Interspecific differences in thermal tolerance landscape explain aphid community abundance under climate change.

A single critical thermal limit is often used to explain and infer the impact of climate change on geographic range and population abundance. However, it has limited application in describing the temporal dynamic and cumulative impacts of extreme temperatures. Here, we used a thermal tolerance landscape approach to address the impacts of extreme thermal events on the survival of co-existing aphid species (Metopolophium dirhodum, Sitobion avenae and Rhopalosiphum padi). Specifically, we built the thermal death time (TDT) models based on detailed survival datasets of three aphid species with three ages across a broad range of stressful high (34-40 °C) and low (-3∼-11 °C) temperatures to compare the interspecific and developmental stage variations in thermal tolerance. Using these TDT parameters, we performed a thermal risk assessment by calculating the potential daily thermal injury accumulation associated with the regional temperature variations in three wheat-growing sites along a latitude gradient. Results showed that M. dirhodum was the most vulnerable to heat but more tolerant to low temperatures than R. padi and S. avenae. R. padi survived better at high temperatures than Sitobion avenae and M. dirhodum but was sensitive to cold. R. padi was estimated to accumulate higher cold injury than the other two species during winter, while M. dirhodum accrued more heat injury during summer. The warmer site had higher risks of heat injury and the cooler site had higher risks of cold injury along a latitude gradient. These results support recent field observations that the proportion of R. padi increases with the increased frequency of heat waves. We also found that young nymphs generally had a lower thermal tolerance than old nymphs or adults. Our results provide a useful dataset and method for modelling and predicting the consequence of climate change on the population dynamics and community structure of small insects.

A novel nomogram for predicting cancer-specific survival in women with uterine sarcoma: a large population-based study.

BACKGROUND: Uterine sarcoma (US) is a rare malignant uterine tumor with aggressive behavior and rapid progression. The purpose of this study was to constructa comprehensive nomogram to predict cancer-specific survival (CSS) of patients with US-based on the Surveillance, Epidemiology, and End Results (SEER) database. METHODS: A retrospective population-based study was conducted using data from patients with US between 2010 and 2015 from the SEER database. They were randomly divided into a training cohort and a validation cohort ata 7-to-3 ratio. Multivariate Cox analysis was performed to identify independent prognostic factors. Subsequently, a nomogram was established to predict patient CSS. The discrimination and calibration of the nomogram were evaluated by the concordance index (C-index) and the area under the curve (AUC). Finally, net reclassification improvement (NRI), integrated discrimination improvement (IDI), calibration plotting, and decision-curve analysis (DCA) were used to evaluate the benefits of the new prediction model. RESULTS: A total of 3861 patients with US were included in our study. As revealed in multivariate Cox analysis, age at diagnosis, race, marital status, insurance record, tumor size, pathology grade, histological type, SEER stage, AJCC stage, surgery status, radiotherapy status, and chemotherapy status were found to be independent prognostic factors. In our nomogram, pathology grade had strongest correlation with CSS, followed by age at diagnosis and surgery status. Compared to the AJCC staging system, the new nomogram showed better predictive discrimination with a higher C-index in the training and validation cohorts (0.796 and 0.767 vs. 0.706 and 0.713, respectively). Furthermore, the AUC value, calibration plotting, NRI, IDI, and DCA also demonstrated better performance than the traditional system. CONCLUSION: Our study validated the first comprehensive nomogram for US, which could provide more accurate and individualized survival predictions for US patients in clinical practice.

High-Preservation Single-Cell Operation through a Photo-responsive Hydrogel-Nanopipette System.

Single-cell and in situ cell-based operation with nanopipette approach offers a possibility to elucidate the intracellular processes and may aid the improvement of therapy efficiency and precision. We present here a photo-responsive hydrogel-nanopipette hybrid system that can achieve single-cell operation with high spatial/temporal resolution and negligible cell damage. This strategy overcomes long-time obstacles in nanopipette single-cell studies as high electric potential (ca. 1000 mV) or organic solvent is always used during operations, which would inevitably impose disturbance and damage to targeted cells. The light-triggered system promotes a potential-free, non-invasive single-cell injection, resulting in a well-retained cell viability (90 % survival rate). Moreover, the photo-driven injection enables a precisely dose-controllable single-cell drug delivery. Significantly reduced lethal doses of doxorubicin (163-217 fg cell-1 ) are demonstrated in corresponding cell lines.

Monitoring Hydrogen Evolution Reaction Catalyzed by MoS2 Quantum Dots on a Single Nanoparticle Electrode.

Hydrogen evolution reaction (HER) catalyzed by molybdenum sulfide quantum dots (MoS2 QDs) has attracted extensive attention in the energy field. Monitoring HER catalyzed by MoS2 QDs based on a glass nanopore with an electrochemically confined effect was proposed for the first time. MoS2 QDs inside the glass nanopore is driven toward the orifice of the nanopore and bonded with the Ag nanoparticles (Ag NPs) to form a single nanocomposite. When enough voltage is applied across the orifice, the single Ag NP acts as a single nanoparticle electrode to conduct the electrochemically bipolar reaction on its two extremities. In the process, HER is catalyzed by MoS2 QDs, and Ag NPs are oxidized at the same time. The appearance of blockages on the elevated ionic current is attributed to the generation of a H2 bubble. Furthermore, by analyzing the modulations in the ionic current oscillation, the frequency of hydrogen bubble generation that is related to the catalytic efficiency of MoS2 QDs could be estimated. The results reveal the capability of the glass nanopore for the real-time monitoring electrocatalytic behavior, which makes the glass nanopore an ideal candidate to further reveal the heterogeneity of catalytic capability at the single particle level.

[Network pharmacology of flavonoids in Sophora alopecuroides].

The aim of this paper was to investigate the potential pharmacological effect of flavonoids in Sophora alopecuroides by network pharmacology. This study predicted the potential targets of 11 flavonoids of S. alopecuroides with help of reversed pharmacophore matching target recognition service platform (PharmMapper). The pathway information was acquired from DAVID and KEGG databases. Cytoscape software was used to construct the "ingredient-target-pathway" network of flavonoids active components of S. alopecuroides. The flavonoids active components of S. alopecuroides play anti-inflammatory, blood sugar regulating and other pharmacological effects by regulating 62 targets (such as INSR，KDR，MET) and intervening 44 pathways, such as B cell receptor signaling pathway, insulin signaling pathway, neurotrophin signaling pathway, and T cell receptor signaling pathway. In this study, the mechanism of "muti components-multitargets-multiple pathway" of flavonoids was studied. It reflects the multi-components, multi-targets and multiple pathway features of traditional Chinese medicine. Meanwhile, it provides a scientific basis for the elucidation the mechanism of S. alopecuroides as a medicine, and the development and utilization resources of S. alopecuroides.

A 30 nm Nanopore Electrode: Facile Fabrication and Direct Insights into the Intrinsic Feature of Single Nanoparticle Collisions.

Clarifying the hidden but intrinsic feature of single nanoparticles by nanoelectrochemistry could help understand its potential for diverse applications. The uncontrolled interface and bandwidth limitation in the electrochemical measurement put the obstacle in single particle collision. Here, we demonstrate a well-defined 30 nm nanopore electrode with a rapid chemical-electrochemical fabrication method which provides a high reproducibility in both size and performance. A capacitance-based detection mechanism is demonstrated to achieve a high current resolution of 0.6 pA ±0.1 pA (RMS) and a high the temporal resolution of 0.01 ms. By utilizing this electrode, the dynamic interactions of every single particle in the mixture could be directly read during the collision process. The collision frequency is two orders of magnitude higher than previous reports, which helps reveal the hidden features of nanoparticles during the complex and multidimensional interaction processes.

Wireless Bipolar Nanopore Electrode for Single Small Molecule Detection.

Solid-state nanopore-based techniques have become a promising strategy for diverse single molecule detections. Owing to the challenge in well and rapid fabrication of solid-state nanopores with the diameter less than 2 nm, small molecule detection is hard to be addressed by existing label-free nanopore methods. In this work, we for the first time propose a metal-coated wireless nanopore electrode (WNE) which offers a novel and generally accessible detection method for analyzing small molecules and ions at the single molecule/ion level. Here, a silver-coated WNE is developed as a proof-of-principle model which achieves the detection the self-generated H2, the smallest known molecule, and Ag+ at single molecule/ion level by monitoring the enhanced ionic signatures. Under a bias potential of -800 mV, the WNE could accomplish the distinction of as low as 14 H2 molecules and 28 Ag+ from one spike signal. The finite element simulation is introduced to suggest that the generation of H2 at the orifice of the WNE results in the enhanced spike of ionic current. As a proof-of-concept experiment, the WNE is further utilized to directly detect Hg2+ from 100 pM to 100 nM by monitoring the frequency of the spike signals. This novel nanoelectrode provides a brand new label-free, ultrasensitive, and simple detection mechanism for various small molecules/ions detection, especially for redox analytes.

The adenosine deaminase gene polymorphism is associated with chronic heart failure risk in Chinese.

Adenosine (Ado) is an important cardioprotective agent. Since endogenous Ado levels are affected by the enzyme Ado deaminase (ADA), polymorphisms within the ADA gene may exert some effect on chronic heart failure (CHF). This study applied a case-control investigation to 300 northern Chinese Han CHF patients and 400 ethnicity-matched healthy controls in which nine single-nucleotide polymorphisms (SNPs) of ADA were genotyped and association analyses were performed. Odds ratios (ORs) with 95% confidence intervals (CI) were used to assess the association. Overall, rs452159 polymorphism in ADA gene was significantly associated with susceptibility to CHF under the dominant model (p = 0.013, OR = 1.537, 95% CI = 1.10-2.16), after adjustment for age, sex, and traditional cardiovascular risk factors. No difference in genotype distribution and allele frequency for the rs452159 according to the functional New York Heart Association class was found. Furthermore, the values of left ventricular ejection fraction, left-ventricle end-diastolic diameter or left-ventricle end-systolic diameter did not differ significantly among the different rs452159 genotype CHF patients. Although further studies with larger cohorts and other ethnicities are required to validate the conclusions, the findings of this study potentially provide novel insight into the pathogenesis of CHF.

The interspecific variations in molecular responses to various doses of heat and cold stress: The case of cereal aphids.

Insects are currently subjected to unprecedented thermal stress due to recent increases in the frequency and amplitude of temperature extremes. Understanding molecular responses to thermal stress is critically important to appreciate how species react to thermal stress. Three co-occurring cosmopolitan species are found within the guild of cereal aphids: Sitobion avenae, Ropalosiphum padi and Metopolophium dirhodum. Earlier reports have shown that increasing frequency of temperature extremes causes a shift in dominant species within guilds of cereal aphids by differently altering the population's growth. We hypothesize that a differential molecular response to stress among species may partially explain these changes. Heat shock proteins (HSPs) are molecular chaperones well known to play an important role in protecting against the adverse effects of thermal stress. However, few studies on molecular chaperones have been conducted in cereal aphids. In this study, we compared the heat and cold tolerance between three aphid species by measuring the median lethal time (Lt50) and examined the expression profiles of seven hsp genes after exposures to comparable thermal injury levels and also after same exposure durations. Results showed that R. padi survived comparatively better at high temperatures than the two other species but was more cold-sensitive. Hsp genes were induced more strongly by heat than cold stress. Hsp70A was the most strongly up-regulated gene in response to both heat and cold stress. R. padi had more heat inducible genes and significantly higher mRNA levels of hsp70A, hsp10, hsp60 and hsp90 than the other two species. Hsps ceased to be expressed at 37 °C in M. dirhodum and S. avenae while expression was maintained in R. padi. In contrast, M. dirhodum was more cold tolerant and had more cold inducible genes than the others. These results confirm species-specific differences in molecular stress responses and suggest that differences in induced expression of hsps may be related to species' thermal tolerance, thus causing the changes in the relative abundance.

How to use the Surveillance, Epidemiology, and End Results (SEER) data: research design and methodology.

In the United States (US), the Surveillance, Epidemiology, and End Results (SEER) program is the only comprehensive source of population-based information that includes stage of cancer at the time of diagnosis and patient survival data. This program aims to provide a database about cancer incidence and survival for studies of surveillance and the development of analytical and methodological tools in the cancer field. Currently, the SEER program covers approximately half of the total cancer patients in the US. A growing number of clinical studies have applied the SEER database in various aspects. However, the intrinsic features of the SEER database, such as the huge data volume and complexity of data types, have hindered its application. In this review, we provided a systematic overview of the commonly used methodologies and study designs for retrospective epidemiological research in order to illustrate the application of the SEER database. Therefore, the goal of this review is to assist researchers in the selection of appropriate methods and study designs for enhancing the robustness and reliability of clinical studies by mining the SEER database.

Data mining in clinical big data: the frequently used databases, steps, and methodological models.

Many high quality studies have emerged from public databases, such as Surveillance, Epidemiology, and End Results (SEER), National Health and Nutrition Examination Survey (NHANES), The Cancer Genome Atlas (TCGA), and Medical Information Mart for Intensive Care (MIMIC); however, these data are often characterized by a high degree of dimensional heterogeneity, timeliness, scarcity, irregularity, and other characteristics, resulting in the value of these data not being fully utilized. Data-mining technology has been a frontier field in medical research, as it demonstrates excellent performance in evaluating patient risks and assisting clinical decision-making in building disease-prediction models. Therefore, data mining has unique advantages in clinical big-data research, especially in large-scale medical public databases. This article introduced the main medical public database and described the steps, tasks, and models of data mining in simple language. Additionally, we described data-mining methods along with their practical applications. The goal of this work was to aid clinical researchers in gaining a clear and intuitive understanding of the application of data-mining technology on clinical big-data in order to promote the production of research results that are beneficial to doctors and patients.

[Roles of REV3 in proliferation and genomic stability of colon carcinoma cells].

To investigate the roles of human REV3 gene in proliferation and genomic stability, we experimentally suppressed the REV3 expression in human colon cancer cells (SW480) by the interference RNA technology (RNAi) as monitored by real-time RT-PCR. Compared to untreated or mock-treated cells, ablation of REV3 significantly reduced cell growth rate, micronucleus formation and the frequency of sister chromatid exchange. Whereas the differences between untreated and mock-treated controls were insignificant. Indicators of cell cycle, proliferation and the expression of genetic information in cells of case group, which displayed lower-level expression of REV3, were extremely lower than the control group, and the difference was significant (P<0.05). Differences in the two control groups were not significant. This suggested that the reduced expression of REV3 may affect the growth and proliferation of colon cancer cells (SW480), and, to some extent, contribute to suppression of the genetic instability occurred in micronuclei and sister chromatids. Based on the results from this study, REV3 plays an important role in different cellular growth periods and physiological conditions, and its differential expression directly affects the development of human colon cancer cells.

Global and regional burdens of oral cancer from 1990 to 2017: Results from the global burden of disease study.

BACKGROUND: Data on the incidence, mortality, and other burden of oral cancer as well as their secular trends are necessary to provide policy-makers with the information needed to allocate resources appropriately. The purpose of this study was to use the Global Burden of Disease (GBD) 2017 results to estimate the incidence, mortality, and disability-adjusted life years (DALYs) for oral cancer from 1990 to 2017. METHODS: We collected detailed data on oral cancer from 1990 to 2017 from the GBD 2017. The global incidence, mortality, and DALYs attributable to oral cancer as well as the corresponding age-standardized rates (ASRs) were calculated. The estimated annual percentage changes in the ASRs of incidence (ASRI) and mortality (ASRM) and age-standardized DALYs of oral cancer were also calculated according to regions and countries to quantify the secular trends in these rates. RESULTS: We tracked the incidence, mortality, and DALYs of oral cancer in 195 countries/territories over 28 years. Globally, the incidence, mortality, and DALYs of oral cancer increased by about 1.0-fold from 1990 to 2017. The ASRI of oral cancer showed a similar trend, increasing from 4.41 to 4.84 per 100,000 person-years during the study period. The ASRM remained approximately stable at about 2.4 per 100,000 from 1990 to 2017, as did the age-standardized DALYs, at about 64.0 per 100,000 person-years. ASRI was highest in Pakistan (27.03/100,000, 95% CI = 22.13-32.75/100,000), followed by Taiwan China, and lowest in Iraq (0.96/100,000, 95% CI = 0.86-1.06/100,000). ASRM was highest in Pakistan (16.85/100,000, 95% CI = 13.92-20.17/100,000) and lowest in Kuwait (0.51/100,000, 95% CI = 0.45-0.58/100,000). CONCLUSIONS: The ASRI of oral cancer has increased slightly worldwide, while the ASRM and age-standardized DALY have remained stable. However, these characteristics vary between countries, suggesting that current prevention strategies should be reoriented, and much more targeted and specific strategies should be established in some countries to forestall the increase in oral cancer.

Effect of actuation sequence on flow rates of peristaltic micropumps with PZT actuators.

Many biomedical applications require the administration of drugs at a precise and preferably programmable rate. The flow rate generated by the peristaltic micropumps used in such applications depends on the actuation sequence. Accordingly, the current study performs an analytical and experimental investigation to determine the correlation between the dynamic response of the diaphragms in the micropump and the actuation sequence. A simple analytical model of a peristaltic micropump is established to analyze the shift in the resonant frequency of the diaphragms caused by the viscous damping effect. The analytical results show that this damping effect increases as the oscillation frequency of the diaphragm increases. A peristaltic micropump with three piezoelectric actuators is fabricated on a silicon substrate and is actuated using 2-, 3-, 4- and 6-phase actuation sequences via a driving system comprising a microprocessor and a phase controller. A series of experiments is conducted using de-ionized water as the working fluid to determine the diaphragm displacement and the flow rates induced by each of the different actuation sequences under phase frequencies ranging from 50 Hz to 1 MHz. The results show that the damping effect of actuation sequences influences diaphragm resonant frequency, which in turn affects the profiles of flow rates.

[The protective roles of tiangui gengnian soft capsule on brain in aged female rats and its mechanism].

OBJECTIVE: To investigate the brain-protective and anti-aging effects and the mechanism of action of Tiangui Gengnian Soft Capsule (TGSC), a Chinese herbal preparation composed of sea buckthorn fatty acids. METHODS: Sixteen-month-old female rats were administered via gastric perfusion with low, medium and high doses (0.72 g/kg, 1.80 g/kg and 4.5 g/kg) of TGSC for 180 days. The 3-month and 22-month old rats were taken as controls. Expression of estrogen receptor beta(ERbeta), tyrosine hydroxylase (TH), granulocyte colony-stimulating factor (G-CSF) and vascular endothelial growth factor (VEGF) in the brain of rats were observed and analyzed using immunohistochemical technique, and changes in the number of neurons and glial cells were counted with Nissl's staining. RESULTS: Immunohistochemistry showed the number of ERbeta- and TH-positive neurons in the hypothalamus was significantly higher (P < 0.01 and P < 0.05), G-CSF-positive astrocyte stain was much weaker (P < 0.01) and the expression of VEGF-positive cerebral vessel was stronger (P < 0.05) in the TGSC treated groups than those in the control. Nissl's staining showed no significant difference in the number of neurons and glial cells among groups. CONCLUSION: TGSC could up-regulate the expressions of ERbeta, TH and VEGF in the brain of aged female rats, modulate the responsibility of astrocyte and its G-CSF expression, suggesting that TGSC may have certain neuro-protective and anti-aging effects.

Single molecule sensing of amyloid-ß aggregation by confined glass nanopores.

We have developed a glass nanopore based single molecule tool to investigate the dynamic oligomerization and aggregation process of Aß1-42 peptides. The intrinsic differences in the molecular size and surface charge of amyloid aggregated states could be distinguished through single molecule induced characteristic current fluctuation. More importantly, our results reveal that the neurotoxic Aß1-42 oligomer tends to adsorb onto the solid surface of nanopores, which may explain its instability and highly neurotoxic features.

Nomograms for predicting long-term overall survival and cancer-specific survival in lip squamous cell carcinoma: A population-based study.

BACKGROUND: The goal of this study was to establish and validate two nomograms for predicting the long-term overall survival (OS) and cancer-specific survival (CSS) in lip squamous cell carcinoma (LSCC). METHODS: This study selected 4175 patients who were diagnosed with LSCC between 2004 and 2015 in the SEER (Surveillance, Epidemiology, and End Results) database. The patients were allocated randomly to a training cohort and validation cohort. Variables were selected using a backward stepwise method in a Cox regression model. Based on the predictive model with the identified prognostic factors, nomograms were established to predict the 3-, 5-, and 8-year survival OS and CSS rates of LSCC patients. The accuracy of the nomograms was evaluated based on the consistency index (C-index), while their prediction accuracy was evaluated using calibration plots. Decision curve analyses (DCAs) were used to evaluate the performance of our survival model. RESULTS: The multivariate analyses demonstrated that age at diagnosis, marital status, sex, race, American Joint Committee on Cancer stage, surgery status, and radiotherapy status were risk factors for both OS and CSS. The C-index, area under the time-dependent receiver operating characteristic curve, and calibration plots demonstrated the good performance of the nomograms. DCAs of both nomograms further showed that they exhibited good 3-, 5-, and 8-year net benefits. CONCLUSIONS: We have developed and validated LSCC prognosis nomograms for OS and CSS for the first time. These nomograms can be valuable tools for clinical practice when clinicians are helping patients to understand their survival risk for the next 3, 5, and 8 years.

Wireless nanopore electrodes for analysis of single entities.

Measurements of a single entity underpin knowledge of the heterogeneity and stochastics in the behavior of molecules, nanoparticles, and cells. Electrochemistry provides a direct and fast method to analyze single entities as it probes electron/charge-transfer processes. However, a highly reproducible electrochemical-sensing nanointerface is often hard to fabricate because of a lack of control of the fabrication processes at the nanoscale. In comparison with conventional micro/nanoelectrodes with a metal wire inside, we present a general and easily implemented protocol that describes how to fabricate and use a wireless nanopore electrode (WNE). Nanoscale metal deposition occurs at the tip of the nanopipette, providing an electroactive sensing interface. The WNEs utilize a dynamic ionic flow instead of a metal wire to sense the interfacial redox process. WNEs provide a highly controllable interface with a 30- to 200-nm diameter. This protocol presents the construction and characterization of two types of WNEs-the open-type WNE and closed-type WNE-which can be used to achieve reproducible electrochemical measurements of single entities. Combined with the related signal amplification mechanisms, we also describe how WNEs can be used to detect single redox molecules/ions, analyze the metabolism of single cells, and discriminate single nanoparticles in a mixture. This protocol is broadly applicable to studies of living cells, nanomaterials, and sensors at the single-entity level. The total time required to complete the protocol is ~10-18 h. Each WNE costs ~$1-$3.

[Role of hREV3 in cell cycle and proliferation].

Using a stable human kidney embryonic cell line HEK-293-M-REV3- in which the REV3 gene expression is suppressed by antisense RNA, we measured cell cycle progression and proliferation in an attempt to valuate the roles of REV3 in mutagenesis and tumorigenesis. HEK-293-M-REV3- cells were untreated or treated with DNA damaging agent UVB irradiation or methyl methanesulfonate (MMS), followed by flow cytometry and cell counting to determine the cell cycle distribution and proliferation index (PI). This study revealed that suppression of REV3 delayed spontaneous S phase progression. When treated with MMS or UVB, HEK-293-M-REV3- cells were arrested at S or G2-M phase of the cell cycle, resulting in an increased PI. In light of our previous report that suppression of REV3 limits spontaneous and DNA dam-age-induced mutagenesis, we speculate that failure in translesion synthesis due to the abolation of DNA Polymerasex may cause frequent replication fork arrest and account for the prolonged cell cycle, which is further manifested by external sources of DNA damage. Furthermore, persistent replication fork arrest may evoke cell death or apoptosis.

Cell-wall-degrading enzymes produced in vitro and in vivo by Rhizoctonia solani, the causative fungus of peanut sheath blight.

Rhizoctonia solani causes the disease peanut sheath blight, involving symptoms of maceration and necrosis of infected tissue, mainly caused by cell-wall-degrading enzymes (CWDEs). This study investigated the production of CWDEs including polygalacturonase (PG), polymethyl-galacturonase (PMG), cellulase (Cx) and ß-glucosidase by R. solani in vitro (in liquid culture) and in vivo (in peanut plants). Significant PG, PMG, Cx and ß-glucosidase activities were detected in infected tissues including stalk and leaves of Baisha and Silihong peanut cultivars. Extracts of healthy tissue showed little or no such activities. In shaken liquid cultures of R. solani in medium containing pectin or pectin plus carboxymethyl cellulose (CMC) as the carbon source(s), PG and PMG were notably active. Significant Cx activity was detected in cultures with CMC or pectin plus CMC as the carbon source(s). However, only a very low level of ß-glucosidase activity was observed in cultures with any of the tested carbon sources. An increase of pH was recorded in decayed peanut tissues and liquid culture filtrates; the filtrate pH and fungal growth positively correlated. The fungal growth and/or pH were important factors for the production of PG, PMG and Cx in culture with pectin plus CMC as the carbon source. A single active PG isozyme with isoelectric point around 9.2 was detected in culture filtrates and in infected peanut tissues by the method of isoelectric focusing electrophoresis. The crude enzymes extracted from liquid culture of R. solani induced decay of healthy peanut leaves.