Analysis of the Expression Patterns and Function of IDD Transcription Factors in Rice Roots
|School||Huazhong Agricultural University|
|Keywords||rice root IDD transcription factor expression analysis and function identification|
Root development in rice is essential for its aerial part development and its ability to cope with various environmental conditions such as salinity, flooding and drought. Cortex is the basic structure of root, originating from meristem, comprised of parenchyma cells, and replaces epidermal as a guard, simultaneously controlling the nutrition transportation. Unlike the dicotyledonous model plant Arabidopsis thaliana which has only a single root cortex layer, rice roots have many layers of cortex cells. In Arabidopsis thaliana root, the basic ground initials, by asymmetric dividision, form the first cells of the cortex and endodermal lineages. But how multiple cortex layers are formed and developed in rice roots remains unknown.To address this question, in this study, based on researches on root of Arabidopsis thaliana, we analyzed the expression patterns and function of IDD transcription factors in rice roots, by mean of In Situ Hybridization, Gene Chip, analysis of transgenic plants from promoter fusion and gain-of-function mutants, gain-of-function mutants. This result will allow us to identify novel factors and gene regulatory network for rice root development. The main results are as follows:1. Analysis of the expression profile of rice IDDs from CREP, and combinating with results from shaihai genechip data indicate:(1) Various expression patterns of OsIDD transcription factors ranged from expression in only one tissue, in multiple tissues, and simultaneously in majority of the tissues.(2) Treated by NAA, GA3 and KT, the expression of OsIDD3,OsIDD6,OsIDD12 and OsIDD13 had no evident difference, while OsIDD7, OsIDD7 and OsIDD15 were sensitive to at least one kind of phytohormone.(3) OsIDD3,OsIDD6,OsIDD12, OsIDD13 and OsIDD15 had little sensitivity to light and dark treatments.2. Construction of 14 transformation vectors in this study,3 of which were over expression vetors,5 of which were promoter fusion vectors and 7 of which were amiRNA vectors, had been transformation, and 9 of which had get transgenic plants. 3. The results of In Situ Hybridization reveal that the expression patterns of OsIDD3, OsIDD6 and OsIDD7 were different, while expression in cortex and stele was common.4. Histochemical assay of leaf, coleoptile and root showed that expression of OsIDD7 was in leaf vein, tip of coleoptile, root cortex and root stele, in line with the result of In Situ Hybridization.