GAJDOŠOVÁ, Silvia, SPÍCHAL, Lukáš, KAMÍNEK, Miroslav, HOYEROVÁ, Klára, NOVÁK, Ondřej, DOBREV, Petre, GALUSZKA, Petr, KLÍMA, Petr, GAUDINOVÁ, Alena, ŽIŽKOVÁ, Eva, HANUŠ, Jan, DANČÁK, M., TRÁVNÍČEK, B., PEŠEK, Bedřich, KRUPIČKA, M., VAŇKOVÁ, Radomíra, STRNAD, Miroslav, MOTYKA, Václav. Distribution, biological activities, metabolism, and the conceivable function of cis-zeatin-type cytokinins in plants. Journal of Experimental Botany. 2011, 62(8), 2827-2840. ISSN 0022-0957. E-ISSN 1460-2431

The comprehensive screen through the land plants is presented suggesting that cytokinins (CKs) of cis-zeatin (cisZ)-type occur generally in plant kingdom. Changing levels of trans-zeatin (transZ) and cisZ during the Arabidopsis ontogeny shows that levels of the two Z isomers can significantly differ during the plant lifespan with cisZ CKs prevalence in developmental stages associated with limited growth. cisZ and transZ have different metabolic fate in oat and tobacco and cisZ is a preferred substrate of some Arabidopsis cytokinin oxidase/dehydrogenase (CKX) isoforms. Any cis-trans isomerization wasn’t observed. Survey of employed bioassays illustrates ability of high doses of cisZ-type CKs to induce various physiological responses and CK signaling. These data argue against the image of cisZ-type CKs as the non-active or weakly active natural adjuncts to the trans isomers suggesting their conceivable function as delicate regulators of CK responses in growth-limiting conditions.