The Casparian strip membrane domain proteins (CASPs) are pivotal for the formation of the Casparian strip (CS) in endodermal cells and play a crucial role in a plant’s response to environmental stresses. However, existing research on the CASP gene family in rice and Arabidopsis lacks a comprehensive bioinformatics analysis and necessitates further exploration. In this study, we identified 41 OsCASP and 39 AtCASP genes, which were grouped into six distinct subgroups. Collinearity analysis underscored the pivotal roles of WGD and TD events in driving the evolution of CASPs, with WGDs being the dominant force. On the one hand, the analysis of cis-elements indicated that most OsCASP and AtCASP genes contain MYB binding motifs. On the other hand, RNA-seq revealed that the majority of OsCASP and AtCASP genes are highly expressed in roots, particularly in endodermal cells, where OsCASP_like11/9 and AtCASP_like1/31 demonstrated the most pronounced expression. These results suggest that OsCASP_like11/9 and AtCASP_like1/31 might be candidate genes involved in the formation of the endodermis CS. RT-qPCR results demonstrated that OsCASP_like2/3/13/17/21/30 may be candidate genes for the ion defect process. Collectively, this study offers a theoretical foundation for unraveling the biological functions of CASP genes in rice and Arabidopsis.

Sorghum northern anthracnose is a leaf disease affecting sorghum, which results in plant death and substantial yield loss. This study aimed to effectively understand the disease, clarify its biological characteristics, and evaluate the resistance of germplasm resources. A field sample was collected to isolate and purify the pathogen. The pathogen, identified as Kabatiella zeae Narita et Hiratsuka using both morphological and molecular techniques, was further confirmed as the causative agent of northern anthracnose of sorghum following Robert Koch’s principles. The results revealed the optimal culture temperature to be 25 °C, preferred dark culture conditions, and the best growth on potato glucose agar medium with sucrose and L-leucine as the optimal carbon and nitrogen sources, respectively. A total of 138 sorghum germplasm resources were inoculated and evaluated using the isolated pathogen, with 20 lines (14.49%) exhibiting high resistance, 18 lines (13.04%) showing disease resistance, 27 lines (19.57%) demonstrating medium resistance, 37 lines (26.81%) being susceptible, and 36 lines (26.09%) classified as highly susceptible. The indoor fungicide screening was conducted through pathogen medium application, and enilconazole, pyraclostrobin, methylthiophanate, and flusilazole were screened for the best fungicide inhibition with a 100% inhibition rate compared with the control. This study provides reference for field pharmaceutical control in sorghum production.

Broccoli (Brassica oleracea var. italica) is not only an important crop worldwide with a large amount of production and consumption annually, but also rich in biologically active compounds (Surh et al., 2021). In November 2022, an unknown leaf blight was observed in the Broccoli planting area, Wenzhou City of Zhejiang Province (28.05 °N, 120.31 °E). Symptoms initially occurred at the leaf margin with yellow to gray lesions that were irregular and wilting. Approximately 10% of the surveyed plants were affected. To determine the pathogen, leaves with blight were collected randomly from five B. oleracea plants. Tissue blocks (3×3 mm) from diseased leaf portions were disinfected with 75% ethanol, rinsed three times with sterilized water, placed aseptically onto potato dextrose agar (PDA) medium, and incubated for 5 days at 28℃ in darkness. Seven fungal isolates with the same morphology were obtained using the spore method. The observed colonies were circular, taupe, pewter in color with light gray edging and many cottony aerial mycelia. Conidia were straight, curved or slightly bent, ellipsoidal to fusiform, and septate (typically 4-8 septa per conidium), with the size of 50.0-90.0 μm × 10.0-20.0 μm (n=30). The conidia had a slightly protruding and truncate hilum. These morphological characteristics were consistent with Exserohilum rostratum (Sharma et al., 2014). To further identify the pathogen, isolate WZU-XLH1 was chosen as a representative and the internal transcribed spacer (ITS) and glyceraldehyde-3-phosphate dehydrogenase-like (GAPDH) gene were amplified and sequenced using primer pairs ITS1/ITS4 (White et al., 1990) and Gpd1/Gpd2 (Berbee et al., 1999), respectively. The ITS and gpd gene sequences of isolate WZU-XLH1 were deposited in the GenBank database with accession numbers OQ750113 and OQ714500, respectively. BLASTn analysis showed matches of 568/571 (MH859108) and 547/547 (LT882549) with Exserohilum rostratum CBS 188.68. A neighbor-joining phylogenetic tree was constructed by combining the two sequenced loci, this isolate in the E. rostratum species complex clade at 71% bootstrap support.To verify the pathogenicity of the isolate, ten healthy Broccoli (cultivar 'You Xiu') seedlings with at least five leaves were divided into two groups: one group was inoculated with the isolate, while the other group served as a control. After surface disinfection with 75% ethanol and wiping with sterile water, tiny wounds were made on two leaves (two wounds in one leaf) using an inoculation needle. Fungal culture plugs cut from the isolate were placed on the wounds, while sterile PDA plugs served as the control. The leaves were sealed in wet airtight bags to retain moisture at room temperature with natural light (Cao et al., 2022). After five days, all leaves inoculated with isolate WZU-XLH1 showed symptoms identical to those observed in the field, with no symptoms present in the control group. The pathogenicity was confirmed by repeating the test in triplicate, and fungi re-isolated from symptomatic leaves were identified as E. rostratum by the morphological and molecular methods described above. To the best of our knowledge, this is the first report of E. rostratum causing leaf blight on broccoli in China. This study contributes to our understanding of B. oleracea leaf blight and establishes a basis for future studies on E. rostratum to develop management strategies.

HomePlant DiseaseVol. 106, No. 6Occurrence of Neopestalotiopsis clavispora Causing Leaf Spot on Dendrobium officinale in China PreviousNext DISEASE NOTE OPENOpen Access licenseOccurrence of Neopestalotiopsis clavispora Causing Leaf Spot on Dendrobium officinale in ChinaPeng Cao, Yuhui Fang, Zikui Zheng, Xia Han, Huixi Zou, and Xiufeng YanPeng Caohttps://orcid.org/0000-0002-7531-5096National and Local Joint Engineering Research Center of Ecological Treatment Technology for Urban Water Pollution, Zhejiang Provincial Key Laboratory for Water Environment and Marine Biological Resources Protection, College of Life and Environmental Science, Wenzhou University, Zhong-Xin Street, Wenzhou 325035, China, Yuhui FangNational and Local Joint Engineering Research Center of Ecological Treatment Technology for Urban Water Pollution, Zhejiang Provincial Key Laboratory for Water Environment and Marine Biological Resources Protection, College of Life and Environmental Science, Wenzhou University, Zhong-Xin Street, Wenzhou 325035, China, Zikui ZhengNational and Local Joint Engineering Research Center of Ecological Treatment Technology for Urban Water Pollution, Zhejiang Provincial Key Laboratory for Water Environment and Marine Biological Resources Protection, College of Life and Environmental Science, Wenzhou University, Zhong-Xin Street, Wenzhou 325035, China, Xia HanNational and Local Joint Engineering Research Center of Ecological Treatment Technology for Urban Water Pollution, Zhejiang Provincial Key Laboratory for Water Environment and Marine Biological Resources Protection, College of Life and Environmental Science, Wenzhou University, Zhong-Xin Street, Wenzhou 325035, China, Huixi ZouNational and Local Joint Engineering Research Center of Ecological Treatment Technology for Urban Water Pollution, Zhejiang Provincial Key Laboratory for Water Environment and Marine Biological Resources Protection, College of Life and Environmental Science, Wenzhou University, Zhong-Xin Street, Wenzhou 325035, China, and Xiufeng Yan†Corresponding author: X. Yan; E-mail Address: [email protected]National and Local Joint Engineering Research Center of Ecological Treatment Technology for Urban Water Pollution, Zhejiang Provincial Key Laboratory for Water Environment and Marine Biological Resources Protection, College of Life and Environmental Science, Wenzhou University, Zhong-Xin Street, Wenzhou 325035, ChinaAffiliationsAuthors and Affiliations Peng Cao Yuhui Fang Zikui Zheng Xia Han Huixi Zou Xiufeng Yan † National and Local Joint Engineering Research Center of Ecological Treatment Technology for Urban Water Pollution, Zhejiang Provincial Key Laboratory for Water Environment and Marine Biological Resources Protection, College of Life and Environmental Science, Wenzhou University, Zhong-Xin Street, Wenzhou 325035, China Published Online:11 May 2022https://doi.org/10.1094/PDIS-11-21-2432-PDNAboutSectionsView articlePDFSupplemental ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmailWechat View articleDendrobium officinale Kimura L., an endangered orchid, is a precious herb used in Chinese traditional medicine (Zheng et al. 2005). In August 2021, significant indications of an unknown leaf spot disease were observed on greenhouse-grown D. officinale in Yueqing, Wenzhou (28.39°N, 121.04°E), Zhejiang Province, China, the main production center of this orchid. Approximately 20% of plants surveyed showed typical infection symptoms. Initially, symptoms appeared as small, circular black spots. As the disease developed, the center of the lesions was sunken with a black border. To determine the causal agent, 10 symptomatic samples were collected and all pieces from symptomatic leaves were used for isolating the pathogen. Tissues between healthy and necrotic areas were cut into pieces (5 × 5 mm, n = 10), disinfected with 10% NaOCl for 1 min, rinsed three times with sterile water, and dried on sterile tissue. Single samples were placed on potato dextrose agar medium (PDA) plates and incubated at 25°C in a dark biochemical incubator. After 3 days, hyphal tips growing from the disinfected tissues were individually transferred to new PDA plates and incubated at 25°C in the dark. Twelve identical fungal isolates were obtained from all symptomatic leaf fragments; DDO11 was chosen as a representative for further study. Colonies had white aerial mycelium after 5 days of culture at 25°C on PDA. Black viscous acervuli were scattered on the colony surface after 8 to 12 days of culture. Conidia were spindle shaped, five cells, four septa, average 29.3 × 8.5 μm (n = 30). Apical and basal cells were lighter in color, and most were hyaline. The middle three cells were darker in color, and mostly brown. There were two to four colorless, transparent unbranched accessory filaments at the top, 32.5 µm in average length, and basal cells had a small appendage, 9.2 µm in average length, n = 30. For species identification, the internal transcribed spacer (ITS) region, β-tubulin gene (TUB2), and translation elongation factor-1α (TEF-1α) were amplified (Qiu et al. 2020). The ITS, TUB2, and TEF-1α gene sequences of DDO11 were deposited in NCBI GenBank (OK631881, OK655895, and OK655896, respectively). BLASTn analysis showed, respectively, 100, 100, and 99.6% nucleotide sequence identity with Neopestalotiopsis clavispora strain accessions MG729690, MG740736, and MH423940, indicating that the pathogen belonged to N. clavispora. A maximum-likelihood phylogenetic analysis based on multilocus sequence (ITS, TUB2, and TEF-1α) using MEGA X had a similar result (Kumar et al. 2018). Pathogenicity was tested on healthy, 1-year-old D. officinale 'Yandang1'. Spores of DDO11 were produced on PDA for 7 days at 28°C and washed with sterile distilled water, and concentrations were adjusted to 106 spores/ml using a hemocytometer. Fifteen surface-disinfected healthy plants were inoculated by spraying the suspension (2 ml, 106 spores/ml) and covered with plastic bags for 24 h; 15 control plants were treated with sterile distilled water. The plants were placed in a chamber at >95% relative humidity and 25°C for 48 h and kept in a growth chamber (Kiangnan, China) at 25°C with 12-h day/night cycle for 8 days (Cao et al. 2019). All inoculated leaves showed symptoms identical to those observed in the field. No disease occurred on the controls. The Neopestalotiopsis isolate was reisolated from the symptomatic leaves, and the species was confirmed by the morphological and molecular methods described above. N. clavispora has been reported to cause diseases on various plants worldwide, such as strawberry (Gilardi et al. 2019), blueberry (Shi et al. 2022), Syzygium cumini (Banerjee and Rana 2020), and Macadamia (Qiu et al. 2020). To the best of our knowledge, this is the first report of N. clavispora causing leaf spot on D. officinale in China. This report will help to recognize the leaf spot disease of D. officinale and establish a basis for future studies on N. clavispora to develop management strategies.The author(s) declare no conflict of interest.References:Banerjee A., and Rana, D. 2020. Plant Dis. 104:1255. https://doi.org/10.1094/PDIS-09-19-2018-PDN Link, ISI, Google ScholarCao, P., et al. 2019. Plant Dis. 103:1768. https://doi.org/10.1094/PDIS-09-18-1603-PDN Link, Google ScholarGilardi G., et al. 2019. Plant Dis. 103:2959. https://doi.org/10.1094/PDIS-03-19-0673-PDN Link, ISI, Google ScholarKumar S., et al. 2018. Mol Biol Evol. 35:1547. Crossref, ISI, Google ScholarQiu F., et al. 2020. Plant Dis. 104:288. https://doi.org/10.1094/PDIS-07-19-1367-PDN Link, ISI, Google ScholarShi, J., et al. 2022. Plant Dis. 106:1307. https://doi.org/10.1094/PDIS-07-21-1376-PDN Link, Google ScholarZheng, X., et al. 2005. Chin. N. Drugs J. 14:826. Google ScholarP. Cao and Y. Fang contributed equally to this work.Funding: This work was supported by Zhejiang Basic Public Welfare Research Plan (LGN19C020004).The author(s) declare no conflict of interest.DetailsFiguresLiterature CitedRelated Vol. 106, No. 6 June 2022SubscribeISSN:0191-2917e-ISSN:1943-7692 Download Metrics Article History Issue Date: 2 Jun 2022Published: 11 May 2022First Look: 12 Jan 2022Accepted: 4 Jan 2022 Page: 1761 Information© 2022 The American Phytopathological SocietyFundingZhejiang Basic Public Welfare Research PlanGrant/Award Number: LGN19C020004KeywordsDendrobium officinale Kimura L.leaf spotNeopestalotiopsis clavisporaThe author(s) declare no conflict of interest.PDF downloadCited byPestalotioid Species Associated with Medicinal Plants in Southwest China and ThailandMicrobiology Spectrum, Vol. 11, No. 1First report of Neopestalotiopsis clavispora causing leaf spot on Liquidambar formosana in ChinaRou Ye, Yanqiu Wang, Shengxiang Lu, Baishuan Lv, Yong-Chun Zeng, and Yang Zhang1 February 2023 | Plant Disease, Vol. 0, No. jaFusarium spp. Associated with Dendrobium officinale Dieback Disease in China29 August 2022 | Journal of Fungi, Vol. 8, No. 9

Ougan (Citrus reticulata cv. Suavissima) is a distinct citrus cultivar local to Zhejiang province, China. (Guo et al. 2021). In November 2021, an unknown postharvest fruit rot was observed in the Sanyang wetland Ougan planting area, Wenzhou City of Zhejiang Province (27.96 °N, 120.69 °E). About 3% of diseased fruits with similar fruit rot symptoms were observed in 900 mandarin fruits from four commercial storages. Initially, the symptoms appeared as light brown lesions that turned deep brown as the lesions expanded. To identify the pathogen, segments (5 mm2) from margins of rotted tissue were excised from 5 symptomatic fruits, surface disinfested twice with 75% ethanol, rinsed three times with sterilized water, placed aseptically onto potato dextrose agar (PDA) medium and incubated for 7 days at 25℃ in darkness for identification. Five fungal isolates with the same morphology were obtained using the single spore method (Leslie and Summerell 2006). Initially, the fungus produced fluffy and white aerial mycelium that eventually turned green on PDA medium after 3 days. Conidiophores were broom-shaped (17.5 ± 2.5 μm) (n=50). Conidia were unicellular and ellipsoid (3.5 to 5.0 ×2.5 to 4.0 μm) (n=50). These morphological characteristics were consistent with Penicillium species (Wu et al. 2022). WZU-OG1 was chosen as a representative isolate for further study. For molecular identification, PCR amplification and DNA sequencing were performed using primers ITS1/ITS4 (White et al. 1990), bt2a/bt2b (Glass and Donaldson 1995), and RPB2-5F/RPB2-7R (Liu et al. 1999) to amplify the complete internal transcribed spacer (ITS) region, β-tubulin gene (TUB), and a portion of RNA polymerase second largest subunit (RPB2). The ITS, TUB, and RPB2 gene sequences of isolate WZU-OG1 were deposited in the GenBank database with acc. nos. ON332735, ON428245, and ON524171, respectively. BLASTn analysis respectively showed 561/561 (MH855125), 414/427 (KF296462), and 936/954 (JN121456) matching with Penicillium oxalicum CBS 219.30. A neighbor-joining phylogenetic analysis based on the concatenated nucleotide sequences (ITS, TUB, and RPB2) grouped this isolate in the Penicillium oxalicum species complex clade at 100% bootstrap support. To verify pathogenicity, 20 healthy mandarin fruit of cultivar Sanyang were superficially disinfested with 75% ethanol and then washed with distilled water. A conidial suspension of 1 × 105 conidia/ml from a 5-day-old culture of WZU-OG1 was injected into 10 fruits (10 μL per fruit). An equal number of fruits inoculated with sterile water were used as the negative control. The inoculated fruits were stored in a constant temperature incubator under the conditions of 28 ℃, 90% humidity, and incubated in a 12-h light/12-h dark cycle for 12 days. Symptoms similar to those on the naturally infected fruit began 5 days after inoculation, whereas no symptoms occurred on the controls. The experiment was repeated three times, and similar symptoms were observed in all diseased fruits. Then, the fungus was reisolated from these infected fruits and identified as P. oxalicum by the morphological and molecular methods described above. This is the first report of P. oxalicum causing postharvest mandarin decay and this study will enable us to rapidly diagnose this disease, identify the occurrence of this disease and develop adequate management strategies to control it in China.

Dendrobium officinale Kimura et Migo is a Chinese medicinal plant within the Orchidaceae. In September 2021, D. officinale seedlings in a greenhouse farm in the region of Wenzhou City (N28.11°, E120.98°), Zhejiang Province, China, were affected by stem rot. Symptoms initially occurred at the stem base with dark gray to black lesions, vascular discoloration, wilting and death. Approximately 30% of the surveyed plants were affected. To determine the causal agent, 10 symptomatic plant samples were collected. The necrotic tissue pieces (3×3 mm) from symptomatic stems were disinfected with 10% sodium hypochlorite for 1 min, rinsed three times with sterile water, and dried on sterile paper. Samples were then placed on potato dextrose agar (PDA), and incubated at 25℃ in the dark. After 3 days, reddish-white to yellow aerial mycelium with deep red pigments developed on PDA. A total of 15 single-spore isolates from all ten infected tissues were identified as Fusarium kyushuense based on morphological features (Aoki and O'Donnell 1998). DDO-S1 was chosen as a representative isolate for further study. Microconidia were ellipsoidal to clavate, 0 to 1 septate, and 5.2 to 17.6 × 2.3 to 4.7 μm (n = 100; length × width). Hyaline and straight or slightly curved macroconidia were observed with 3 to 5 septate, 32.4 to 51.7 × 3.9 to 5.3 μm (n = 100; length × width). In order to identify the isolate, a portion of RNA polymerase second largest subunit (RPB2) (Liu et al. 1999) and translation elongation factor-1α (TEF-1α) (Geiser et al. 2004) were amplified by PCR. The gene sequences from isolate DDO-S1 were deposited in the NCBI GenBank nucleotide database with accession numbers OL548912 and OL548913. BLASTn analysis showed highest similarity with F. kyushuense strain MRC 2534 99.9% (RPB2) and 99.2% (TEF-1α) nucleotide sequence identity, which indicated that the pathogen was F. kyushuense. A maximum-likelihood phylogenetic analysis based on multi-locus sequence analysis using MEGA X showed similar results (Kumar et al. 2018). Pathogenicity of this isolate was confirmed by following Koch's postulates. To verify pathogenicity, 30 healthy D. officinale seedlings (1-year-old) were used for inoculation tests. Fifteen surface sterilized stems were stab inoculated with 5 × 5 mm colonized agar discs of strain F. kyushuense DDO-S1 pierced at three points using a 1-mm sterile needle, and another 15 samples that were mock inoculated with sterile PDA disks as negative controls (Xiao et al. 2021). Each experimental seedling was inoculated with three agar disks from a colony of DDO-S1. Seedlings were placed in a humidified chamber (>95% relative humidity) at 25°C for 48 h after inoculation and kept in a growth chamber at 25°C and a daily 12 h photoperiod for 8 days. All inoculated stems showed symptoms identical to those observed in the field. No disease was observed on the controls. The pathogen was reisolated from all 15 diseased stems, and species identification was confirmed by the morphological and molecular methods described above. Fusarium kyushuense has been reported to cause diseases on a broad range of plants in China, such as tobacco (Wang et al. 2013), maize (Wang et al. 2014) and rice (Zhao et al. 2007). To the best of our knowledge, this is the first report of F. kyushuense on D. officinale in China. D. officinale is native to Wenzhou, and spread of the disease may seriously affect the local economy and food security. This report will help diagnose stem rot of D. officinale and provide a foundation for development of management tools.