In Situ Growth of Plasmonic Gold Nanoparticles for the Direct and Sensitive Colorimetric Assay of Glucose

Shaohuang Weng,Feng Feng,Honghui Guo,Namei Wu,Yanjie Zheng,Zhen Lin,Xinhua Lin 대한화학회 2017 Bulletin of the Korean Chemical Society Vol.38 No.3

Gold nanoparticles (Au NPs)-based colorimetric assay for the highly sensitive and selective detection of glucose has been conducted. The sensing, which was based on the in situ growth of Au NPs in the presence of glucose, was developed with the solution changing from colorless to red. This change could be observed with the naked eye or a ultraviolet–visible (UV–vis) spectrophotometer. Moreover, adding trace amounts of Tween-20 kept Au NPs well spaced. Under the optimal assay conditions, the absorbance of Au NPs at 550 nm was proportional to glucose concentration within 400–1800 μM with a linear regression equation, and the detection limit was 6.28 μM. Some common interfering compounds in beverages, including other sugars, food additives, and amino acids, did not affect glucose sensing. Therefore, the proposed Au NP-based colorimetric assay could be successfully used to determine glucose in beverages.

Temperature dependent defence of Nicotiana tabacum against Cucumber mosaic virus and recovery occurs with the formation of dark green islands

Feifei Zhao,Yanan Li,Li-juan Chen,Lisha Zhu,Han Ren,Honghui Lin,Dehui Xi 한국식물학회 2016 Journal of Plant Biology Vol.59 No.3

Temperature is an important environmental factor controlling plant growth, development, and immune response. However, the role of temperature in plant disease resistance is still elusive. In the present study, the potential effects of temperature on the interaction between Nicotiana tabacum and Cucumber mosaic virus (CMV) were investigated. Our results indicated that N. tabacum plants displayed severe symptoms at early stage of post inoculation at high temperature (HT, 28°C), associated with higher viral replication level, more serious stress damages. By contrast, low temperature (LT, 18°C) effectively delayed the replication of CMV compared with elevated temperatures. Additionally, quantitative real-time PCR analyses revealed that lower temperatures (≤ 24°C) promote salicylic acid (SA) dependent responses, whereas higher temperatures (> 24°C) activate the genes expression of jasmonic acid (JA) pathway. Interestingly, the dark green islands (DGIs) appeared much earlier in CMV-inoculated plants grown at HT compared with those at LT and the accumulation of virus small interfering RNAs in plants were significantly up-regulated under elevated temperatures at early stage of post inoculation. Taken together, these results indicated that temperature changes had important effects on plant defence response, and different temperatures could induce different immune pathways of N. tabacum against CMV infection.

Application of Jasmonic Acid Followed by Salicylic Acid Inhibits Cucumber mosaic virus Replication

Luo, Ying,Shang, Jing,Zhao, Pingping,Xi, Dehui,Yuan, Shu,Lin, Honghui The Korean Society of Plant Pathology 2011 Plant Pathology Journal Vol.27 No.1

Systemic acquired resistance is a form of inducible resistance that is triggered in systemic healthy tissues of local-infected plants. Several candidate signaling molecules emerged in the past two years, including the methylated derivatives of well-known defense hormones salicylic acid (SA) and jasmonic acid (JA). In our present study, the symptom on Cucumber mosaic virus (CMV) infected Arabidopsis leaves in 0.1 mM SA or 0.06 mM JA pre-treated plants was lighter (less reactive oxygen species accumulation and less oxidative damages) than that of the control group. JA followed by SA (JA${\rightarrow}$SA) had the highest inhibitory efficiency to CMV replication, higher than JA and SA simultaneous co-pretreatment (JA+SA), and higher than a JA or a SA single pretreatment. The crosstalk between the two hormones was further investigated at the transcriptional levels of pathogenesis-related genes. The time-course measurement showed JA might play a more important role in the interaction between JA and SA.

Application of Jasmonic Acid Followed by Salicylic Acid Inhibits Cucumber mosaic virus Replication

Ying Luo,Jing Shang,Pingping Zhao,Dehui Xi,Shu Yuan,Honghui Lin 한국식물병리학회 2011 Plant Pathology Journal Vol.27 No.1

Systemic acquired resistance is a form of inducible resistance that is triggered in systemic healthy tissues of local-infected plants. Several candidate signaling molecules emerged in the past two years, including the methylated derivatives of well-known defense hormones salicylic acid (SA) and jasmonic acid (JA). In our present study, the symptom on Cucumber mosaic virus (CMV) infected Arabidopsis leaves in 0.1 mM SA or 0.06 mM JA pre-treated plants was lighter (less reactive oxygen species accumulation and less oxidative damages)than that of the control group. JA followed by SA (JA→SA) had the highest inhibitory efficiency to CMV replication, higher than JA and SA simultaneous co-pretreatment (JA+SA), and higher than a JA or a SA single pretreatment. The crosstalk between the two hormones was further investigated at the transcriptional levels of pathogenesis-related genes. The time-course measurement showed JA might play a more important role in the interaction between JA and SA.

Proanthocyanidins accelerate the germination of cucumber (Cucumis sativus L.) seeds

Li-jun Zhu,Xing-guang Deng,Li-juan Zou,Jun-qiang Wu,Da-wei Zhang,Honghui Lin 한국식물학회 2016 Journal of Plant Biology Vol.59 No.2

Proanthocyanidins (PAs) are the end products of the flavonoid biosynthetic pathway in many seeds, but their biological function is rarely unknown during seed germination. In the present study, we observed that PAs pretreatment accelerated cucumber seeds germination with maximum efficiency at 0.15% by measuring germination percentage and radical length. Using inhibitors of abscisic acid (ABA), gibberellins (GA) and alternative oxidase (AOX) and H2O2 scavenger pretreatment and gene expression analysis, we found that the accelerated effect of 0.15% PAs on seed germination was due to the decreased ABA biogenesis and enhanced GA production. ROS are induced by PAs pretreatment. Then, the enhanced ROS contributed to GA and ethylene accumulation and ABA decrease in seeds. Moreover, the improvement of GA was involved in the further induction of antioxidant enzymes activities. Therefore, our findings uncover a novel role of PAs in seed germination and clarify the relationships between ROS, ABA, GA and ethylene during seed germination.

Celastrol, produced by Tripterygium wilfordii Hook F. enhances defense response in cucumber seedlings against diverse environmental stresses

Li-jun Zhu,Xing-guang Deng,Li-juan Zou,Peng-xu Li,Jun-qiang Wu,Da-wei Zhang,Honghui Lin 한국식물학회 2017 Journal of Plant Biology Vol.60 No.1

Celastrol is an active triterpenoid compound isolated from Tripterygium wilfordii Hook F.. Many reports have highlighted that celastrol is an effective, safe and desirable approach to the treatment of cancers. However, their biological function during environmental stresses in plants is rarely reported. In the present study, the effects of celastrol on the tolerance against high light (HL), polyethylene glycol (PEG) and cold stress in cucumber (Cucumis sativus L.) were investigated. Celastrol pretreatment could enhance cucumber seedlings stress tolerance at a concentration of 1 μg ml–1. The results showed that pretreatment with 1 μg ml–1 celastrol clearly induced the activities of antioxidative enzymes, which subsequently alleviated stress-induced oxidative damage in plant cells. We also provided evidence that celastrol upregulated ABA biosynthetic gene NCED2 expression and ABA accumulation in cucumber seedlings, which resulted to the enhanced tolerance in response to environmental stresses. Furthermore, the celastrol-pretreated seedlings showed less photosystem damaged caused by the stress conditions, when compared with the control. Therefore, our findings provide a novel role of celastrol in plant against environmental stresses and indicate that the celastrol-induced activities of antioxidative enzymes and ABA content might contribute to the stress tolerance.

Host Langerin (CD207) is a receptor for <i>Yersinia pestis</i> phagocytosis and promotes dissemination

Yang, Kun,Park, Chae G,Cheong, Cheolho,Bulgheresi, Silvia,Zhang, Shusheng,Zhang, Pei,He, Yingxia,Jiang, Lingyu,Huang, Hongping,Ding, Honghui,Wu, Yiping,Wang, Shaogang,Zhang, Lin,Li, Anyi,Xia, Lianxu,B Nature Publishing Group 2015 Immunology and Cell Biology Vol. No.

<P><I>Yersinia pestis</I> is a Gram‐negative bacterium that causes plague. After <I>Y. pestis</I> overcomes the skin barrier, it encounters antigen‐presenting cells (APCs), such as Langerhans and dendritic cells. They transport the bacteria from the skin to the lymph nodes. However, the molecular mechanisms involved in bacterial transmission are unclear. Langerhans cells (LCs) express Langerin (CD207), a calcium‐dependent (C‐type) lectin. Furthermore, <I>Y. pestis</I> possesses exposed core oligosaccharides. In this study, we show that <I>Y. pestis</I> invades LCs and Langerin‐expressing transfectants. However, when the bacterial core oligosaccharides are shielded or truncated, <I>Y. pestis</I> propensity to invade Langerhans and Langerin‐expressing cells decreases. Moreover, the interaction of <I>Y. pestis</I> with Langerin‐expressing transfectants is inhibited by purified Langerin, a DC‐SIGN (DC‐specific intercellular adhesion molecule 3 grabbing nonintegrin)‐like molecule, an anti‐CD207 antibody, purified core oligosaccharides and several oligosaccharides. Furthermore, covering core oligosaccharides reduces the mortality associated with murine infection by adversely affecting the transmission of <I>Y. pestis</I> to lymph nodes. These results demonstrate that direct interaction of core oligosaccharides with Langerin facilitates the invasion of LCs by <I>Y. pestis</I>. Therefore, Langerin‐mediated binding of <I>Y. pestis</I> to APCs may promote its dissemination and infection.</P>