Light conditions and cold induced changes in the expression of Solanum tuberosum L. ω3-desaturase genes

The effects of various light conditions (WL - white light, D - darkness, RL - red light, WL + RL - white light + red light) on the transcription and translation processes of ω3-desaturase genes in Solanum tuberosum L. during cold acclimation were studied. Plants grown at a temperature of 22 °C and WL were used as controls. It has been shown that the level of transcripts of the FAD3-1 and FAD3-2 genes of the endoplasmic reticulum ω3-desaturases decreased significantly under all light conditions during cold acclimation. The level of transcripts FAD7 gene of the chloroplast ω3-desaturase remained at the level of the uncooled control under WL and WL + RL conditions. Cold temperatures showed different effects on the translation of potato ω3-desaturases localized in chloroplasts and the endoplasmic reticulum. The level of FAD7 mRNA associated with monosomes increased significantly under all lighting conditions compared to the control, while the level of FAD3-1 and FAD3-2 mRNA did not exceed the control values. The levels of FAD3-1 and FAD3-2 mRNAs associated with polysomes increased significantly only under RL, while FAD7 mRNA levels increased under WL and WL + RL as well. An increase in the content of 18:3 FAs, a product of ω-3 desaturase synthesis, occurred only under WL and WL + RL lighting conditions during acclimation to cold temperatures. We consider that the accumulation of 18:3 fatty acids during the cold acclimation of Solanum tuberosum L. occurs mainly due to the maintenance of the constitutive level of transcription and activation of translation in the monosome and polysome of ω3-desaturase FAD7, localized in chloroplasts.