Project description:Leukemia is a blood or bone marrow cancer with increasing incidence in developed regions of the world. Currently, there is an ongoing need for novel and safe anti-leukemic agents, as no fully effective chemotherapy is available to treat this life-threatening disease. Herein, are reported the isolation, structural elucidation, and anti-leukemic evaluation of twenty-nine withanolide-type steroids (1-29) from Withania aristata. Among them, the new isolated withanolides, withaperoxidins A-D (1-4) have an unusual six-membered cyclic peroxide moiety on the withasteroid skeleton as a structural novelty. Their structures have been elucidated by means of spectroscopic analyses, including 2D NMR experiments. In addition, extensive structure-activity relationships and in silico ADME studies were employed to understand the pharmacophore and pharmacokinetic properties of this series of withasteroids. Compounds 15, 16, and 22 together with withaferin A (14) were identified as having improved antiproliferative effect (IC50 ranging from 0.2 to 0.7 μM) on human leukemia HL-60 cell lines compared with the reference drug, etoposide. This cytotoxic potency was also coupled with good selectivity index (SI 33.0-9.2) on non-tumoral Vero cell line and in silico drug likeness. These findings revealed that these natural withasteroids are potential candidates as chemotherapeutic agents in the treatment of leukemia.
Project description:Gelechioidea represents the most diverse superfamily of tiny boring pests in Lepidoptera that pose a serious threat to agricultural and forestry economic crops. However, the lack of high-quality genome of highly specialized species makes it difficult to draw general conclusions about the mechanism of the close binding relationship between pests and crops. In this study, based on second- and third-generation sequencing reads, we constructed a chromosome-level genome for the Atrijuglans aristata, a specialized boring pest, that specifically harms the green husk of cultivated walnuts. The genome is 480.99 Mb and spans 31 pseudo-chromosomes, including Z and a portion of W chromosome. Contig N50 and scaffold N50 of the genome are 2.68 Mb and 16.01 Mb respectively. The BUSCO completeness achieves 95.6% with a total of 22,542 protein-coding genes are annotated. As the first sequenced genome of Stathmopodidae family, this high-quality genome provides a genetic basis for the mining of genes for important functional traits in A. aristata, as well as an important reference for the study of host adaptation of the (insect) specialists.
Project description:Flower opening is important for successful pollination in many plant species, and some species repeat reversible flower opening and closing movements. This is thought to be due to the turgor pressure change caused by the water influx/efflux, which depends on osmotic oscillation in the cells. In some ornamental plants, it has been suggested that water channel aquaporin may play an important role in flower opening. However, the molecular mechanism(s) involved in flower movement are largely unknown. Using Gentiana flowers, which show reversible movement in response to temperature and light stimuli, as a model, we showed that reversible flower opening is regulated by aquaporin GsPIP2;2 and GsPIP2;7. In particular, phosphorylation of the C-terminal serine residue of GsPIP2;2 is important for the transport activity and correlates closely with the flower re-opening rate. Furthermore, GsPIP2;2 is phosphorylated and activated by GsCPK16, which is activated by elevated cytosolic Ca2+ levels in response to temperature and light stimuli. We propose that reversible flower opening is regulated by GsCPK16-dependent GsPIP2;2 phosphorylation and activation, with stimulus-induced calcium signals acting as triggers. CPK-dependent phosphorylation and activation of PIP2s may be one of the universal regulatory mechanisms for flower opening in plants.
Project description:Many recent studies have suggested that the majority of animal-pollinated plants have a higher diversity of pollinators than that expected according to their pollination syndrome. This broad generalization, often based on pollination web data, has been challenged by the fact that some floral visitors recorded in pollination webs are ineffective pollinators. To contribute to this debate, and to obtain a contrast between visitors and pollinators, we studied insect and bird visitors to virgin flowers of Hypoestes aristata in the Bamenda Highlands, Cameroon. We observed the flowers and their visitors for 2-h periods and measured the seed production as a metric of reproductive success. We determined the effects of individual visitors using 2 statistical models, single-visit data that were gathered for more frequent visitor species, and frequency data. This approach enabled us to determine the positive as well as neutral or negative impact of visitors on H. aristata's reproductive success. We found that (i) this plant is not generalized but rather specialized; although we recorded 15 morphotaxa of visitors, only 3 large bee species seemed to be important pollinators; (ii) the carpenter bee Xylocopa cf. inconstans was both the most frequent and the most effective pollinator; (iii) the honey bee Apis mellifera acted as a nectar thief with apparent negative effects on the plant reproduction; and (iv) the close relationship between H. aristata and carpenter bees was in agreement with the large-bee pollination syndrome of this plant. Our results highlight the need for studies detecting the roles of individual visitors. We showed that such an approach is necessary to evaluate the pollination syndrome hypothesis and create relevant evolutionary and ecological hypotheses.
Project description:BackgroundFloating bamboo (Hygroryza aristata) is an endangered species with a narrow native distribution and is renowned for its unique aesthetic qualities, which holds significant ecological and ornamental value. However, the lack of genetic information research, with only one complete plastome available, significantly hampers conservation efforts and further research for this species.ResultsIn this research, we sequenced and assembled the organelle genomes of floating bamboo, including the mitogenome (587,847 bp) and plastome (135,675 bp). The mitogenome can recombine into various configurations, which are mediated by 25 repeat pairs (13 SRs, 6 MRs, 1 LR, and 5 CRs). LR1 and SR5 are particularly notable as they have the ability to combine with other contigs, forming complex repeat units that facilitate further homologous recombination. The rate of homologous recombination varies significantly among species, yet there is still a pronounced positive correlation observed between the length of these repeat pairs and the rate of recombination they mediate. The mitogenome integrates seven intact protein-coding genes from the chloroplast. The codon usage patterns in both organelles are similar, with a noticeable bias towards C and T on the third codon. The gene map of Poales shows the entire loss of rpl6, succinate dehydrogenase subunits (sdh3 and sdh4). Additionally, the BOP clade retained more variable genes compared to the PACMAD clade.ConclusionsWe provided a high-quality and well-annotated mitogenome for floating bamboo and demonstrated the presence of diverse configurations. Our study has revealed the correlation between repeat length and their corresponding recombination rate despite variations among species. Although the mitogenome can potentially exist in the form of a unicircular in vivo, this occurrence is rare and may not be stable.
Project description:Characterization of the activities of the transcription factor that AG encodes throughout flower development using perturbation assays and ChIP-Seq in combination with a floral induction system (FIS) that allows a stage-specific analysis of flower development.