Root-shoot communication in tomato plants: cytokinin as a signal molecule modulating leaf photosynthetic activity

0522675 - ÚEB 2021 RIV GB eng J - Journal Article
Glanz-Idan, N. - Tarkowski, P. - Turečková, Veronika - Wolf, S.
Root-shoot communication in tomato plants: cytokinin as a signal molecule modulating leaf photosynthetic activity.
Journal of Experimental Botany. Roč. 71, č. 1 (2020), s. 247-257. ISSN 0022-0957. E-ISSN 1460-2431
Institutional support: RVO:61389030
Keywords : Solanum lycopersicum * Cytokinin * leaf development * photosynthesis * source–sink relationship * tomato * xylem
OECD category: Plant sciences, botany
Impact factor: 6.992, year: 2020
Method of publishing: Open access
https://academic.oup.com/jxb/article/71/1/247/5556948

Photosynthetic activity is affected by exogenous and endogenous inputs, including source-sink balance. Reducing the source to sink ratio by partial defoliation or heavy shading resulted in significant elevation of the photosynthetic rate in the remaining leaf of tomato plants within 3 d. The remaining leaf turned deep green, and its area increased by almost 3-fold within 7 d. Analyses of photosynthetic activity established up-regulation due to increased carbon fixation activity in the remaining leaf, rather than due to altered water balance. Moreover, senescence of the remaining leaf was significantly inhibited. As expected, carbohydrate concentration was lower in the remaining leaf than in the control leaves, however, expression of genes involved in sucrose export was significantly lower. These results suggest that the accumulated fixed carbohydrates were primarily devoted to increasing the size of the remaining leaf. Detailed analyses of the cytokinin content indicated that partial defoliation alters cytokinin biosynthesis in the roots, resulting in a higher concentration of trans-zeatin riboside, the major xylem-translocated molecule, and a higher concentration of total cytokinin in the remaining leaf. Together, our findings suggest that trans-zeatin riboside acts as a signal molecule that traffics from the root to the remaining leaf to alter gene expression and elevate photosynthetic activity.
Permanent Link: http://hdl.handle.net/11104/0307125