文献类型： 外文期刊

作者： Zhao, Xiaolan ¹ ; Zhang, Jianxia ² ; Chen, Chunli ¹ ; Yang, Jingze ¹ ; Zhu, Haiyan ¹ ; Liu, Min ¹ ; Lv, Fubing ³ ;

作者机构： 1.South China Agr Univ, Guangdong Key Lab Innovat Dev & Utilizat Forest P, Guangzhou 510642, Guangdong, Peoples R China

2.Chinese Acad Sci, Key Lab South China Agr Plant Genet & Breeding, South China Bot Garden, Guangzhou 510650, Guangdong, Peoples R China

3.Guangdong Acad Agr Sci, Guangdong Key Lab Ornamental Plant Germplasm Inno, Environm Hort Res Inst, Guangzhou 510640, Guangdong, Peoples R China

关键词： Root transcriptome;Digital gene expression;Plant mycorrhizal symbiosis;Cymbidium hybridum;Epulorhiza repens ML01;Umbelopsis nana ZH3A-3

期刊名称：BMC GENOMICS （ 影响因子：3.969； 五年影响因子：4.478 ）

ISSN： 1471-2164

年卷期： 2014 年 15 卷

页码：

收录情况： SCI

摘要： Background: The Orchidaceae is one of the largest families in the plant kingdom and orchid mycorrhizae (OM) are indispensable in the life cycle of all orchids under natural conditions. In spite of this, little is known concerning the mechanisms underlying orchid-mycorrhizal fungi interactions. Our previous work demonstrated that the non-mycorrhizal fungus Umbelopsis nana ZH3A-3 could improve the symbiotic effects of orchid mycorrhizal fungus Epulorhiza repens ML01 by co-cultivation with Cymbidium hybridum plantlets. Thus, we investigated the C. hybridum transcript profile associated with different beneficial fungi. Results: More than 54,993,972 clean reads were obtained from un-normalized cDNA library prepared from fungal-and mock-treated Cymbidium roots at four time points using RNA-seq technology. These reads were assembled into 16,798 unique transcripts, with a mean length of 1127 bp. A total of 10,971 (65.31%) sequences were annotated based on BLASTX results and over ninety percent of which were assigned to plant origin. The digital gene expression profiles in Cymbidium root at 15 days post inoculation revealed that 1674, 845 and 1743 genes were sigificantly regulated in response to ML01, ZH3A-3 and ML01+ ZH3A-3 treatments, respectively. Twenty-six genes in different regulation patterns were validated using quantitative RT-PCR. Our analysis showed that general defense responses were co-induced by three treatments, including cell wall modification, reactive oxygen species detoxification, secondary biosynthesis and hormone balance. Genes involved in phosphate transport and root morphogenesis were also detected to be up-regulated collectively. Among the OM specifically induced transcripts, genes related to signaling, protein metabolism and processing, defense, transport and auxin response were identifed. Aside from these orchid transcripts, some putative fungal genes were also identified in symbiotic roots related to plant cell wall degradation, remodeling the fungal cell wall and nutrient transport. Conclusion: The orchid root transcriptome will facilitate our understanding of orchid - associated biological mechanism. The comparative expression profiling revealed that the transcriptional reprogramming by OM symbiosis generally overlapped that of arbuscular mycorrhizas and ectomycorrhizas. The molecular basis of OM formation and function will improve our knowledge of plant-mycorrhzial fungi interactions, and their effects on plant and fungal growth, development and differentiation.