Soil salinization and aridification are swiftly engulfing the limited land resources on which humans depend, restricting agricultural production. HMGR is important in terpenoid biosynthesis, and terpenoids are involved in plant growth, development, and responses to environmental stresses. This study aimed providing some guidance for obtaining salt and drought resistant poplar.,Protein expression system was used to obtain PtHMGR protein, and high performance liquid chromatography was used to detect the activity of PtHMGR protein in vitro. In addition, a simplified version of the leaf infection method was used for transformation of Nanlin895 poplar (Populus× euramericana cv.). qRT-PCR was used to identify expres... More
Soil salinization and aridification are swiftly engulfing the limited land resources on which humans depend, restricting agricultural production. HMGR is important in terpenoid biosynthesis, and terpenoids are involved in plant growth, development, and responses to environmental stresses. This study aimed providing some guidance for obtaining salt and drought resistant poplar.,Protein expression system was used to obtain PtHMGR protein, and high performance liquid chromatography was used to detect the activity of PtHMGR protein in vitro. In addition, a simplified version of the leaf infection method was used for transformation of Nanlin895 poplar (Populus× euramericana cv.). qRT-PCR was used to identify expression levels of genes.,PtHMGR catalyzed a reaction involving HMG-CoA and NADPH to form mevalonate. Overexpression of PtHMGR in Populus × euramericana cv Nanlin895 improved drought and salinity tolerance. In the presence of NaCl and PEG6000, the rates of rooting and survival of PtHMGR-overexpressing poplars were higher than those of wild type poplars. The transgenic lines also exhibited higher proline content, and peroxidase and superoxide dismutase activities, and a lower malondialdehyde level under osmotic stress. In addition, the expression of reactive oxygen species scavenging and formation-related genes was altered by osmotic stress. Moreover, the effect of osmotic stress on the transcript levels of stress-related genes differed between the transgenic and wild type poplars.,PtHMGR catalyzed a reaction involving HMG-CoA and NADPH to form mevalonate in vitro. Overexpression of PtHMGR promoted root development, increased the expression of ROS scavenging-related genes, decreased the expression of ROS formation-related genes, and increased the activity of antioxidant enzymes in the transgenic poplars, enhancing their tolerance to osmotic stress. In addition, overexpression of PtHMGR increased expression of the stress-related genes KIN1, COR15, and AAO3, and decreased that of ABI, MYB, MYC2, and RD22, enhancing the stress resistance of poplar.,© The Author(s) 2019. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
