Duckweeds are among the fastest reproducing plants, able to clonally divide at exponential rates. However, the genetic and epigenetic impact of clonality on plant genomes is poorly understood. 5-methylcytosine (5mC) is a modified base often described as necessary for the proper regulation of certain genes and transposons and for the maintenance of genome integrity in plants. However, the extent of this dogma is limited by the current phylogenetic sampling of land plant species diversity. Here we analyzed DNA methylomes, small RNAs, mRNA-seq, and H3K9me2 histone modification for Spirodela polyrhiza. S. polyrhiza has lost highly conserved genes involved in de novo methylation of DNA at sites often associated with repetitive DNA, and within genes, however, symmetrical DNA methylation and heterochromatin are maintained during cell division at certain transposons and repeats. Consequently, small RNAs that normally guide methylation to silence repetitive DNA like retrotransposons are diminished. Despite the loss of a highly conserved methylation pathway, and the reduction of small RNAs that normally target repetitive DNA, transposons have not proliferated in the genome, perhaps due in part to the rapid, clonal growth lifestyle of duckweeds.
Cells use DNA photolyases to protect their DNA from the damaging effects of UV radiation. Marine cyanobacteria possess many genes that appear to encode photolyases, but the function of the proteins encoded by these genes is unclear.
more » « less- Award ID(s):
- 1818187
- PAR ID:
- 10475002
- Editor(s):
- Ruby, Edward
- Publisher / Repository:
- American Society for Microbiology
- Date Published:
- Journal Name:
- mBio
- Volume:
- 13
- Issue:
- 4
- ISSN:
- 2150-7511
- Subject(s) / Keyword(s):
- DNA photolyase, Synechococcus, UV light, cyanobacteria, marine microbiology
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Abstract -
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Microplitis demolitor bracovirus (MdBV) virions recently identified 16 genes encoding nucleocapsid components. In this study, we further characterized most of these genes. Some nucleocapsid genes exhibited early or intermediate expression profiles, while others exhibited late expression profiles. RNA interference (RNAi) assays together with transmission electron microscopy indicatedvp39 ,HzNVorf9-like2 ,HzNVorf93-like ,HzNVorf106-like ,HzNVorf118-like ,and 27b are required to produce capsids with a normal barrel-shaped morphology. RNAi knockdown ofvlf-1a ,vlf-1b-1 ,vlf-1b-2 ,int-1, andp6.9-1 did not alter the formation of barrel-shaped capsids but each reduced processing of amplified proviral segments and DNA packaging as evidenced by the formation of electron translucent capsids. All of the genes required for normal capsid assembly were also required for proviral segment processing and DNA packaging. Collectively, our results deorphanize several BV genes with previously unknown roles in virion morphogenesis.IMPORTANCE Understanding how bracoviruses (BVs) function in wasps is of broad interest in the study of virus evolution. This study characterizes most of the
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Thinopyrum intermedium (an emerging perennial cereal) and in wheat and barley under intermittent freezing stress and under nonfreezing conditions. Activity of glutathione peroxidase (GPX) and four other antioxidative enzymes was also measured under these conditions. DNA repair genes included photolyases involved in repairing ultraviolet‐induced damage and two genes involved in repairing oxidatively induced damage (ERCC1, RAD23 ).RESULTS Freezing stress was accompanied by large increases in photolyase expression and
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1128/mbio.01511-22
