The manipulation of cytokinin levels by senescence-regulated expression of the Agrobacterium tumefaciens ipt gene through its control by the Arabidopsis SAG12 (senescence-associated gene 12) promoter is an efficient tool for the prolongation of leaf photosynthetic activity which potentially can affect plant productivity. In the present study, the efficiency of this approach was tested on wheat (Triticum aestivum L.)—a monocarpic plant characterized by a fast switch from vegetative to reproductive growth, and rapid translocation of metabolites from leaves to developing grains after anthesis. When compared with the wild-type (WT) control plants, the SAG12::ipt wheat plants exhibited delayed chlorophyll degradation only when grown under limited nitrogen (N) supply. Ten days after anthesis the content of chlorophyll and bioactive cytokinins of the first (flag) leaf of the transgenic plants was 32% and 65% higher, respectively, than that of the control. There was a progressive increase in nitrate influx and nitrate reductase activity. However, the SAG12::ipt and the WT plants did not show differences in yield-related parameters including number of grains and grain weight. These results suggest that the delay of leaf senescence in wheat also delays the translocation of metabolites from leaves to developing grains, as indicated by higher accumulation of (¹⁵N-labelled) N in spikes of control compared with transgenic plants prior to anthesis. This delay interferes with the wheat reproductive strategy that is based on a fast programmed translocation of metabolites from the senescing leaves to the reproductive sinks shortly after anthesis.

The international symposium “Auxins and Cytokinins in Plant Development” (ACPD), which is held every 4–5 years in Prague, Czech Republic, is a meeting of scientists interested in the elucidation of the action of two important plant hormones—auxins and cytokinins. It is organized by a group of researchers from the Laboratory of Hormonal Regulations in Plants at the Institute of Experimental Botany, the Czech Academy of Sciences. The symposia already have a long tradition, having started in 1972. Thanks to the central role of auxins and cytokinins in plant development, the ACPD 2018 symposium was again attended by numerous experts who presented their results in the opening, two plenary lectures, and six regular sessions, including two poster sessions. Due to the open character of the research community, which is traditionally very well displayed during the meeting, a lot of unpublished data were presented and discussed. In this report, we summarize the contributions in individual sessions that attracted our attention.