Effect of Mosaic Knockout of Phytoene Desaturase Gene NtPDS on Biosynthesis of Carotenoids in Nicotiana tabacum L

• Published in: Russian journal of plant physiology Vol. 70; no. 6
• Main Authors: Nezhdanova, A. V., Slugina, M. A., Kulakova, A. V., Kamionskaya, A. M., Kochieva, E. Z., Shchennikova, A. V.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.12.2023; Springer Nature B.V
• Subjects: Biomedical and Life Sciences; Biosynthesis; Carotenoids; Chlorophyll; Colour; CRISPR; Desaturase; Desaturation; Editing; Flowering; Gene expression; Gene regulation; Genes; Genomes; Leaves; Life Sciences; MADS box proteins; Nicotiana tabacum; Photosynthesis; Phytoene synthase; Pigmentation; Plant Physiology; Plant Sciences; Plant tissues; Research Papers; Tobacco; Transcription; phytoene desaturase; biosynthesis of carotenoids; CRISPR-Cas9; gene expression
• DOI: 10.1134/S1021443723601271
• ISSN: 1021-4437

Carotenoids are essential participants in photosynthesis and photo protection as well as growth, development, and stress response in plants. Phytoene desaturase (PDS; EC 1.3.5.5) is an enzyme that catalyzes the first stage of desaturation of 15- cis -phytoene (a precursor to all carotenoids). In this work, we examined for the first time the effect of PDS knockout in the genome of Nicotiana tabacum L. using the CRISPR-Cas9 system on activity of downstream genes involved in biosynthesis of carotenoids. Nine transgenic lines of tobacco were obtained with a mosaic editing of gene NtPDS ; three versions of indels (350^351→ins^g#, 350^351→ins^t#, and t351→del(1nt)#) in the exon II resulting in the synthesis of a shortened non-functional version of the protein. The lines were characterized by spotted, green-white pigmentation of the leaves, altered flowering time and morphology as well as a reduced content of carotenoids and chlorophylls in the leaf tissue. A rise in the level of transcripts of phytoene synthase gene NtPSY2 was shown in late-flowering lines as compared to control material. Edited line L29 with the latest flowering showed a considerable increase in the level of transcripts of downstream structural genes of carotenogenesis. A reduction in the carotenoid content in the leaves with mosaic editing was accompanied by a decrease in the level of expression of MADS-box gene NtSEP1 , the product of which presumably participates in regulation of transcription of the carotenoid biosynthesis genes. The obtained results may be used for further studies of regulation of biosynthesis of carotenoids and apocarotenoids in Solanaceae.