Effects of biotic stress caused by Potato virus Y on photosynthesis in ipt transgenic and control Nicotiana tabacum L

• Published in: Plant science (Limerick) Vol. 171; no. 5; pp. 607 - 616
• Main Authors: Synková, Helena, Semorádová, Šárka, Schnablová, Renáta, Müller, Karel, Pospíšilová, Jana, Ryšlavá, Helena, Malbeck, Jiří, Čeřovská, Noemi
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier Ireland Ltd 01.11.2006; Elsevier Science
• Subjects: alkyl (aryl) transferases; bacterial proteins; Biological and medical sciences; chlorophyll; Cytokinins; enzyme activity; Fundamental and applied biological sciences. Psychology; gas exchange; ipt; isopentenyltransferase; Metabolism; Nicotiana tabacum; non-photochemical quenching; Photosynthesis; Photosynthesis, respiration. Anabolism, catabolism; photosystem II; Plant physiology and development; plant pigments; plant stress; plant viruses; Potato virus Y; quantum yield; ribulose-bisphosphate carboxylase; Solanum tuberosum; stomata; tobacco; transgenes; transgenic plants; Transgenic tobacco; viral proteins; Transgenic tobacco; Cytokinins; Photosynthesis; ipt; Potato virus Y; Dicotyledones; Angiospermae; Spermatophyta; Solanaceae; Nicotiana tabacum; Cytokinin; Stress
• ISSN: 0168-9452; 1873-2259
• DOI: 10.1016/j.plantsci.2006.06.002

We studied the effect of biotic stress caused by Potato virus Y NTN (PVY) on photosynthesis in transgenic P ssu- ipt tobacco overproducing endogenous cytokinins (CK) in comparison with control (non-transformed) plants. Both control and transgenic tobacco were grown as rooted or grafted plants. Content of viral protein increased significantly in control tobacco within ca. 18 days after inoculation, whereas transgenic plants exhibited much lower accumulation. This corresponded also with the presence of visible symptoms of PVY infection; while they were always present in control, rooted tobacco, they never developed in transgenic grafts. Contents of CKs (mostly in the forms of N- and/or O-glucosides) increased in all infected plants except transgenic grafts, where the highest amount of CKs was found already prior the inoculation. The photosynthetic rate ( P N) was significantly inhibited by PVY infection in control and transgenic rooted plants, while both grafted types were less affected. Reduction of P N was caused not only by stomata closure, but also by the decrease of ribulose-1,5-bisphosphate carboxylase/oxygenase activity, contents of chlorophylls and xanthophyll cycle pigments, and activity of photosystem II (PSII). The negative effect on PS II was promoted by high irradiance treatment particularly in both rooted types infected by PVY.