文献类型：期刊文献

英文题名：Over-expression of miR166a inhibits cotyledon formation in somatic embryos and promotes lateral root development in seedlings of Larix leptolepis

作者：Li, Zhe-Xin[1] Li, Shui-Gen[1] Zhang, Li-feng[1] Han, Su-ying[2] Li, Wan-Feng[1] Xu, Hai-yan[1] Yang, Wen-hua[1] Liu, Ya-li[1] Fan, Yan-ru[2] Qi, Li-Wang[1]

通信作者：Qi, LW[1]

机构：[1]Chinese Acad Forestry, Res Inst Forestry, State Key Lab Tree Genet & Breeding, Beijing 100091, Peoples R China;[2]Chinese Acad Forestry, Res Inst Forest Ecol Environm & Protect, Beijing 100091, Peoples R China

年份：2016

卷号：127

期号：2

起止页码：461-473

外文期刊名：PLANT CELL TISSUE AND ORGAN CULTURE

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000387168500017)】；

基金：This work was supported by the National Natural Science Foundation of China (31330017) and the National High Technology Research and Development Program of China (2013AA102704).

语种：英文

外文关键词：MiR166a; Larix leptolepis; Somatic embryos; Cotyledon; Lateral roots

摘要：Somatic embryo (SE) regeneration is an ideal experimental system to realize rapid propagation of excellent clones and genetic improvement for perennial gymnosperms. In the present study, genes encoding the miRNA166 precursor were identified and LamiR166a was successfully transformed into the gymnosperm Larix leptolepis (L. leptolepis) and five LamiR166a over-expressed embryonic cell lines were screened out as stable embryo masses. As expected, the targets of miR166a, LaHDZ31-34, were all down-regulated in transgenic lines according to qRT-PCR results. The results showed that the percentage of normal SEs with 4-7 cotyledons was 77.0 % in wild type (WT) lines, but was reduced to 60.3 % in the pSuper::MIR166a lines with "cup-shaped" embryos comprised 7.0 % of WT and 20.7 % of transgenic embryos. Microscopic observation further showed that the intermediate region surrounded by the cotyledons was larger than in the control, with no upward bulge of the shoot apical meristem (SAM). The expression pattern of the two meristem marker genes CLAVATA (CLV) and WUSCHEL-related homeobox (WOX) were investigated. The results showed that the expression levels of WOX were three times higher in transgenic lines than in WT samples, which suggest that miR166a may indirectly regulate SAM development by directly affecting WOX expression. Besides, overexpression of LamiR166a clearly increased the rooting rate and promoted lateral root formation in L. leptolepis seedlings. These results may provide new insights into the regulatory role of miR166 in gymnosperms, and also new applications for forestry production in practice.