HIGH-TEMPERATURE ENHANCES ETHYLENE PROMOTION OF ANTHER FILAMENT GROWTH IN BRUSSELS-SPROUTS (BRASSICA-OLERACEA VAR GEMMIFERA)

A study was made of the effect of high temperature on the growth response of Brussels sprout filaments to ethylene. Filaments with or without the anthers attached were incubated continuously at 25-degrees-C or 35-degrees-C for 7 days or for 2 days at 35-degrees-C followed by 5 days at 25-degrees-C. Growth was reduced during both 35-degrees-C treatments compared to that of filaments at continuous 25-degrees-C. Ethylene had little effect on filament growth at continuous 25-degrees-C, whereas with treatment for either 2 or 7 days at 35-degrees-C ethylene promoted filament growth considerably. Thus ethylene effectively overcame the growth inhibition induced by the 35-degrees-C treatment. High temperature treatments reduced ethylene production from filaments alone, and from filaments with anthers attached. The ethylene biosynthesis inhibitor aminoethoxyvinylglycine (AVG) and the ethylene action inhibitor AgNO3 enhanced filament growth at 25-degrees-C but had little or no effect at 35-degrees-C. The relevance of temperature to ethylene sensitivity is discussed in relation to filament growth and to other plant processes in general.