Role of Lipids of the Evergreen Shrub Ephedra monosperma in Adaptation to Low Temperature in the Cryolithozone.

Lipids are the fundamental components of cell membranes and they play a significant role in their integrity and fluidity. The alteration in lipid composition of membranes has been reported to be a major response to abiotic environmental stresses. Seasonal dynamics of membrane lipids in the shoots of Ephedra monosperma J.G. Gmel. ex C.A. Mey. growing in natural conditions of permafrost ecosystems was studied using HPTLC, GC-MS and ESI-MS. An important role of lipid metabolism was established during the autumn-winter period when the shoots of the evergreen shrub were exposed to low positive (3.6 °C), negative (-8.3 °C) and extremely low temperatures (-38.4 °C). Maximum accumulation of phosphatidic acid (PA), the amount of which is times times greater than the sum of phosphatidylcholine and phosphatidylethanolamine (PC + PE) was noted in shoots of E. monosperma in the summer-autumn period. The autumn hardening period (3.6 °C) is accompanied by active biosynthesis and accumulation of membrane lipids, a decrease of saturated 34:1 PCs, 34:1 PEs and 34:1 PAs, and an increase in unsaturated long-chain 38:5 PEs, 38:6 PEs, indicating that the adaptation of E. monosperma occurs not at the level of lipid classes but at the level of molecular species. At a further decrease of average daily air temperature in October (-8.3 °C) a sharp decline of PA level was registered. At an extreme reduction of environmental temperature (-38.4 °C) the content of non-bilayer PE and PA increases, the level of unsaturated fatty acids (FA) rises due to the increase of C18:2(Δ9,12) and C18:3(Δ9,12,15) acids and the decrease of C16:0 acids. It is concluded that changes in lipid metabolism reflect structural and functional reorganization of cell membranes and are an integral component of the complex process of plant hardening to low temperatures, which contributes to the survival of E. monosperma monocotyledonous plants in the extreme conditions of the Yakutia cryolithozone.

Characteristic and phylogenetic analyses of chloroplast genome for Ephedra monosperma (Ephedraceae), an important medicinal species.

Ephedra monosperma is an important medicinal plant of Ephedra (Ephedraceae). The complete chloroplast genome of E. monosperma was assembled from Illumina pair-end sequence reads. The whole chloroplast (cp) genome is 109,548 bp in length and presents a quadripartite structure consisting of two copies of inverted repeat (IR) regions (20,398) separated by a large single copy (LSC) region (60,674 bp) and a small single copy (SSC) region (8078 bp). The cp genome of E. monosperma encodes a total of 118 genes, including 73 protein-coding genes, 37 tRNA genes and 8 rRNA genes. The overall GC content of E. monosperma cp genome is 36.6%. A maximum likelihood (ML) phylogenetic analysis revealed that E. monosperma was close to Ephedra equisetina. The ML tree also showed Ephedraceae appeared more closely related to Gnetaceae than to the other families in Gymnospermae.