Biology subjects

Nguyen, T. T. N.

Publications and source records attributed to Nguyen, T. T. N..

4 recordsLinked to original sources

bioRxiv2026

Evaluating cacao pod resistance to black pod disease caused by three Phytophthora species

Black pod disease is a major threat to global cacao (Theobroma cacao L.) production. It is caused by multiple Phytophthora species with geographic ranges from regionally restricted to pantropical, and developing resistant cultivars requires screening against the diversity of these pathogens. This study evaluated the response of 25 cacao clones to 13 isolates of P. palmivora (eight), P. megakarya (two), and P. theobromicola (three) by nonwounding inoculation of detached pods. Lesion size and lesion expansion status were evaluated 4 days after inoculation. The linear mixed model included 178 combinations among 17 clones and 12 isolates, each represented by at least two biological replicate pods. Lesion size differed among clones (F(16, 449.2) = 25.16) and among isolates (F(11, 416.0) = 32.90), and the clone by isolate interaction was significant (F(150, 465.4) = 1.72; all P < 0.001). PENTAGONA-17 had the smallest estimated marginal lesion size (9.3 mm) and fitted values of 3.8 to 16.9 mm across 11 isolates representing all three species. ARF-31, ICS-47, POUND-7, and PMCT-73 had the next four smallest estimates, whereas NA-246 had the largest (36.7 mm). Isolate estimates varied more than fourfold, from 9.6 to 42.0 mm. Despite a marginal estimate of 12.9 mm, POUND-7 had a fitted estimate of 49.2 mm with P. megakarya GH34. The probability of lesion expansion also differed among clones and isolates (both P < 0.001). Together, these findings identify candidates for further resistance evaluation and show that multi-isolate screening provides a stronger basis for selecting materials for black pod resistance breeding.

plant biology↗

bioRxiv2023

polo affects cell fate upon ionizing radiation in Drosophila hematopoietic progenitors by negatively regulating lok

In response to ionizing radiation (IR), stem cells undergo cell cycle arrest, senescence, premature differentiation, or cell death. The decision between survival and death is critical during tumorigenesis and effective killing of cancer cells. We used the larval Drosophila lymph gland, a hematopoietic organ, as a model to understand the mechanism for cell fate decisions during stem cell development. The hematopoietic progenitors survived or died via apoptosis when larvae were irradiated in early or late third instar larval (L3) stages, respectively. In late L3 progenitors, the basal level of polo (Drosophila PLK1) was low, enabling IR-induced activation of lok (Drosophila CHK2), which was necessary and sufficient for inducing autophagy and reactive oxygen species (ROS) production resulting in cell death. The high level of polo in early L3 progenitors negatively regulated lok resulting in significantly low or undetectable levels of ROS or autophagy, respectively. The surviving early L3 progenitors underwent cell cycle arrest followed by premature differentiation affected by tefu (Drosophila ATM) and lok mutation. These results provide clues for designing effective therapeutic strategies for cancer. Summary statementWe elucidated the mechanism underlying cell fate decisions during stem cell development in larval Drosophila, which will help develop effective cancer treatment modalities.

developmental biology↗

bioRxiv2023

Influences of chemotype and parental genotype on metabolic fingerprints of tansy plants uncovered by predictive metabolomics.

Intraspecific plant chemodiversity shapes plant-environment interactions. Within species, chemotypes can be defined according to variation in dominant specialised metabolites belonging to certain classes. Different ecological functions could be assigned to these distinct chemotypes. However, the roles of other metabolic variations and the parental genotype of the chemotypes remain poorly explored. Here, we first compared the capacity of terpenoid profiles and metabolic fingerprints to distinguish five chemotypes of common tansy (Tanacetum vulgare) and depict satellite metabolic differences. Metabolic fingerprints captured higher satellite variation while preserving the ability to define chemotypes. These satellite differences might influence plant performance and interactions with the environment. Next, to characterise the influence of the maternal genotype on chemodiversity, we performed variation partitioning and generalised linear modelling. Our findings revealed that maternal genotype was a higher source of chemical variation than chemotype. Predictive metabolomics unveiled 184 markers predicting maternal genotype with 89% accuracy. These markers included, among others, phenolics, whose functions in plant-environment interactions are well established. Hence, these findings place parental genotype at the forefront of intraspecific chemodiversity. We thus recommend considering this factor when comparing the ecology of various chemotypes. Besides, the combined inclusion of inherited and satellite metabolic variation in computational models may help connecting chemodiversity and evolutionary principles.

ecology↗

bioRxiv2020

WHOLE-GENOME SEQUENCING AND DE NOVO ASSEMBLY OF A 2019 NOVEL CORONAVIRUS (SARS-COV-2) STRAIN ISOLATED IN VIETNAM

The pandemic COVID-19 caused by the zoonotic virus SARS-CoV-2 has devastated countries worldwide, infecting more than 4.5 million people and leading to more than 300,000 deaths. Whole genome sequencing (WGS) is an effective tool to monitor emerging strains and provide information for intervention, thus help to inform outbreak control decisions. Here, we reported the first effort to sequence and de novo assemble the whole genome of SARS-CoV-2 using PacBios SMRT sequencing technology in Vietnam. We also presented the annotation results and a brief analysis of the variants found in our SARS-CoV-2 strain, which was isolated from a Vietnamese patient. The sequencing was successfully completed and de novo assembled in less than 30 hours, resulting in one contig with no gap and a length of 29,766 bp. All detected variants as compared to the NCBI reference were highly accurate as confirmed by Sanger sequencing. The results have shown the potential of long read sequencing to provide high quality WGS data to support public health responses, and advance understanding of this and future pandemics.

genomics↗