Klotz, M. G. and Erdei, L. 1988. Effect of tentoxin on K+ transport in winter wheat seedlings of different K+‐status. The influence of the phytoeffective mycotoxin, tentoxin, [cyclo‐(L‐leucyl‐N‐methyltrans‐dehydronhenyl‐alanyl‐glycyl‐N‐methyl‐L‐alanyl)] (in K+ uptake and on translocation of K+ from roots to shoot was studied in 14‐day‐old winter wheat plants (Triticum aestivum L. cv. Martonvásári‐8) grown at different levels of K+ supply. For comparison, the effects of 2,4‐dinilrophcnol and valinomycin were also investigated. In I‐h experiments I pM tentoxin reduced K+ influx in the routs over the external K+ concentration range 0.1 to 1 mM (low‐K+ plants), whereas stimulation was observed al lower and higher K+ concentrations. On the other hand, in plants grown at 0.3 mM K+, tentoxin stimulated the translocation of K+ from roots to shoots in 5‐h experiments. Valinomycin affected K+ transport only al high K+‐status (slight stimulation). In low‐K+ plants 2,4‐dinitrophenol (DNP) caused drastic inhibition of K+ uptake, but in high‐K+ plants uptake was only slightly inhibited and translocation slightly stimulated, It is concluded that the opposite effects of tentoxin on K+ uptake and translocation agree1 with the directions of the H+‐ATPases pumping H+ towards the apoplast and located at the cortex plasmalemma and the xylem parenchyma plasma‐membrane, respectively. These effects should probably be attributed to the interaction between tentoxin and the K+‐carrier protein rather than to a direct influence of tentoxin on H+‐ATPase.
|Number of pages||7|
|Publication status||Published - jan. 1 1988|
ASJC Scopus subject areas
- Plant Science
- Cell Biology