College of Landscape Architecture, Northeast Forestry University, Harbin, 150040, China.
College of Traditional Chinese Medicine, Jilin Agriculture Science and Technology University, Jilin, 132000, China.
Plant Physiol Biochem. 2021 Nov;168:17-26. doi: 10.1016/j.plaphy.2021.09.035. Epub 2021 Sep 28.
The conserved microRNA396 (miR396) is involved in growth, development, and abiotic stress responses in a variety of plants by regulating target genes. Here, we obtained transgenic Chrysanthemum indicum (C. indicum) overexpressing the cin-miR396a gene. The transgenic plants (TGs) had longer internodes and fewer epidermal hairs in contrast with the wild-type (WT) control. cin-miR396a overexpression in C. indicum reduced salt tolerance and drought tolerance. After salt and drought stress compared with WT plants, the transgenic C. indicum exhibited a relative decrease in leaf water content, and the leaf free proline content, also exhibited a relative increase, in the leaf conductivity and leaf Malondialdehyde content, while the total chlorophyll content did not differ significantly from WT, and the Na/K ratio in the roots of transgenic C. indicum increased after salt stress. We also identified two target genes of cin-miR396a, CiGRF1 and CiGRF5, whose expression was induced by salt and drought treatments and suppressed in transgenic C. indicum. Taken together, our results reveal a unique role for the regulatory module of miR396a-GRFs in C. indicum development and response to abiotic stresses. cin-miR396a plays a negative regulatory role in C. indicum in response to salt and drought stresses.
保守的 microRNA396（miR396）通过调节靶基因参与多种植物的生长、发育和非生物胁迫反应。在这里，我们获得了过表达 cin-miR396a 基因的转基因菊花（C. indicum）。与野生型（WT）对照相比，转基因植物（TGs）的节间更长，表皮毛更少。在菊花中过表达 cin-miR396a 会降低其耐盐性和耐旱性。与 WT 植物相比，在盐和干旱胁迫后，转基因菊花的叶片水分含量相对降低，叶片游离脯氨酸含量相对增加，叶片电导率和叶片丙二醛含量相对增加，而总叶绿素含量与 WT 无显著差异，盐胁迫后转基因菊花根系中的 Na/K 比值增加。我们还鉴定了 cin-miR396a 的两个靶基因 CiGRF1 和 CiGRF5，它们的表达受到盐和干旱处理的诱导，并在转基因菊花中受到抑制。综上所述，我们的研究结果揭示了 miR396a-GRFs 调控模块在菊花发育和应对非生物胁迫中的独特作用。cin-miR396a 在菊花应对盐和干旱胁迫中发挥负调控作用。
