文献类型：期刊文献

英文题名：MIR166a Affects the Germination of Somatic Embryos in Larixleptolepis by Modulating IAA Biosynthesis and Signaling Genes

作者：Li, Zhe-Xin[1] Zhang, Li-Feng[1] Li, Wan-Feng[1] Qi, Li-Wang[1] Han, Su-Ying[2]

通信作者：Han, SY[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：2017

卷号：36

期号：4

起止页码：889-896

外文期刊名：JOURNAL OF PLANT GROWTH REGULATION

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000413974900009)】；

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

语种：英文

外文关键词：MiR166a; HD-ZIP III; Larix leptolepis; Somatic embryo; Germination; IAA

摘要：The somatic embryogenic regeneration system is an ideal model system to study the regulation of early developmental processes and morphogenesis in gymnosperms. We have previously generated five larch (Larix leptolepis) LaMIR166a overexpression cell lines. The germination rates of mature somatic embryos in transgenic and wild-type (WT) lines were calculated and the results showed that overexpression of the miR166a precursor (LaMIR166a) markedly enhanced germination, especially in the a-3, a-4, and a-5 lines. The relative expression of LaMIR166a and miR166a in the LaMIR166a overexpression lines was higher than in the WT control line during the germination process, whereas the expression levels of LaHDZ31-34 increased markedly throughout germination, potentially as a result of feedback regulation of miR166. The effect of miR166a on auxin biosynthesis and signaling genes was also studied. During germination, mRNA levels of Nitrilase (LaNIT), Auxin response factor1 (LaARF1), and LaARF2 were markedly higher in LaMIR166a overexpressing lines. These results indicated that indole-3-acetic acid (IAA) synthesis is required for germination in L. leptolepis. Further exogenous application of IAA at different concentrations showed that 2 mg L-1 IAA clearly promoted germination, resulting in a 56% germination rate for L. leptolepis somatic embryos. This shows that IAA plays a vital role in controlling the germination ability of someatic embryos in L. leptolepis. Our results suggest that miR166a and LaHDZ31-34 have important roles in auxin biosynthesis and signaling during the germination of somatic embryos in L. leptolepis.