作者机构：
[Li, He; Zhu, Yuanye; Ma, Mengting] College of Forestry, Central South University of Forestry and Technology, Changsha, China;[Li, He; Zhu, Yuanye; Ma, Mengting] Key Laboratory of National Forestry, Grassland Administration on Control of Artificial Forest Diseases and Pests in South China, Changsha, China;[Li, He; Zhu, Yuanye; Ma, Mengting] Hunan Provincial Key Laboratory for Control of Forest Diseases and Pests, Changsha, China;[Li, He; Zhu, Yuanye; Ma, Mengting] Key Laboratory for Non-Wood Forest Cultivation and Conservation of Ministry of Education, Changsha, China
关键词：
Colletotrichum fructicola;carbendazim;mechanism of resistance;β-tubulin isotypes
摘要：
Colletotrichum fructicola is the major pathogen of anthracnose in tea-oil trees in China. Control of anthracnose in tea-oil trees mainly depends on the application of chemical fungicides such as carbendazim. However, the current sensitivity of C. fructicola isolates in tea-oil trees to carbendazim has not been reported. Here, we tested the sensitivity of 121 C. fructicola isolates collected from Guangdong, Guangxi, Guizhou, Hainan, Hunan, Jiangsu, and Jiangxi provinces in China to carbendazim. One hundred and ten isolates were sensitive to carbendazim, and 11 isolates were highly resistant to carbendazim. The growth rates, morphology, and pathogenicity of three resistant isolates were identical to those of three sensitive isolates, which indicates that these resistant isolates could form a resistant population under carbendazim application. These results suggest that carbendazim should not be the sole fungicide in control of anthracnose in tea-oil trees; other fungicides with different mechanisms of action or mixtures of fungicides could be considered. In addition, bioinformatics analysis identified two β-tubulin isotypes in C. fructicola: Cfβ(1)tub and Cfβ(2)tub. E198A mutation was discovered in the Cfβ(2)tub of three carbendazim-resistant isolates. We also investigated the functional roles of two β-tubulin isotypes. CfΔβ(1)tub exhibited slightly increased sensitivity to carbendazim and normal phenotypes. Surprisingly, CfΔβ(2)tub was highly resistant to carbendazim and showed a seriously decreased growth rate, conidial production, pathogenicity, and abnormal hyphae morphology. Promoter replacement mutant CfΔβ(2)-2×β(1) showed partly restored phenotypes, but it was still highly resistant to carbendazim, which suggests that Cfβ(1)tub and Cfβ(2)tub are functionally interchangeable to a certain degree.
摘要：
Anthracnose is a common disease found in Camellia oleifera producing areas across China, whose primary pathogen is Colletotrichum fructicola. We previously revealed that autophagy is essential for the pathogenicity of C. fructicola. However, the function of ubiquitin-proteasome system (UPS), which is a parallel protein degradation pathway to autophagy, remains elusive. Here, we report that CfRad6, an E2 conjugating enzyme in UPS, interacts with three putative E3 ubiquitin ligases, namely CfRad18, CfUbr1, and CfBre1. Importantly, we presented evidence showing that CfRad6 negatively regulates autophagy, revealing the first link between UPS and autophagy in pathogenic fungi. Targeted gene deletion showed that CfRad6 is involved in growth and conidiation. We further found that the Delta Cfrad6 mutant is defective in appressoria formation and responses to environmental stresses. These combined effects, along with the abnormal autophagy level, lead to the pathogenicity defects of the Delta Cfrad6 mutant. Taken together, our study indicates the pleiotropic functions of CfRad6 in the development and pathogenicity of C. fructicola.
摘要：
Wood anatomy and plant hydraulics play a significant role in understanding species-specific responses and their ability to manage rapid environmental changes. This study used the dendro-anatomical approach to assess the anatomical characteristics and their relation to local climate variability in the boreal coniferous tree species Larix gmelinii (Dahurian larch) and Pinus sylvestris var. mongolica (Scots pine) at an altitude range of 660 m to 842 m. We measured the xylem anatomical traits (lumen area (LA), cell wall thickness (CWt), cell counts per ring (CN), ring width (RW), and cell sizes in rings) of both species at four different sites Mangui (MG), Wuerqihan (WEQH), Moredagha (MEDG) and Alihe (ALH) and investigated their relationship with temperature and precipitation of those sites along a latitude gradient. Results showed that all chronologies have strong summer temperature correlations. LA extremes were mostly associated with climatic variation than CWt and RWt. MEDG site species showed an inverse correlation in different growing seasons. The correlation coefficient with temperature indicated significant variations in the May-September months at MG, WEQH, and ALH sites. These results suggest that climatic seasonality changes in the selected sites positively affect hydraulic efficiency (increase in the diameter of the earlywood cells) and the width of the latewood produced in P. sylvestris. In contrast, L. gmelinii showed the opposite response to warm temperatures. It is concluded that xylem anatomical responses of L. gmelinii and P. sylvestris showed varied responses to different climatic factors at different sites. These differences between the two species responses to climate are due to the change of site condition on a large spatial and temporal scale.
作者机构：
[Li, He; Wen, Lixia] Cent South Univ Forestry & Technol, Key Lab Natl Forestry & Grassland Adm Control Dis, Changsha 410004, Peoples R China.;[Li, He; Wen, Lixia] Cent South Univ Forestry & Technol, Hunan Prov Key Lab Control Forest Dis & Pests, Changsha 410004, Peoples R China.
通讯机构：
[He Li] K;Key Laboratory of National Forestry and Grassland Administration for Control of Diseases and Pests of South Plantation, Central South University of Forestry and Technology, Changsha 410004, China<&wdkj&>Hunan Provincial Key Laboratory for Control of Forest Diseases and Pests, Central South University of Forestry and Technology, Changsha 410004, China<&wdkj&>Author to whom correspondence should be addressed.
摘要：
Colletotrichum fungi could cause anthracnose, a destructive disease in tea-oil trees. The sterol demethylation inhibitor (DMI) tebuconazole has been widely used in controlling plant diseases for many years. However, the baseline sensitivity of Colletotrichum isolates on tea-oil trees to tebuconazole has not been determined. In this study, the sensitivity to tebuconazole of 117 Colletotrichum isolates from tea-oil trees of seven provinces in southern China was tested. The mean effective concentration resulted in 50% mycelial growth inhibition (EC50), 0.7625 & mu;g/ml. The EC50 values of 100 isolates (83%) were lower than 1 & mu;g/ml, and those of 20 isolates (17%) were higher than 1 & mu;g/ml, which implied that resistance has already occurred in Colletotrichum isolates on tea-oil trees. The EC50 values of the most resistant and sensitive isolates (named Ca-R and Cc-S1, respectively) were 1.8848 and 0.1561 & mu;g/ml, respectively. The resistance mechanism was also investigated in this study. A gene replacement experiment indicated that the CYP51A/B gene of resistant isolates Ca-R and Cf-R1 cannot confer Cc-S1 full resistance to DMI fungicides, although three single point mutants, Cc-S1CYP51A-T306A and Cc-S1CYP51A-R478K, exhibited decreased sensitivity to DMI fungicides. This result suggested that resistance of Colletotrichum isolates was partly caused by mutations in CYP51A. Moreover, the expression level of CYP51A/B was almost identical among Ca-R, Cf-R1, Cc-S1, and Cc-S1CYP51A point mutants, which indicated that the resistance was irrelevant to the expression level of CYP51A, and other nontarget-based resistance mechanisms may exist. Our results could help to guide the application of DMI fungicides and be useful for investigating the mechanism of resistance.
期刊：
Surfaces and Interfaces,2023年39:102913 ISSN：2468-0230
通讯作者：
Wan, YW;Li, H
作者机构：
[Wan, Yiwen; Li, Xiaoling; Lei, Qin; Hong, Bo] Hunan Fisheries Sci Inst, Changsha 410153, Peoples R China.;[Li, He; Li, H; Li, Jiaxin] South China Normal Univ, Sch Chem, Guangzhou Key Lab Analyt Chem Biomed, Guangzhou 510006, Peoples R China.;[Lei, Junjie] Cent South Univ Forestry & Technol, Coll Forestry, Changsha 410006, Peoples R China.
通讯机构：
[Li, H ] S;[Wan, YW ] H;Hunan Fisheries Sci Inst, Changsha 410153, Peoples R China.;South China Normal Univ, Sch Chem, Guangzhou Key Lab Analyt Chem Biomed, Guangzhou 510006, Peoples R China.
关键词：
Photoelectrochemical sensor;chlorpyrifos
摘要：
In this study, a simple wet chemical method was used to prepare p-n heterojunction photoelectric composites (Bi2S3@g-C3N4). The p-n junctions were formed to facilitate charge transfer as well as strongly suppress electron -hole pair recombination, thus enhancing the photoelectrochemical (PEC) characteristics. Particularly, according to the transient surface photocurrent response, the photocurrent intensity of the prepared composites was 2.98 times higher relative to the pristine g-C3N4 material. The photocurrent signal revealed the prepared novel PEC sensor composed of Bi2S3@g-C3N4 composite material, which can be used for sensitively and selectively detecting chlorpyrifos. This method presented a linear change from 50 ng/mL to 0.1 mg/mL of chlorpyrifos under the optimal conditions. The linear regression equation was I(mu A)=0.8546-0.1558lgC(mg/mL) (R2=0.9758) and the detection limit was 0.03 ng/mL (S/N=3). In addition, the novel sensing platform with high selectivity could assist in rapidly and effectively detecting chlorpyrifos in environmental analysis.
摘要：
Camellia oleifera, a woody plant that produces edible oil, is indigenous to China. The devastating disease of anthracnose inflicts significant financial losses on Ca. oleifera. The primary causative agent of anthracnose on Ca. oleifera is Colletotrichum fructicola. Chitin, a pivotal constituent of fungal cell walls, assumes a critical function in their proliferation and maturation. To study the biological functions of chitin synthase 1(Chs1) in C. fructicola, the CfCHS1 gene knockout mutants, increment Cfchs1-1 and increment Cfchs1-2, and their complementary strain, increment Cfchs1/CfCHS1, of C. fructicola were generated. Our results showed that the colony diameters of wild-type and complement-strain increment Cfchs1/CfCHS1, mutant increment Cfchs1-1 and increment Cfchs1-2 cultured on the CM and MM medium were 5.2, 5.0, 2.2 and 2.4 cm and 4.0, 4.0, 2.1 and 2.6 cm, respectively, which were significantly smaller for the mutant than for the wild type and complement strain; the inhibition rates on the CM medium supplemented with H2O2, DTT, SDS and CR were 87.0% and 88.5%, 29.6% and 27.1%, 88.0% and 89.4%, and 41.7% and 28.7%, respectively, for the mutant strains, increment Cfchs1-1 and increment Cfchs1-2, which were significantly higher than those for the other two strains; the rate of hyphal tips with CFW fluorescence in increment Cfchs1-1 and increment Cfchs1-2 was 13.3% and 15.0%, which was significantly lower than those for the other two strains; the mutant strains, increment Cfchs1-1 and increment Cfchs1-2, lost the ability to produce conidia; the mutant strains showed weaker pathogenicity on wounded and unwounded Ca. oleifera leaves than the wild type and complement strain. The findings of this study suggest that CfChs1 plays a crucial role in the growth and development, stress responses, and pathogenicity of C. fructicola. Thus, this gene could be a potential target for developing novel fungicide.
摘要：
Tea oil is widely used as edible oil in China, which extracted from the seeds of Camellia oleifera. In China, the national oil-tea camellia planting area reached 4.533 million hectares, the output of oil-tea camellia seed oil was 627 000 tons, and the total output value reached 18.3 billion dollars. Anthracnose is the common disease of Ca. oleifera, which affected the production and brought huge economic losses. Colletotrichum fructicola is the dominant pathogen causing anthracnose in Ca. oleifera. The retromer complex participates in the intracellular retrograde transport of cargos from the endosome to the trans-Golgi network in eukaryotes. Vacuolar protein sorting 35 is a core part of the retromer complex. This study aimed to investigate the role of CfVps35 in C. fructicola. The CfVPS35 gene was deleted, resulting in reduced mycelial growth, conidiation, and response to cell wall stresses. Further analysis revealed that CfVps35 was required for C. fructicola virulence on tea oil leaves. In addition, the ΔCfvps35 mutant was defective in glycogen metabolism and turgor during appressorium development. This study illustrated that the crucial functions of CfVps35 in growth, development, and pathogenicity.
期刊：
Journal of Fungi,2022年8(8):835- ISSN：2309-608X
通讯作者：
He Li
作者机构：
[Li, He; Li, Xiya; Li, Sizheng] Cent South Univ Forestry & Technol, Grassland Adm Control Artificial Forest Dis & Pes, Key Lab Natl Forestry, Changsha 410004, Peoples R China.;[Li, He] Cent South Univ Forestry & Technol, Hunan Prov Key Lab Control Forest Dis & Pests, Changsha 410004, Peoples R China.
通讯机构：
[He Li] K;Key Laboratory of National Forestry, Grassland Administration on Control of Artificial Forest Diseases and Pests in South China, Central South University of Forestry and Technology, Changsha 410004, China<&wdkj&>Hunan Provincial Key Laboratory for Control of Forest Diseases and Pests, Central South University of Forestry and Technology, Changsha 410004, China<&wdkj&>Author to whom correspondence should be addressed.
摘要：
Camellia oleifera is an edible oil tree species native to China. Anthracnose is a common disease of Ca. oleifera, which reduces the production of the trees and brings huge economic losses. We have previously identified the fungus Colletotrichum fructicola as the major pathogen of anthracnose in Ca. oleifera. The retromer complex participates in the intracellular retrograde transport of the cargos from the endosome to the trans-Golgi network in the eukaryotes. Vacuolar protein sorting 29 is a subunit of the retromer complex. Targeted CfVPS29 gene deletion revealed that CfVps29 is involved in growth, conidiation, and the response to cell wall stress. We further found that the Delta Cfvps29 mutant was minimally pathogenic to Ca. oleifera leaves, as a result of its defect in appressorium formation. This study illustrated the crucial functions of CfVps29 in the development, cell wall stress response, and pathogenicity of C. fructicola and, therefore, identified it as a potential fungicide target for the control of anthracnose.
通讯机构：
[Shengpei Zhang] K;Key Laboratory of National Forestry and Grassland Administration on Control of Artificial Forest Diseases and Pests in South China, Central South University of Forestry and Technology, Changsha 410004, China<&wdkj&>Key Laboratory for Non-wood Forest Cultivation and Conservation of Ministry of Education, Central South University of Forestry and Technology, Changsha 410004, China<&wdkj&>Hunan Provincial Key Laboratory for Control of Forest Diseases and Pests, Central South University of Forestry and Technology, Changsha 410004, China<&wdkj&>College of Forestry, Central South University of Forestry and Technology, Changsha 410004, China<&wdkj&>Author to whom correspondence should be addressed.
关键词：
C. fructicola;autophagy;histone deacetylation;pathogenicity
摘要：
Camellia oleifera is one of the most valuable woody edible-oil crops, and anthracnose seriously afflicts its yield and quality. We recently showed that the CfSnt2 regulates the pathogenicity of Colletotrichum fructicola, the dominant causal agent of anthracnose on C. oleifera. However, the molecular mechanisms of CfSnt2-mediated pathogenesis remain largely unknown. Here, we found that CfSnt2 is localized to the nucleus to regulate the deacetylation of histone H3. The further transcriptomic analysis revealed that CfSnt2 mediates the expression of global genes, including most autophagy-related genes. Furthermore, we provided evidence showing that CfSnt2 negatively regulates autophagy and is involved in the responses to host-derived ROS and ER stresses. These combined functions contribute to the pivotal roles of CfSnt2 on pathogenicity. Taken together, our studies not only illustrate how CfSnt2 functions in the nucleus, but also link its roles on the autophagy and responses to host-derived stresses with pathogenicity in C. fructicola.
作者机构：
[姚权; 李河; 李司政] Key Laboratory of National Forestry and Grassland Administration for Control of Diseases and Pests of South Plantation, Hunan Provincial Key Laboratory for Control of Forest Diseases and Pests, Key Laboratory for Non-Wood Forest Cultivation and Conservation of Ministry of Education, Central South University of Forestry and Technology, Changsha, 410004, China
通讯机构：
[Li, H.] K;Key Laboratory of National Forestry and Grassland Administration for Control of Diseases and Pests of South Plantation, China
期刊：
Journal of Fungi,2021年7(12):1080- ISSN：2309-608X
通讯作者：
Qin Yang<&wdkj&>He Li
作者机构：
Key Laboratory for Non-Wood Forest Cultivation and Conservation of the Ministry of Education, Central South University of Forestry and Technology, Changsha 410004, China;Key Laboratory of National Forestry and Grassland Administration for Control of Diseases and Pests of South Plantation, Central South University of Forestry and Technology, Changsha 410004, China;Hunan Provincial Key Laboratory for Control of Forest Diseases and Pests, Central South University of Forestry and Technology, Changsha 410004, China;Authors to whom correspondence should be addressed.;Hunan Provincial Key Laboratory for Forestry Biotechnology, Central South University of Forestry and Technology, Changsha 410004, China
通讯机构：
[Qin Yang; He Li] A;Authors to whom correspondence should be addressed.<&wdkj&>Key Laboratory for Non-Wood Forest Cultivation and Conservation of the Ministry of Education, Central South University of Forestry and Technology, Changsha 410004, China<&wdkj&>Key Laboratory of National Forestry and Grassland Administration for Control of Diseases and Pests of South Plantation, Central South University of Forestry and Technology, Changsha 410004, China<&wdkj&>Hunan Provincial Key Laboratory for Forestry Biotechnology, Central South University of Forestry and Technology, Changsha 410004, China<&wdkj&>Hunan Provincial Key Laboratory for Control of Forest Diseases and Pests, Central South University of Forestry and Technology, Changsha 410004, China
关键词：
five new taxa;Neopestalotiopsis;Pestalotiopsis;phylogeny;taxonomy
摘要：
Tea-oil tree (Camellia oleifera) is an important edible oil woody plant with a planting area of over 3,800,000 hectares in southern China. Pestalotioid fungi are associated with a wide variety of plants worldwide along with endophytes, pathogens, and saprobes. In this study, symptomatic leaves of C. oleifera were collected from Guangdong, Guangxi, Hainan, Hunan, and Jiangsu Provinces and pestalotioid fungi are characterized based on combined sequence data analyses of internal transcribed spacer (ITS), beta tubulin (tub2), and translation elongation factor 1-alpha (tef-1α) coupled with morphological characteristics. As a result, seven species were confirmed, of which five species are described as new viz. N. camelliae-oleiferae, P. camelliae-oleiferae, P. hunanensis, P. nanjingensis, P.nanningensis, while the other two are reported as known species, viz., N. cubana and N. iberica. Pathogenicity assays showed that all species except for P. nanjingensis developed brown lesions on healthy leaves and P. camelliae-oleiferae showed stronger virulence.
摘要：
Colletotrichum fructicola is a fungal pathogen that causes Camellia oleifera anthracnose. Mitogen-activated protein kinase cascade signaling regulates plants defenses and is modulated by Ste50, a scaffold protein that mediates the interaction of Ste11 and Ste7. In this study, the Saccharomyces cerevisiae STE50 homolog CfSTE50 in C. fructicola was identified and disrupted. CfSTE50 encodes a 482 amino acid protein. The mutants showed significant differences in conidial yields and appressorium failed to form. Vegetative growth also decreased compared to wild-type strains. Inoculation with conidial suspensions showed that the virulence of the mutant on wounded leaves was significantly impaired. Further analysis showed that the targeted deletion of CfSTE50 resulted in enhanced sensitivity to external peroxide stress, but reduced sensitivity to cell wall stress. These results provide evidence that CfSte50 regulates the growth and development of C. fructicola and regulates asexual reproduction, appressorium formation, pathogenicity and the response to external stresses.
