Effects of cor15a-IPT gene expression on leaf senescence in transgenic Petuniaxhybrida and Dendranthemaxgrandiflorum

Khodakovskaya, M.; Li, Y.; Li, J.; Vaňková, Radomíra; Malbeck, Jiří; McAvoy, R.
JOURNAL OF EXPERIMENTAL BOTANY 56 [414]: 1165-1175, 2005

Klíčová slova: Cold-inducible promoter; cytokinins; ipt expression
Abstrakt: To prevent leaf senescence of young transplants or excised shoots during storage under dark and cold conditions, the cytokinin biosynthetic gene isopentenyl transferase (ipt) was placed under the control of a cold-inducible promoter cor15a from Arabidopsis thaliana and introduced into Petuniaxhybrida ‘Marco Polo Odyssey’ and Dendranthemaxgrandiflorum (chrysanthemum) ‘Iridon’. Transgenic cor15a-ipt petunia and chrysanthemum plants and excised leaves remained green and healthy during prolonged dark storage (4 weeks at 25 °C) after an initial exposure to a brief cold-induction period (4 °C for 72 h). However, cor15a-ipt chrysanthemum plants and excised leaves that were not exposed to a cold-induction period, senesced under the same dark storage conditions. Regardless of cold-induction treatment, leaves and plants of non-transformed plants senesced under prolonged dark storage. Analysis of ipt expression indicated a marked increase in gene expression in intact transgenic plants as well as in isolated transgenic leaves exposed to a short cold-induction treatment prior to dark storage. These changes correlated with elevated concentrations of cytokinins in transgenic leaves after cold treatment. Cor15a-ipt transgenic plants showed a normal phenotype when grown at 25 °C.
Autoři z ÚEB: Jiří Malbeck, Radomíra Vaňková