文献类型：期刊文献

英文题名：LaMIR166a-mediated auxin biosynthesis and signalling affect somatic embryogenesis in Larix leptolepis

作者：Li, Zhe-Xin[1,2] Fan, Yan-Ru[1] Dang, Shao-Fei[1] Li, Wan-Feng[1] Qi, Li-Wang[1] Han, Su-ying[3]

第一作者：Li, Zhe-Xin

通信作者：Qi, LW[1];Han, SY[2]

机构：[1]Chinese Acad Forestry, Res Inst Forestry, State Key Lab Tree Genet & Breeding, State Forestry Adm,Key Lab Tree Breeding & Cultiv, Beijing 100091, Peoples R China;[2]Chongqing Univ Arts & Sci, Collaborat Innovat Ctr Special Plant Ind, Chongqing Key Lab Econ Plant Biotechnol, Chongqing 402160, Peoples R China;[3]Chinese Acad Forestry, Res Inst Forest Ecol Environm & Protect, Beijing 100091, Peoples R China

年份：2018

卷号：293

期号：6

起止页码：1355-1363

外文期刊名：MOLECULAR GENETICS AND GENOMICS

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000452375700003)】；

基金：This work was supported by the National Transgenic Major Program of China (2018ZX08022001), the National Science Foundation of China (31330017 and 31200464), and the Basic Research Fund of RIF (grant no. RIF2014-07).

语种：英文

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

摘要：Somatic embryogenesis (SE) involves complex molecular signalling pathways. Understanding molecular mechanism of SE in Larix leptolepis (L. leptolepis) can aid research on genetic improvement of gymnosperms. Previously, we obtained five LaMIR166a (miR166a precursor) -overexpression embryonic cell lines in the gymnosperm Larix leptolepis. The proliferation rates of pro-embryogenic masses in transgenic and wild-type lines were calculated. Overexpression of the miR166a precursor LaMIR166a led to slower proliferation. When pro-embryogenic masses were transferred to maturation medium, the relative expression of LaMIR166a and miR166a in the LaMIR166a-overexpression lines was higher than in the wild-type during SE, while LaHDZ31-34 expression levels also increased without negative control by miR166, suggesting that regulation of HD-ZIP III by miR166a exits stage-specific characteristics. The key indole-3-acetic acid (IAA) biosynthetic gene Nitrilase of L. leptolepis (LaNIT) was identified and the effects of miR166a on auxin biosynthesis and signalling genes were studied. During SE, LaNIT, Auxin response factor1 (LaARF1) and LaARF2 mRNA levels and IAA contents were markedly higher in LaMIR166a-overexpression lines, which revealed lower deformity rate of embryos, indicating endogenous IAA synthesis is required for somatic embryo maturation in L. leptolepis. Additionally, the IAA biosynthesis and signalling genes showed similar expression patterns to LaHDZ31-34, suggesting HD-ZIP III genes have a positive regulatory effect on LaNIT. Our results suggest miR166a and LaHDZ31-34 have important roles in auxin biosynthesis and signalling during SE, which might determine if the somatic embryo normally developed to mature in L. leptolepis.