Effect of heat stress on plants expressing genes of hybrid cyanobacterial Δ-9- and Δ-12-acyl-lipid desaturases

Abstract

Aims. Glycerolipid fatty acids desaturation is one of the most important reactions in plant cell determining parameters of cell membrane. Introduction of heterologous desaturase genes is expected to improve plant cold resistance, but may affect their heat tolerance. We studied physiological characteristics of transgenic Nicotiana tabacum plants with modified fatty acid patterns expressing hybrid genes of desaturase  desC (Δ9) Synechoccus vulcanus and desA (Δ12) Synechocystis sp. PCC 6803, fused with the reporter gene of thermostable lichenase licBM3 Clostridium thermocellum, controlled by the constitutive 35S promoter. Methods. We have determined electrolyte levels and superoxide dismutase activity of leaf explants at elevated temperatures (cultivation at 42⁰C for 36 h). Results. Analysis of these measurements showed no significant differences in control and experimental plants. Conclusions. Expression of cyanobacterial desaturase genes did not affect the heat tolerance of transgenic plants.

Keywords: acyl-lipid desaturase, cyanobacteria, desC (Δ9) Synechoccus vulsanus, desA (Δ12) Synechocystis sp., hyperthermal stress.