Terahertz technology and its applications in head and neck diseases

Summary: The terahertz (THz) radiation refers to electromagnetic waves between infrared and millimeter waves. THz technology has shown a significant potential for medical diagnosis and biomedical applications over the past three decades. Therefore, exploring the biological effects of THz waves has become an important new field in life sciences. Specifically, THz radiation has been proved to be able to diagnose and treat several head and neck diseases. In this review, we primarily discuss the biological characteristics of THz waves and clinical applications of THz technology, focusing on the research progress of THz technology in head and neck diseases (brain cancer, hypopharyngeal cancer, oral diseases, thyroid nodules, Alzheimer’s disease, eyes diseases, and otitis). The future application perspectives of THz technologies in head and neck diseases are also highlighted and proposed

The Hv-SGT1 gene from Haynaldia villosa contributes to resistances towards both biotrophic and hemi-biotrophic pathogens in common wheat (Triticum aestivum L.).

The SGT1 protein is essential for R protein-mediated and PAMPs-triggered resistance in many plant species. Here we reported the isolation and characterization of the Hv-SGT1 gene from Haynaldiavillosa (2n = 14, VV). Analysis of the subcellular location of Hv-SGT1 by transient expression of a fusion to GFP indicated its presence in the cytoplasm and nucleus. Levels of Hv-SGT1 transcripts were increased by inoculation with either the biotrophic pathogen Blumeriagraminis DC. f. Sp. tritici (Bgt) or the hemi-biotrophic pathogen Fusariumgraminearum (Fg). Levels of Hv-SGT1 showed substantial increase following treatment with H2O2 and methyl jasmonate (MeJA), only slightly induced following exposure to ethephon or abscisic acid, but not changed following exposure to salicylic acid. The demonstration that silencing of Hv-SGT1 substantially reduced resistance to Bgt indicated that Hv-SGT1 was an essential component of disease resistance in H. villosa. The over-expression of Hv-SGT1 in Yangmai 158 enhanced resistance to powdery mildew, and this correlated with increased levels of whole-cell reactive oxygen intermediates at the sites of penetration by the pathogens. Compared with wild-type plants, the expression levels of genes related to the H2O2 and JA signaling pathways were lower in the Hv-SGT1 silenced plants and higher in the Hv-SGT1 over-expressing plants. Therefore, the involvement of Hv-SGT1 in H2O2 production correlates with the hypersensitive response and jasmonic acid signaling. Our novel demonstration that wheat with over-expressed Hv-SGT1 showed enhanced resistance to both powdery mildew and FHB suggests that it could served as a transgenic genetic resource in wheat breeding for multiple disease resistance

Hydrogen peroxide accumulation in leaves of <i>Hv-SGT1</i> over-expressing plants and the WT Yangmai 158.

<p>Hydrogen peroxide accumulated in Yangmai 158 (A), and <i>Hv-SGT1</i> over-expressing lines OX-323 (B) and OX-330 (C). (D) Whole-cell ROI accumulation. (E) Oxidative burst at the <i>Bgt</i> interaction site. (F) Comparison of the percentage of cells with H₂O₂ accumulation throughout the entire cell or only around the infection sites in wild-type Yangmai 158 and the transgenic plants (* means p < 0.05).</p

Relative expression levels of <i>Ta-SGT1</i> in spikes of scab-resistant wheat variety Wangshuibai (WSB) and its susceptible mutant NAUH117 at different times after inoculation with <i>Fg</i>.

<p>(A) <i>Ta-SGT1</i> was constitutively expressed in both WSB and NAUH117, and no obvious change was detected after inoculation with <i>Fg</i>. Nonetheless, an approximately 6-fold lower expression level of <i>Ta-SGT1</i> transcript was detected in the susceptible mutant NAUH117 than that in resistant WSB. (B) The FHB symptom of spikes of Yangmai158 and transgenic plants at 21 days after <i>Fusarium</i> inoculation, scale bar represents 1cm.</p

Responses of <i>SGT1</i> to treatments of biotic and abiotic stresses, as well as phytohormone applications.

<p>Expression patterns of <i>SGT1</i> (A) in different organs of <i>H</i><i>. villosa</i>, (B) in <i>H</i><i>. villosa</i> leaves after <i>Bgt</i> inoculation, (C) in <i>H</i><i>. villosa</i> immature spikes after <i>Fg</i> inoculation, and (D) in <i>H</i><i>. villosa</i> leaves fter treatments with ET, ABA, SA, MeJA, and H₂O₂.</p

Real-time qPCR analysis of the expression patterns of ten genes related to pathogenesis pathway in the wild-type Yangmai 158 and <i>Hv-SGT1-</i>over-expressing transgenic plants (OX-323) before inoculation of <i>Bgt</i> and 24 h post inoculation with <i>Bgt</i>.

<p>* p < 0.05, ** p < 0.01 compared with the wild type. Over-expression <i>Hv-SGT1</i> regulates the expression of genes related to the H₂O₂, SA and JA pathways.</p

Analysis of primary structure and conserved domains of SGT1 proteins.

<p>(A) Sequence alignment analysis and the predicted conserved domains of SGT1 proteins. GenBank accession numbers: Rice (AAF18438), Wheat (EF546432.1), <i>Arabidopsis</i> (AF439975, AF439976), Barley (AF439974). The black (100%), pink (80%), and blue (60%) boxes represent levels of amino acid identity or similarity. The conserved domains were underlined. (B) The phylogenetic analysis of the amino acid sequence of <i>SGT1</i> genes from different species. GenBank accession numbers: OsSGT1 (AAF18438), TaSGT1 (ABQ23992.1), TaSGT1-1 (ABO18602.1), TaSGT1-2 (ABO18603.1), HHvSGT1-Barley (AF439974), BdSGT1 (XP_003569394.1), SbSGT1 (EES01101.1), Zm-SGT1 (ACG34278.1), NbSGT1 (AAW82048.1), AtSGT1a (AF439975) and AtSGT1b (AF439976). The tree was generated by ClustalX1.83 analysis with the corrected full-length Hv-SGT1 protein sequences using Neighbor-Joining method (MEGA4.0 software). The bar beneath the dendrogram represents a distance of 0.05 change per amino acid.</p

Characterization of the transgenic wheat of <i>Hv-SGT1</i>.

<p>(A) PCR and PCR-Southern blot of four transgenic lines that over-expressing <i>Hv-SGT1</i> (OX), and the non-transformed control Yangmai 158. The plasmid <i>pBI220.6-Hv-SGT1</i> and Yangmai 158 were used as the positive and negative controls, respectively. (B) qRT-PCR of the expression of <i>Hv-SGT1</i> in the four transgenic lines and Yangmai 158. ** p < 0.01 compared with the control. (C) Reduced disease symptoms in transgenic plants. Seedling resistance of transgenic line or wild-type plants was assessed following <i>in vitro</i> infection with the native pathogen population (Sumai 3). (D) Microscopic observation of <i>Bgt</i> hyphae spreading after DioC6 staining of the transgenic plants and Yangmai 158. (E) Quantitative comparisons of the percentage of infection sites with secondary hyphae (SH), the average number of hyphal branches and average hyphal length emerging on the leaves of infection sites. Means (± SE) were calculated using the measurements from five seedlings, and at least 30 infection sites for each seedling. Significance was determined according to paired sample <i>t</i>-test method (b indicates <i>P</i> < 0.05).</p

Subcellular localization of Hv-SGT1-GFP fusion protein by transient expression via biolistic bombardment.

<p>(A–B) Detected GFP under blue emitting light (nucleus stainning with DAPI) and visible light (merged), and green emitting light of the onion epidermis cell and (E) in the merged figure of the <i>H</i><i>. villosa</i> epidermis cell, indicating that GFP was sub-celluarly located to the whole cell. (C–D) Detected Hv-SGT1-GFP under blue emitting light (nucleus stainning with DAPI) and visible light (merged), and green emitting light of the onion epidermis cell and (F) in the merged figure of the <i>H</i><i>. villosa</i> epidermis cell, indicating that the Hv-SGT1 was subcelluarly located to the nuclei and cytoplasm.</p