Rapidly Induced Wound Ethylene from Excised Segments of Etiolated Pisum sativum L., cv. Alaska

Abstract

Wound-induced ethylene synthesis by subapical stem sections of etiolated Pisum saivum L., cv. Alaska seedlngs, as described by Saltveit and Dilley (Plant Physiol 1978 61: 447450), was half-saturated at 3.6% (v/v) 02 and saturated at about 10% 02. Corresponding values for CO2 production during the same period were 1.1% and 10% 02, respectively. Anaerobiosis stopped all ethylene evolution and delayed the characteristic pattern of wound ethylene synthesis. Exposing tissue to 3.5% CO2 in air in a flowthrough system reduced wound ethylene synthesis by 30%. Enhancing gas diffusivity by reducing the total pressure to 130 mm Hg almost doubled the rate of wound ethylene synthesis and this effect was negated by exposure to 250 #1 liter-1 propylene. Applied ethylene or propylene stopped wound ethylene synthesis during the period of application, but unlike N2, no lag period was observed upon flushing with air. It is concluded that the characteristic pattern of wound-induced ethylene synthesis resulted from negative feedback control by endogenous ethylene.No wound ethylene was produced for 2 hours after excision at 10 or 38 C. Low temperatures prolonged the lag period, but did not prevent induction of the wound response, since tissue held for 2 hours at 10 C produced wound ethylene immediately when warmed to 30 C. In contrast, temperatures above 36 C prevented induction of wound ethylene synthesis, since tissue cooled to 30 C after 1 hour at 40 C required 2 hours before ethylene production returned to normal levels. The activation energy between 15 and 36 C was 12.1 mole kilocalories degree-'.A rapidly induced, transitory increase in the rate of ethylene synthesis has been observed in a variety of excised tissues (1,24). The wound response was recently characterized in Pisum sativum L., cv. Alaska (24). In subapical stem tissue wound-induced ethylene production at 25 C increased linearly after a lag period of 26 min from 2.7 nl g-' hr-' to the first maximum of 11.3 nl g-' hr-' at 56 min. The rate of production then decreased to a minimum at 90 min, increased to a lower second maximum at 131 min, and then declined over a period of about 100 min to about 4 nl g-' hr-'. The magnitude of the response varied slightly from experiment to experiment, but the time sequence was constant for tissue excised from a given region of the pea seedling. In this study we examined the 02 and temperature dependency of woundinduced ethylene synthesis by etiolated 'Alaska' pea stem sections.Vegetative, ripening, and senescent tissue require 02 for ethylene synthesis (1,3, 6,13,21,29

Autoinhibition of Ethylene Production in Citrus Peel Discs

“…Autoinhibition of ethylene production has been described in various plant tissues (12,14,15,20,21). The present study shows that it also occurs in peel tissues of citrus fruit.…”

“…Autoinhibition of ethylene production in grapefruit flavedo discs occurs at about the same concentration range (Fig. 4) reported for other tissues (14,15,20,21).…”

“…Several reports, however, have demonstrated autoinhibition of ethylene production (12,14,15,20,21). Vendrell and McGlasson (15) were the first to report that ethylene treatment significantly inhibited wound ethylene production of banana pulp slices.…”

Stress-induced Ethylene Production in the Ethylene-requiring Tomato Mutant Diageotropica

“…Kawase (7) also reported a stimulation of ethylene production by anaerobic stress in sunflower stems. Saltveit and Dilley (9) showed that an anaerobic stress would induce 1.16* * Difference from control significant at P < 0.05; *** difference from control significant at P < 0.001. a rise in ethylene production similar to that which followed physical wounding of pea epicotyls. Both wounding and anaerobiosis increase ethylene synthesis in excised tomato roots (6).…”

Ethylene Biosynthesis and Accumulation under Drained and Submerged Conditions (A Comparative Study of Two Rumex Species)

“…In this way a higher ACC level may partly relieve the reduction of the specific activity of ACC oxidase brought about by oxygen shortage. As a result of the opposing effects of submergence on ACC synthase and ACC oxidase, hypoxia leads to a net inhibition of ethylene production in most plant species that have been studied (Saltveit and Dilley, 1978;Konze et al, 1980;Raskin and Kende, 1983;Pearce et al, 1992) and a net stimulation of ethylene production in maize roots (Jackson et al, 1985;Atwell et al, 1988;Brailsford et al, 1993) and rice internodes (Raskin and Kende, 1984). In both Rumex species, the balance between an increased availability of ACC synthase and a reduction of the specific activity of ACC oxidase may determine the net negative effect of submergence on the ethylene production rate.…”