Sandalwood (Santalum album L.) is famous for its unique fragrance derived from the essential oil of heartwood, whose major components are santalols. To understand the mechanism underlying the ...biosynthesis of santalols, in this study, we cloned two related genes involved in the mevalonate pathway in S. album coding for acetyl-CoA C-acetyl transferase (AACT) and 3-hydroxy-3-methyglutary-CoA synthase (HMGS). These genes were characterized and functionally analyzed, and their expression profiles were also assessed. An AACT gene designated as SaAACT (GenBank accession No. MH018694) and a HMGS gene designated as SaHMGS (GenBank accession No. MH018695) were successfully cloned from S. album. The deduced SaAACT and SaHMGS proteins contain 415 and 470 amino acids, and the corresponding size of their open-reading frames is 1538 bp and 1807 bp, respectively. Phylogenetic trees showed that the SaAACT protein had the closest relationship with AACT from Hevea brasiliensis and the SaHMGS proteins had the highest homology with HMGS from Siraitia grosvenorii. Functional complementation of SaAACT and SaHMGS in a mutant yeast strain deficient in these proteins confirmed that SaAACT and SaHMGS cDNA encodes functional SaAACT and SaHMGS that mediate mevalonate biosynthesis in yeast. Tissue-specific expression analysis revealed that both genes were constitutively expressed in all examined tissues (roots, sapwood, heartwood, young leaves, mature leaves and shoots) of S. album, both genes showing highest expression in roots. After S. album seedlings were treated with 100 μM methyl jasmonate, the expression levels of SaAACT and SaHMGS genes increased, suggesting that these genes were responsive to this elicitor. These studies provide insight that would allow further analysis of the role of genes related to the sandalwood mevalonate pathway in the regulation of biosynthesis of sandalwood terpenoids and a deeper understanding of the molecular mechanism of santalol biosynthesis.
Floral scent is a key ornamental trait that determines the quality and commercial value of orchids. Geraniol, an important volatile monoterpene in orchids that attracts pollinators, is also involved ...in responses to stresses but the geraniol synthase (GES) responsible for its synthesis in the medicinal orchid
has not yet been identified. In this study, three potential geraniol synthases were mined from the
genome. DoGES1, which was localized in chloroplasts, was characterized as a geraniol synthase.
was highly expressed in flowers, especially in petals.
transcript levels were high in the budding stage of
flowers at 11:00 a.m. DoGES1 catalyzed geraniol in vitro, and transient expression of
in
leaves resulted in the accumulation of geraniol in vivo. These findings on DoGES1 advance our understanding of geraniol biosynthesis in orchids, and lay the basis for genetic modification of floral scent in
or in other ornamental orchids.
Main conclusion
HDA704 enhances drought and salt tolerance via stomata-regulated mechanism. HDA704 negatively regulates stomatal aperture and density, repressing the transcription of DST and ABIL2 by ...histone deacetylation modification.
Drought and salinity can damage crop growth and reduce yield. Stomata play an important role in abiotic stress tolerance. In this study on rice, we identified the RPD3/HDA1-type histone deacetylase HDA704 as a positive regulatory factor in drought and salt tolerance.
HDA704
was induced by drought and salt stresses. Overexpression of
HDA704
in transgenic rice promoted stomatal closure, decreased the number of stomata and slowed down the rate of water loss, consequently resulting in increased drought and salt tolerance. By contrast, knockdown of
HDA704
in transgenic rice decreased stomatal closure and accelerated the rate of water loss, leading to decrease drought and salt tolerance. We detected the transcript expression of
DST
(
Drought and Salt Tolerance
) and
ABIL2
(
Abscisic Acid-insensitive Like2
), which positively regulate stomatal aperture and density in rice. Our results showed that HDA704 directly binds to
DST
and
ABIL2
, repressing their expression via histone deacetylation modification. Collectively, these findings reveal that HDA704 positively regulates drought and salt tolerance by repressing the expression of
DST
and
ABIL2
. Our findings provide a new insight into the molecular mechanisms of stomata-regulated abiotic stress tolerance of plants.
The COVID-19 pandemic, which has led to a flood of papers and preprints, has placed multiple challenges on academic publishing, the most obvious one being sustained integrity under the pressure to ...publish quickly. There are risks of this high volume-to-speed ratio. Many letters, editorials, and supposedly “peer reviewed” papers in ranked and indexed journals were published in a matter of days, suggesting that peer review was either fleeting or non-existential, or that papers were rapidly approved by editors based on their perceived interest and topicality, rather than on their intrinsic academic value. In academic publishing circles, the claim of “peer review”, when in fact it has not been conducted, is a core characteristic of “predatory publishing”, and is also a “fake” element that may undermine efforts in recent years to build trust in science's budding serials crisis. While the world is still centrally focused on COVID-19, the issue of “predatory publishing” is being ignored, or not being given sufficient attention. The risks to the scholarly community, academic publishing and ultimately public health are at stake when exploitative and predatory publishing are left unchallenged.
The SARS-CoV-2 virus, which causes Covid-19, induced a global pandemic for which an effective cure, either in the form of a drug or vaccine, has yet to be discovered. In the few brief months that the ...world has known Covid-19, there has been an unprecedented volume of papers published related to this disease, either in a bid to find solutions, or to discuss applied or related aspects. Data from Clarivate Analytics’ Web of Science, and Elsevier’s Scopus, which do not index preprints, were assessed. Our estimates indicate that 23,634 unique documents, 9960 of which were in common to both databases, were published between January 1 and June 30, 2020. Publications include research articles, letters, editorials, notes and reviews. As one example, amongst the 21,542 documents in Scopus, 47.6% were research articles, 22.4% were letters, and the rest were reviews, editorials, notes and other. Based on both databases, the top three countries, ranked by volume of published papers, are the USA, China, and Italy while
BMJ
,
Journal of Medical Virology
and
The Lancet
published the largest number of Covid-19-related papers. This paper provides one snapshot of how the publishing landscape has evolved in the first six months of 2020 in response to this pandemic and discusses the risks associated with the speed of publications.
Smoking Prevalence and COVID-19 in Europe Tsigaris, Panagiotis; Teixeira da Silva, Jaime A
Nicotine & tobacco research,
08/2020, Letnik:
22, Številka:
9
Journal Article
Recenzirano
Odprti dostop
Abstract
Introduction
This ecological study investigates the association between smoking prevalence and COVID-19 occurrence and mortality in 38 European nations as of May 30, 2020.
Methods
Data were ...collected from Our World in Data. Regression analysis was conducted to adjust for potential confounding factors such as economic activity (gross domestic product), the rate of COVID-19 testing, and the stringency of COVID-19 control policies.
Results
There was a statistically significant negative association between smoking prevalence and the prevalence of COVID-19 across the 38 European nations after controlling for confounding factors (p = 0.001). A strong association was found between the prevalence of COVID-19 per million people and economic activity (p = 0.002) and the rate of COVID-19 testing (p = 0.0006). Nations with stricter policy enactment showed fewer COVID-19 cases per million people, but the association was not significant (p = 0.122). Delaying policy enactment was associated with a greater prevalence of COVID-19 (p = 0.0535). Evidence of a direct association between smoking prevalence and COVID-19 mortality was not found (p = 0.626). There was a strong positive association between COVID-19 mortality rate and the prevalence of COVID-19 cases (p < 0.0001) as well as the proportion of the population over 65 years of age (p = 0.0034) and a negative association with the rate of COVID-19 testing (p = 0.0023).
Conclusions
We found a negative association between smoking prevalence and COVID-19 occurrence at the population level in 38 European countries. This association may not imply a true or causal relationship, and smoking is not advocated as a prevention or treatment of COVID-19.
Implications
Given the evidence of this ecological study, and of several other studies that found an underrepresentation of smoking prevalence in hospitalized cases, it may be worth examining, in laboratory experiments and controlled human trials, if nicotine offers any protection against COVID-19. Most importantly, to date, no study, including this one, supports the view that smoking acts as a treatment intervention or prophylaxis to reduce the impact or ameliorate the negative health impacts of COVID-19.
Terpene synthase (TPS) is a critical enzyme responsible for the biosynthesis of terpenes, which possess diverse roles in plant growth and development. Although many terpenes have been reported in ...orchids, limited information is available regarding the genome-wide identification and characterization of the TPS family in the orchid,
. By integrating the
genome and transcriptional data, 34
genes were found in
. These were divided into four subfamilies (TPS-a, TPS-b, TPS-c, and TPS-e/f). Distinct tempospatial expression profiles of
genes were observed in 10 organs of
. Most
genes were predominantly expressed in flowers, followed by roots and stems. Expression of the majority of
genes was enhanced following exposure to cold and osmotic stresses. Recombinant DoTPS10 protein, located in chloroplasts, uniquely converted geranyl diphosphate to linalool in vitro. The
gene, which resulted in linalool formation, was highly expressed during all flower developmental stages. Methyl jasmonate significantly up-regulated
expression and linalool accumulation. These results simultaneously provide valuable insight into understanding the roles of the TPS family and lay a basis for further studies on the regulation of terpenoid biosynthesis by
in
.
WRKY proteins are a large superfamily of transcription factors that are involved in diverse biological processes including development, as well as biotic and abiotic stress responses in plants. WRKY ...family proteins have been extensively characterized and analyzed in many plant species, including Arabidopsis, rice, and poplar. However, knowledge on WRKY transcription factors in
is scarce. Based on
genome and transcriptome data, 64
genes were identified in this study. A phylogenetic analysis based on the structures of WRKY protein sequences divided these genes into three major groups (I, II, III) together with WRKY protein sequences from Arabidopsis. Tissue-specific expression patterns showed that 37
genes were expressed in at least one of five tissues (leaves, roots, heartwood, sapwood, or the transition zone), while the remaining four genes weakly expressed in all of these tissues. Analysis of the expression profiles of the 42
genes after callus was initiated by salicylic acid (SA) and methyl jasmonate (MeJA) revealed that 25 and 24
genes, respectively, were significantly induced. The function of
, which was significantly up-regulated by SA and MeJA, was analyzed.
was localized in the nucleus and its overexpression improved salt tolerance in transgenic Arabidopsis. Our study provides important information to further identify the functions of
genes and to understand the roles of
family genes involved in the development and in SA- and MeJA-mediated stress responses.
Is ChatGPT a valid author? Teixeira da Silva, Jaime A.
Nurse education in practice,
March 2023, 2023-Mar, 2023-03-00, 20230301, Letnik:
68
Journal Article
Recenzirano
This letter to the editors takes a deeper look at the validity and ethics of authorship of a recently published article in Nurse Education in Practice in which authorship was shared with a chatbox ...software program, ChatGPT (https://doi.org/10.1016/j.nepr.2022.103537). In particular, a closer assessment is made of the authorship of that article from the established principles of authorship as delineated by the ICMJE.
Abstract
Sandalwood (
Santalum album
L.) is highly valued for its fragrant heartwood and extracted oil. Santalols, which are the main components of that oil, are terpenoids, and these are ...biosynthesized via the mevalonic acid (MVA) pathway. Mevalonate kinase (MK) and phosphomevalonate kinase (PMK) are key enzymes in the MVA pathway. Little is known about the genes that encode MK and PMK in
S. album
or the mechanism that regulates their expression. To isolate and identify the functional genes involved in santalol biosynthesis in
S. album
, an
MK
gene designated as
SaMK
, and a
PMK
gene designated as
SaPMK
, were cloned from
S. album
. The sequences of these genes were analyzed. A bioinformatics analysis was conducted to assess the homology of
SaMK
and
SaPMK
with
MK
and
PMK
genes from other plants. The subcellular localization of
SaMK
and
SaPMK
proteins was also investigated, as was the functional complementation of
SaMK
and
SaPMK
in yeast. Our results show that the full-length cDNA sequences of
SaMK
and
SaPMK
were 1409 bp and 1679 bp long, respectively.
SaMK
contained a 1381 bp open reading frame (ORF) encoding a polypeptide of 460 amino acids and
SaPMK
contained a 1527 bp ORF encoding a polypeptide of 508 amino acids.
SaMK
and
SaPMK
showed high homology with
MK
and
PMK
genes of other plant species. Functional complementation of
SaMK
in a MK-deficient mutant yeast strain YMR208W and
SaPMK
in a PMK-deficient mutant yeast strain YMR220W confirmed that cloned
SaMK
and
SaPMK
cDNA encode a functional MK and PMK, respectively, mediating MVA biosynthesis in yeast. An analysis of tissue expression patterns revealed that
SaMK
and
SaPMK
were constitutively expressed in all the tested tissues.
SaMK
was highly expressed in young leaves but weakly expressed in sapwood.
SaPMK
was highly expressed in roots and mature leaves, but weakly expressed in young leaves. Induction experiments with several elicitors showed that
SaMK
and
SaPMK
expression was upregulated by methyl jasmonate. These results will help to further study the role of
MK
and
PMK
genes during santalol biosynthesis in
S. album
.
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