Dynamics of Yeast-like Symbiote and Its Relationship with the Virulence of Brown Planthopper, Nilaparvata lugens Stal, to Resistant Rice Varieties

Lu, Zhong-Xian,Yu, Xiao-Ping,Chen, Jian-Ming,Zheng, Xu-Song,Xu, Hong-Xing,Zhang, Jue-Feng,Chen, Lie-Zhong Korean Society of Applied Entomology 2004 Journal of Asia-Pacific Entomology Vol.7 No.3

Abundance of the yeast-like symbiote (YLS) in brown planthopper (BPH), Nilaparvata lugens Stal, collected from rice fields in China and obtained from International Rice Research Institute (IRRI), was monitored. The role of YLS in nymph survival rate, development and adult reproduction, and activities of transaminases in BPH on different resistant rice varieties were examined. Also, the relationship between YLS and virulence shifts of BPH to resistant rice varieties was discussed. The results indicated that the virulence of BPH populations to resistant rice varieties was strongly related to the abundance of YLS in 5th instar nymphs and brachypterous females of BPH field populations at Nanning in South China and Hangzhou m East China, showing the more abundance of YLS in BPH, the higher virulence of BPH to resistant rice varieties, while no obvious differences in YLS abundance were monitored between three BPH biotypes. Numbers of YLS reduced significantly in female adult of BPH biotype 1 fed on resistant rice varieties IR26, Mudgo and ASD7, compared with that fed on susceptible rice variety TN1. The lowest YLS abundance of BPH from field population was found in 2nd generation successively fed on resistant varieties, and the number of YLS was resumed at 4th generation when the BPH has adapted the resistant varieties. The markedly lower nymphal survival rate, adult fecundity and activities of alanine and aspartic transminase, and significantly longer nymph duration in the three aposymbiotic biotypes than in the symbiotic ones were recorded on both susceptible and resistant rice varieties. However, the much greater differences between aposymbiotic and symbiotic BPH were found on the inadaptable resistant rice varieties than that on the fitness resistant rice varieties. Those results implied that YLS in BPH should playa crucial role in the virulent shift of BPH populations to resistant rice varieties.

Dynamics of Yeast-like Symbiote and its Relationship with the Virulence of Brown Planthopper, Nilaparvata lugens Stal, to Resistant Rice Varieties

Zhong-Xian Lu,Xiao-Ping Yu,Jian-Ming Chen,Xu-Song Zheng,Hong-Xing Xu,Jue-Feng Zhang Zhang,Lie-Zhong Chen 한국응용곤충학회 2004 Journal of Asia-Pacific Entomology Vol.7 No.3

Abundance of the yeast-like symbiote (YLS) in brown planthopper (BPH), Nilaparvata lugens Stl, collected from rice fields in China and obtained from International Rice Research Institute (IRRI), was monitored. The role of YLS in nymph survival rate, development and adult reproduction, and activities of transaminases in BPH on different resistant rice varieties were examined. Also, the relationship between YLS and virulence shifts of BPH to resistant rice varieties was discussed. The results indicated that the virulence of BPH populations to resistant rice varieties was strongly related to the abundance of YLS in 5th instar nymphs and brachypterous females of BPH field populations at Nanning in South China and Hangzhou in East China, showing the more abundance of YLS in BPH, the higher virulence of BPH to resistant rice varieties, while no obvious differences in YLS abundance were monitored between three BPH biotypes. Numbers of YLS reduced significantly in female adult of BPH biotype 1 fed on resistant rice varieties IR26, Mudgo and ASD7, compared with that fed on susceptible rice variety TN1. The lowest YLS abundance of BPH from field population was found in 2nd generation successively fed on resistant varieties, and the number of YLS was resumed at 4th generation when the BPH has adapted the resistant varieties. The markedly lower nymphal survival rate, adult fecundity and activities of alanine and aspartic transminase, and significantly longer nymph duration in the three aposymbiotic biotypes than in the symbiotic ones were recorded on both susceptible and resistant rice varieties. However, the much greater differences between aposymbiotic and symbiotic BPH were found on the inadaptable resistant rice varieties than that on the fitness resistant rice varieties. Those results implied that YLS in BPH should play a crucial role in the virulent shift of BPH populations to resistant rice varieties.

Effects of Plant Nitrogen on Ecological Fitness of the Brown Planthopper, Nilaparvata lugens Stal. in Rice

Lu, Zhong-Xian,Heong, Kong-Luen,Yu, Xiao-Ping,Cui Hu Korean Society of Applied Entomology 2004 Journal of Asia-Pacific Entomology Vol.7 No.1

Ecological fitness characters of the brown planthopper increased proportionally with increase in nitrogen content of rice plants they were bred on. The nymphs survived better and had shorter life spans. Females weighed heavier, laid more eggs and lived longer. In addition, egg hatchability was significantly increased. Number of insects and dry mass from one pair of parents were also significantly higher in high nitrogen plants. Relationships between each of these characters with nitrogen content fitted the linear models well. These characters from insects reared on four successive generations in low, medium and high nitrogen regimes were also investigated. There was little between-generation difference in most characters, except for the population and its dry mass produced by one pairs of insects. This implies that in areas where nitrogen-rich crops are abundant over long periods, ecological fitness of the brown planthoppers are potentially higher and if natural biological control is compromised, the risk of extensive outbreaks are higher. Implications to sudden stoppage of insecticide use in these areas are also discussed.

A Novel Acid-Stable Endo-Polygalacturonase from Penicillium oxalicum CZ1028: Purification, Characterization, and Application in the Beverage Industry

( Zhong Cheng ),( Dong Chen ),( Bo Lu ),( Yutuo Wei ),( Liang Xian ),( Yi Li ),( Zhenzhen Luo ),( Ribo Huang ) 한국미생물 · 생명공학회 2016 Journal of microbiology and biotechnology Vol.26 No.6

Acidic endo-polygalacturonases are the major part of pectinase preparations and extensively applied in the clarification of fruits juice, vegetables extracts, and wines. However, most of the reported fungal endo-polygalacturonases are active and stable under narrow pH range and low temperatures. In this study, an acidic endo-polygalacturonase (EPG4) was purified and characterized from a mutant strain of Penicillium oxalicum. The N-terminal amino acid sequence of EPG4 (ATTCTFSGSNGAASASKSQT) was different from those of reported endopolygalacturonases. EPG4 displayed optimal pH and temperature at 5.0 and 60-70°C towards polygalacturonic acid (PGA), respectively, and was notably stable at pH 2.2-7.0. When tested against pectins, EPG4 showed enzyme activity over a broad acidic pH range (>15.0% activity at pH 2.2-6.0 towards citrus pectin; and >26.6% activity at pH 2.2-7.0 towards apple pectin). The Km and Vmax values were determined as 1.27 mg/ml and 5,504.6 U/mg, respectively. The enzyme hydrolyzed PGA in endo-manner, releasing oligo-galacturonates from PGA, as determined by TLC. Addition of EPG4 (3.6 U/ml) significantly reduced the viscosity (by 42.4%) and increased the light transmittance (by 29.5%) of the papaya pulp, and increased the recovery (by 24.4%) of the papaya extraction. All of these properties make the enzyme a potential application in the beverage industry.

Mechanism Study of Tropical Cyclone Impact on East Asian Subtropical Upper-Level Jet: a Numerical Case Investigation

Xian Chen,Zhong Zhong,Wei Lu 한국기상학회 2018 Asia-Pacific Journal of Atmospheric Sciences Vol.54 No.4

In the case study of this paper, sensitivity experiments are carried out using the mesoscale non-hydrostaticWeather Research and Forecasting (WRF) model to investigate the impact of tropical cyclone (TC) Soudelor (2003) on the East Asian subtropical upper-level jet (EASJ) before TC Soudelor transformed into an extratropical cyclone. The physical mechanism for changes in the EASJ intensity and position caused by TC Soudelor is explored. Results indicate that TC Soudelor would warm the air in the middle and upper troposphere over the Japan Sea and the adjacent areas through stimulating northward propagating teleconnection pattern as well as releasing large amounts of latent heat, which led to increase (decrease) the meridional air temperature gradient to the south (north) below the EASJ axis. As a result, the geopotential height abnormally increased in the upper troposphere, resulting in an anomalous anticyclonic circulation belt along the EASJ axis. Correspondingly, the westerly winds to the north (south) of the EASJ axis intensified (weakened) and the EASJ axis shifted northward by one degree. The case study also suggests that before the extratropical cyclone transition of TC Soudelor, the TC activities had exerted significant impacts on the EASJ through thermodynamic processes.

Evaluation and validation of reference genes for SYBR Green qRT-PCR normalization in Sesamia inferens (Lepidoptera: Noctuidae)

Yanhui Lu,Xu-Song Zheng,Qi Liang,Hong-Xing Xu,Yajun Yang,Junce Tian,Xiaochan He,Zhong-Xian Lu 한국응용곤충학회 2015 Journal of Asia-Pacific Entomology Vol.18 No.4

The pink stemborer, Sesamia inferens (Walker) (Lepidoptera: Noctuidae), has gradually become amajor threat to rice production in Asian rice growth area. Using reverse-transcription quantitative real-time PCR (qRT-PCR) to investigate gene expression of S. inferens under different conditions is a popular technique. However, numerous studies demonstrate that the experimental conditions affect the stability of reference genes. Thus, it is necessary to normalize qRT-PCR data under a specific condition using a stable reference gene as an internal control. In the present study, five algorithms (Delta Ctmethod, Bestkeeper, geNorm,Normfinder, and RefFinder) and seven candidate reference genes were evaluated to find out the most suitable reference genes under different biotic and abiotic conditions including different tissues and developmental stages, exposure to insecticides, different rice varieties, and different diets. Our results showed that the more stable series of reference genes were as follows: GAPDH, RPL10, and RPS3 for different tissues;GAPDH and RPS3 for developmental stages; RPS3 and EF1 for larval insecticide exposure; RPS3 and RPL10 for larvae reared on different rice varieties; RPS3 and ACTB for larvae fed on different diets. Hence, a combination of the best sets of reference genes for normalization of expression analysis will increase the accuracy and reliability of qRT-PCR data in S. inferens. In addition, these results establish the basis for selection of reference genes in other lepidopterous insect species.

A Novel Endo-Polygalacturonase from Penicillium oxalicum: Gene Cloning, Heterologous Expression and Its Use in Acidic Fruit Juice Extraction

( Bo Lu ),( Liang Xian ),( Jing Zhu ),( Yunyi Wei ),( Chengwei Yang ),( Zhong Cheng ) 한국미생물생명공학회 2022 Journal of microbiology and biotechnology Vol.32 No.4

An endo-polygalacturonase (endo-PGase) exhibiting excellent performance during acidic fruit juice production would be highly attractive to the fruit juice industry. However, candidate endo-PGases for this purpose have rarely been reported. In this study, we expressed a gene from Penicillium oxalicum in Pichia pastoris. The recombinant enzyme PoxaEnPG28C had an optimal enzyme activity at pH 4.5 and 45℃ and was stable at pH 3.0-6.5 and < 45℃. The enzyme had a specific activity of 4,377.65 ± 55.37 U/mg towards polygalacturonic acid, and the K_m and V_max values of PoxaEnPG28C were calculated as 1.64 g/l and 6127.45 U/mg, respectively. PoxaEnPG28C increased the light transmittance of orange, lemon, strawberry and hawthorn juice by 13.9 ± 0.3%, 29.4 ± 3.8%, 95.7 ± 10.2% and 79.8 ± 1.7%, respectively; it reduced the viscosity of the same juices by 25.7 ± 1.6%, 52.0 ± 4.5%, 48.2 ± 0.7% and 80.5 ± 2.3%, respectively, and it increased the yield of the juices by 24.5 ± 0.7%, 12.7 ± 2.2%, 48.5 ± 4.2% and 104.5 ± 6.4%, respectively. Thus, PoxaEnPG28C could be considered an excellent candidate enzyme for acidic fruit juice production. Remarkably, fruit juice production using hawthorn as an material was reported for the first time.

Expression and Functional Role of ALDH1 in Cervical Carcinoma Cells

Rao, Qun-Xian,Yao, Ting-Ting,Zhang, Bing-Zhong,Lin, Rong-Chun,Chen, Zhi-Liao,Zhou, Hui,Wang, Li-Juan,Lu, Huai-Wu,Chen, Qin,Di, Na,Lin, Zhong-Qiu Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.4

Tumor formation and growth is dictated by a very small number of tumor cells, called cancer stem cells, which are capable of self-renewal. The genesis of cancer stem cells and their resistance to conventional chemotherapy and radiotherapy via mechanisms such as multidrug resistance, quiescence, enhanced DNA repair abilities and anti-apoptotic mechanisms, make it imperative to develop methods to identify and use these cells as diagnostic or therapeutic targets. Aldehyde dehydrogenase 1 (ALDH1) is used as a cancer stem cell marker. In this study, we evaluated ALDH1 expression in CaSki, HeLa and SiHa cervical cancer cells using the Aldefluor method to isolate ALDH1-positive cells. We showed that higher ALDH1 expression correlated with significantly higher rates of cell proliferation, microsphere formation and migration. We also could demonstrate that SiHa-ALDH1-positive cells were significantly more tumorigenic compared to SiHa-ALDH1-negative cells. Similarly, SiHa cells overexpressing ALDH1 were significantly more tumorigenic and showed higher rates of cell proliferation and migration compared to SiHa cells where ALDH1 expression was knocked down using a lentivirus vector. Our data suggested that ALDH1 is a marker of cervical cancer stem cells and expand our understanding of its functional role.

Time-dependent Nonlinear Theory and Numerical Simulation of Folded Waveguide Traveling Wave Tubes

Wei Feng Peng,Zhong Hai Yang,Yu Lu Hu,Zan Cao,Yin-Fu Hu,Jin-Jun Feng,Xian-Ping Wu 한국물리학회 2013 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.62 No.6

In this paper, a time-dependent nonlinear theory including the generalized time-dependent radiofrequency (RF) field equations is presented to simulate the beam and wave interaction (BWI) of folded waveguide (FWG) traveling wave tubes (TWTs). The analytical RF fields in FWG TWTs are replaced by digitized RF field profiles obtained from electromagnetic simulations. A W-band FWG TWT is studied by using a self-consistent one-dimensional code based on the theory. The numerical results show good predictions when compared with the experimental tests.

Structural characterization and applications of ITS2 from rice leaffolders Cnaphalocrocis medinalis and Marasmia patnalis (Lepidoptera: Pyralidae)

Yajun Yang,ZhihongWu,Xu-Song Zheng,Zhong-Xian Lu,Hong-Xing Xu 한국응용곤충학회 2017 Journal of Asia-Pacific Entomology Vol.20 No.2

Cnaphalocrocis medinalis and Marasmia patnalis are important rice insect pests in Asia and have similarmorphologic features and same feeding patterns. Understanding the molecular difference of the two leaffolders is helpful to their identification and clarification of their phylogenetic class in the Pyraloidea. In this study, we determined and analyzed the nucleotide sequences of nuclear rDNA internal transcribed spacer 2 (ITS2) in the two rice leaffolders from 9 populations (six C. medinalis populations collected from China, Philippine, Thailand, and Vietnam, and threeM. patnalis populations from Philippine, Thailand, and Vietnam) and compared interspecies variation of IST2 among different geographic populations and intraspecies variation of ITS2 from Pyraloidea. Phylogenetic trees were constructed on the two leaffolders and other Pyraloidea species using Maximum Parsimony method. Results showed that the ITS2 sequences differed in the two leaffolders. Compared to C. medinalis, ITS2 ofM. patnalis had small deletion at the sites of 41, 72, 81, 304 and an insertion at the site of 337. Interspecies variation results showed that three C. medinalis populations fromSoutheast Asia (VN, PH, and TH) arewith small divergence compared to NJ andHZ, and small divergencewas observed among threeM. patnalis populations (VN, PH, and TH). Intraspecies variation results showed that two leaffolderswere with close relationship compared to the other Pyraloidea. Phylogenetic trees showed that two leaffolderswere grouped togetherwithMaruca vitrata. These results indicated that the ITS2 sequences differed in the two leaffolders could potentially be used in the distinguishing of the two rice leaffolders and the determination on the phylogeny of species.