proteins ◽  
Shock Proteins

When plants experience high temperature stress, they respond by synthesizing a discrete set of proteins called heat shock proteins (HSPs). This response is not unique to plants, but is observed in all other eukaryotes. It is now known that the HSPs are evolutionarily conserved proteins, and furthermore, that HSPs function not only during stress, but also during normal growth and development. My laboratory has characterized several of the major groups of HSPs in higher plants. We have cloned genes encoding plant HSP70 proteins and low molecular weight (LMW) HSPs (17-23 kDa). Using this information we have investigated the expression of HSPs both in the field, and under laboratory conditions which mimic field situations. We have determined the temperature limits for expression of HSPs in vegetative tissues, and have also found that HSPs are frequently produced in plant reproductive structures, even in the absence of stress. As a first step toward understanding HSP function, we have characterized the intracellular localization of HSPs. Results show that there are unique HSPs in the cytoplasm, chloroplast and endomembrane system. These ubiquitous proteins appear to play essential roles in many cellular processes.

scholarly journals Genome-Wide Analysis of AAT Genes and Their Expression Profiling during Fiber Development in Cotton

Plants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2461
Author(s):  
Dongjie Yang ◽  
Yuanyuan Liu ◽  
Hailiang Cheng ◽  
Qiaolian Wang ◽  
Limin Lv ◽  
...  
Keyword(s):  
Cotton Fiber ◽  
Biological Function ◽  
Higher Plants ◽  
Crop Improvement ◽  
Fiber Development ◽  
Maturity Stage ◽  
Amino Acid Transporters ◽  
Cotton Fiber Development ◽  
Fiber Initiation ◽  
Cotton Species

Amino acid transporters (AATs) are a kind of membrane proteins that mediate the transport of amino acids across cell membranes in higher plants. The AAT proteins are involved in regulating plant cell growth and various developmental processes. However, the biological function of this gene family in cotton fiber development is not clear. In this study, 190, 190, 101, and 94 full-length AAT genes were identified from Gossypiumhirsutum, G. barbadense, G. arboreum, and G. raimondii. A total of 575 AAT genes from the four cotton species were divided into two subfamilies and 12 clades based on phylogenetic analysis. The AAT genes in the four cotton species were distributed on all the chromosomes. All GhAAT genes contain multiple exons, and each GhAAT protein has multiple conserved motifs. Transcriptional profiling and RT qPCR analysis showed that four GhATT genes tend to express specifically at the fiber initiation stage. Eight genes tend to express specifically at the fiber elongation and maturity stage, and four genes tend to express specifically at the fiber initiation and elongation stages. Our results provide a solid basis for further elucidating the biological function of AAT genes related to cotton fiber development and offer valuable genetic resources for crop improvement in the future.

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