title: The maturation zone is an important target of Piriformospora indica in Chinese cabbage roots.
abstract: The mutualistic symbiont Piriformospora indica exhibits a great potential in agriculture. The interaction between P. indica and Chinese cabbage (Brassica campestris cv. Chinensis) results in growth and biomass promotion of the host plant and in particular in root hair development. The resulting highly bushy root phenotype of colonized Chinese cabbage seedlings differs substantially from reports of other plant species, which prompted the more detailed study of this symbiosis. A large-scale expressed sequence tag (EST) data set was obtained from a double-subtractive EST library, by subtracting the cDNAs of Chinese cabbage root tissue and of P. indica mycelium from those of P. indica-colonized root tissue. The analysis revealed ~700 unique genes rooted in 141 clusters and 559 singles. A total of 66% of the sequences could be annotated in the NCBI GenBank. Genes which are stimulated by P. indica are involved in various types of transport, carbohydrate metabolism, auxin signalling, cell wall metabolism, and root development, including the root hair-forming phosphoinositide phosphatase 4. For 20 key genes, induction by fungal colonization was confirmed kinetically during the interaction by real-time reverse transcription-PCR. Moreover, the auxin concentration increases transiently after exposure of the roots to P. indica. Microscopic analyses demonstrated that the development of the root maturation zone is the major target of P. indica in Chinese cabbage. Taken together, the symbiotic interaction between Chinese cabbage and P. indica is a novel model to study root growth promotion which, in turn, is important for agriculture and plant biotechnology.
authors.affiliation: College of Life Science, Yangtze University, Jingzhou, Hubei 434025, China.
authors.forename: Sheqin
authors.initials: S
authors.lastname: Dong
authors.forename: Zhihong
authors.initials: Z
authors.lastname: Tian
authors.forename: Peng Jen
authors.initials: PJ
authors.lastname: Chen
authors.forename: Rajendran
authors.initials: R
authors.lastname: Senthil Kumar
authors.forename: Chin Hui
authors.initials: CH
authors.lastname: Shen
authors.forename: Daguang
authors.initials: D
authors.lastname: Cai
authors.forename: Ralf
authors.initials: R
authors.lastname: Oelmüllar
authors.forename: Kai Wun
authors.initials: KW
authors.lastname: Yeh
mesh_terms: D001487:Basidiomycota / Q000254:growth & development / Q000502:physiology*; D018533:Biomass; D001937:Brassica / Q000235:genetics / Q000254:growth & development* / Q000382:microbiology*; D002681:China; D015169:Colony Count, Microbial; D030541:Databases, Genetic; D020224:Expressed Sequence Tags; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant / Q000235:genetics; D007210:Indoleacetic Acids / Q000378:metabolism; D008954:Models, Biological; D058977:Molecular Sequence Annotation; D018517:Plant Roots / Q000033:anatomy & histology / Q000235:genetics / Q000254:growth & development* / Q000382:microbiology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D015203:Reproducibility of Results; D015854:Up-Regulation / Q000235:genetics
chemical_list: D007210:Indoleacetic Acids; D012333:RNA, Messenger
keywords: Chinese cabbage; Piriformospora indica; growth and biomass promotion; mutualistic symbiosis; root maturation zone; subtractive EST library