title: An efficient genetic manipulation protocol for Ustilago esculenta.
abstract: Ustilago esculenta grows within the flowering stem of the aquatic grass Zizania latifolia, resembling a fungal endophyte. The fungus colonizes Z. latifolia and induces swelling which results in the formation of galls near the base of the plant. Due to their unique flavor and textures these galls are considered as a delicacy in southern China. Efficient genetic manipulation is required to determine the relationship between U. esculenta and Z. latifolia. In this study, we report a protoplast-based transformation system for this unique fungal species. We have explored various factors (enzyme digesting conditions, osmotic pressure stabilizers, vectors and selection agents) that might impact protoplast yield and high frequencies of transformation. A haploid strain (UeT55) of U. esculenta was found to produce higher yields of protoplasts when treating with 15 mg mL(-1) lywallzyme in a sucrose-containing solution at 30°C for 3 h. The transformation frequencies were higher when fungal strain was transformed with a linear plasmid harboring hygromycin or carboxin resistance gene and regenerated on a sucrose-containing medium. A UeICL gene (coding isocitrate lyase) was disrupted and an EGFP (coding enhanced green fluorescent protein) gene was overexpressed successfully in the UeT55 strain using the developed conditions. The genetic manipulation system reported in this study will open up new opportunities for forward and reverse genetics in U. esculenta.
authors.affiliation: Zhejiang Provincial Key Laboratory of Biometrology and Inspection & Quarantine, College of Life Sciences, China Jiliang University, Hangzhou, Zhejiang 310018, China.
authors.forename: Jiajia
authors.initials: J
authors.lastname: Yu
authors.affiliation: Zhejiang Provincial Key Laboratory of Biometrology and Inspection & Quarantine, College of Life Sciences, China Jiliang University, Hangzhou, Zhejiang 310018, China.
authors.forename: Yafen
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Zhejiang Provincial Key Laboratory of Biometrology and Inspection & Quarantine, College of Life Sciences, China Jiliang University, Hangzhou, Zhejiang 310018, China.
authors.forename: Haifeng
authors.initials: H
authors.lastname: Cui
authors.affiliation: Zhejiang Provincial Key Laboratory of Biometrology and Inspection & Quarantine, College of Life Sciences, China Jiliang University, Hangzhou, Zhejiang 310018, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Hu
authors.affiliation: Zhejiang Provincial Key Laboratory of Biometrology and Inspection & Quarantine, College of Life Sciences, China Jiliang University, Hangzhou, Zhejiang 310018, China.
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Yu
authors.affiliation: Zhejiang Provincial Key Laboratory of Biometrology and Inspection & Quarantine, College of Life Sciences, China Jiliang University, Hangzhou, Zhejiang 310018, China zhye@cjlu.edu.cn.
authors.forename: Zihong
authors.initials: Z
authors.lastname: Ye
mesh_terms: D002261:Carboxin / Q000494:pharmacology; D002473:Cell Wall / Q000378:metabolism; D002934:Cinnamates / Q000494:pharmacology; D004798:Enzymes / Q000378:metabolism; D005821:Genetic Techniques; D006238:Haploidy; D006921:Hygromycin B / Q000031:analogs & derivatives / Q000494:pharmacology; D007522:Isocitrate Lyase / Q000235:genetics; D010957:Plasmids / Q000235:genetics; D011523:Protoplasts / Q000502:physiology*; D014170:Transformation, Genetic; D014588:Ustilago / Q000187:drug effects / Q000235:genetics* / Q000502:physiology
chemical_list: D002934:Cinnamates; D004798:Enzymes; D006921:Hygromycin B; C026273:hygromycin A; D002261:Carboxin; D007522:Isocitrate Lyase
keywords: Ustilago esculenta; Zizania latifolia; protoplast; transformation