ABSTRACT
Tomato spotted wilt virus (TSWV) is ranked among the top 10 most destructive viruses globally. It results in abnormal leaf growth, stunting, and even death, significantly affecting crop yield and quality. Phytohormones play a crucial role in regulating plant-virus interactions. However, there is still limited research on the effect of TSWV on phytohormone levels, particularly growth hormones and genes involved in the phytohormone pathway. In our study, we combined phytohormone metabolomics and transcriptomics to examine the impact of TSWV infection on phytohormone content and gene expression profile. Metabolomic results showed that 41 metabolites, including major phytohormones and their precursors and derivatives were significantly altered after 14 days of TSWV inoculation tobacco plants cvK326, with 31 being significantly increased and 10 significantly reduced. Specifically, the levels of abscisic acid (ABA) and jasmonoyl-isoleucine (JA-Ile) were significantly reduced. The levels of indole-3-acetic acid (IAA) have remained unchanged. However, the levels of cytokinin isopentenyladenine (iP) and salicylic acid (SA) significantly increased. The transcriptome analysis revealed 2,746 genes with significant changes in expression. Out of these, 1,072 genes were significantly downregulated, while 1,674 genes were significantly upregulated. Among them, genes involved in ABA synthesis and signaling pathways, such as 9-cis-epoxycarotenoid dioxygenase (NCED), protein phosphatase 2C (PP2C), serine/threonine-protein kinase (SnRK2), and abscisic acid responsive element binding factor (ABF), exhibited significant downregulation. Additionally, expression of the lipoxygenase gene LOX, Jasmonate ZIM domain-containing protein gene JAZ, and transcription factor gene MYC were significantly down-regulated. In the cytokinin pathway, while there were no significant changes in the expression of the cytokinin synthesis genes, a significant downregulation of transcriptionally active factor type-B response regulators (type-B RRs) was observed. In terms of SA synthesis and signaling pathways, the isochorismate synthase gene ICS1 and the pathogenesis-related gene PR1 were significantly upregulated. These results can strengthen the theoretical foundation for understanding the interaction between TSWV and tobacco and provide new insights for the future prevention and control of TSWV.
Subject(s)
Plant Growth Regulators , Tospovirus , Nicotiana , Tospovirus/genetics , Abscisic Acid , Gene Expression Profiling , CytokininsABSTRACT
Herein, a novel sandwich surface plasmon resonance (SPR) detection assay, which utilizes prion disease-associated isoform (PrPSc) conjugating magnetic nanoparticle clusters (nanoparticle-organic clusters, NOCs) as signal amplification reagents, is constructed for the ultrasensitive detection of PrPSc. Due to the highly specific affinity of aptamer-Fe3O4 nanoparticles (AMNPs) toward PrPSc and the intermolecular assembly behaviors among PrPSc, PrPSc conjugating magnetic nanoparticle clusters were obtained after the incubation of AMNPs and PrPSc and the subsequent concentration processes in an external magnetic field. The conjugation clusters were further injected into the SPR cuvette and captured by the gold sensing film via the Au-S bonding interaction, inducing intense SPR responses. Meanwhile, a traditional sandwich SPR detection format using a gold/PrPSc/AMNPs amplification mode was conducted for the detection of PrPSc as comparison. The results reveal that the synthesized NOCs permitted a 215-fold increase of the SPR signal, while the sandwich format permitted only a 65-fold increase. Moreover, a lower detection limit (1 × 10-4 ng/mL) and a wider quantitation range (1 × 10-4-1 × 105 ng/mL) were demonstrated. The formation of the conjugation clusters and the capture of these clusters were confirmed by high-resolution AFM imaging and molecular simulations. This conjugation-cluster-induced signal amplification strategy has great potential for the detection of small analytes with similar structural characteristics in trace level concentrations with high selectivity and sensitivity by altering the corresponding aptamer labeled to magnetic particles.
ABSTRACT
Herein, we constructed a novel sandwich surface plasmon resonance (SPR) detection assay for sensitive prion disease-associated isoform (PrPSc) detection, utilizing bare gold film and apatamer-graphene oxide (AGO). Due to the self-assembling behavior of PrPSc on gold surface, the non-modified gold surface can be directly used as sensing surface for the quick detection, for the purpose to avoid the interference from the traditional, complex and changeable probe-modified sensing surface. And due to the highly specific affinity of AGO towards PrPSc, the sandwich type SPR sensor exhibits excellent analytical performance towards the discrimination and quantitation of PrPSc. A good linear relationship was obtained between SPR responses and the logarithm of PrPSc concentrations over a range of 0.001-1ng/mL. The detection sensitivity for PrPSc was improved by â¼156 orders of AGO compared with SPR direct detection format. Besides, morphological changes of the sensing film surfaces were investigated by high resolution AFM imaging, confirming the capture of PrPSc molecules and their further specific recognition by AGO. The specificity of the present biosensor was also investigated by PrPC and other regents as controls. By compared with other reported methods, the AGO enhanced sandwich SPR assay was confirmed to be efficient, sensitive, and with wide working range.
