Production of ethylene by tissues of tomato, pepper, French-bean and cucumber in response to infection by Botrytis cinerea

277

Physiological and Molecular Plant Pathology (1990) 36, 277-287

Production of ethylene by tissues of tomato, pepper, French-bean and cucumber in response to infection by

Botrytis cinereaYIGAL ELAD Department of Plant Pathology, Agricultural Research Organization, The Volcani Center, Bet Dagan 50 250, Israel (Accepted for publication January 1990)

Ethylene production by detached leaves of tomato, pepper, bean and cucumber infected by Botrytis cinerea was much higher than that of noninfected leaves of the same hosts . Maximum production of ethylene was observed in leaves showing mild symptoms of the disease as compared with noninfected or completely infected leaves . The fungus produced negligible amounts of ethylene when grown on autoclaved leaves, with the exception of pepper leaves supplemented with methionine (0 . 14 nl g t h-4 ) . Exogenously supplied ethylene induced 75-370°,, more necrosis than B. cinerea infections in all the crops . Applications of methionine increased necrosis to a lesser extent. Silver-thiosulphate (STS) at levels of 10-4 and 10 -5 M, aminooxyacetic acid (AOA 10-s and 10-4 M) and aminoethoxyvinylglycine (AVG 10-s and 10-4 M) reduced the development of grey mould disease significantly . AOA and AVG inhibited the production of ethylene by all the crops . Disease incidence in cucumber fruits was increased by growth at 4 ° C or treatment with ethephon prior to inoculation whereas STS treatments completely inhibited disease development. Disease development was also decreased in intact plants treated with the inhibitors .

INTRODUCTION During normal plant growth the amount of ethylene produced is usually relatively low, but slight peaks in production occur mainly around germination, when the plant is mature, and during leaf abscission [9] . Abscission of diseased leaves is common in plants infected with fungi [4, 11] . It is known that stress factors such as chemical treatments, irradiation, drought, infestation with pests, diseases and mechanical injuries cause increases in ethylene production [3, 8, 16] . Boller et al . [1] proposed that ethylene-induced chitinase in bean leaves may function as a defence enzyme against fungal and bacterial invaders . However, Mauch et al . [10] suggested later that ethylene production is a symptom of, and not a signal for the induction of the enzyme in pea pods infected by Fusarium solani . Maintaining ethylene concentration in the storage atmosphere at < 0 . 01 µl 1 -1 increased the susceptibility of tomato fruits to infection by Botrytis cinerea Pers ., whereas higher concentrations resulted in less infection [7] . Ethylene in the storage atmosphere has been reported to stimulate postharvest decay by other fungi also [6] . Infection of wheat seedlings by tContribution from the Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel No . 2144-E, 1987 series . 0885--5765/90/040277+11

$03 .00/0

© 1990 Academic Press Limited



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Yigal Elad

Septoria nodorum was found to induce the formation of ethylene and chemical control of infections was associated with a reduction in ethylene production [15] . Botrytis cinerea is a major pathogen of vegetables grown in Israel and elsewhere, especially under plastic cover during the winter . Severe damage is inflicted by grey mould epidemics on cucumber [5], tomato, bean and pepper . The purpose of this work was to study the possible involvement of ethylene in the development of grey mould disease caused by B . cinerea on vegetable crops .

MATERIALS AND METHODS

Organisms and growth conditions Botrytis cinerea Pers . was isolated from naturally infected female flowers of cucumber [5] . The fungus was maintained on potato dextrose agar (PDA Difco) and then tested on the following host plants : bean (Phaseolus vulgaris L . cv . Brittle Wax or cv . Hilda), cucumber (Cucumis sativus L . cv . Delila), pepper (Capsicum annuum L . cv . Maor) and tomato (Lycopersicon esculentum Mill . cv . VF 198) . Plants or detached leaves were inoculated with B . cinerea using agar disks infested with mycelium or conidial suspensions as described below . A disk from the growing margin of a PDA culture of B . cinerea was placed in the middle of each leaf . The area of necrotic tissue developing in the leaves around the inoculum was measured after different periods of incubation . Controls with sterile PDA did not produce necrosis when incubated under the same conditions . A conidial suspension (1-3 x 10' spores ml - ') from 2-week-old cultures grown on PDA, supplemented with 0 . 1 M glucose, were sprayed on either leaves or on whole plants . The inoculated leaves were placed over water in a plastic box . The box was enclosed in a plastic polyethylene bag to maintain humid conditions during incubation . Inoculated plants were either incubated in a plastic bag or placed in a dew chamber . Plants and detached leaves were incubated in a growth chamber with 12 h photoperiod at 20±2 °C. Disease severity was recorded on a scale of 0-5, where 0 = healthy leaf and 5 = leaf completely destroyed .

Ethylene determination Five leaves (of 8-10 week old plants) were placed in a 32 ml glass test tube (25 mm diam . x 95 mm height) and the tube was closed with a rubber stopper . For whole plant measurements the aerial parts of 4-6-week-old plants were enclosed in plastic bags . Samples were incubated in the sealed containers for 2-5 h at 20 ° +2 °C . The ethylene present in gas samples removed from the containers was measured with a gas chromatograph (Gow-Mac Instrument Co ., Series 750) fitted with a flame ionization detector and a 3 ft glass column packed with allumina . The rate of ethylene production was expressed as nI g- ' fresh weight h - ', using pure ethylene as a standard . There was no detectable ethylene in empty glass test tubes but very low levels were measured in the atmosphere of empty plastic bags . B . cinerea was grown on PDA or on PDA supplemented with blended leaves of the various plants . Leaves of the various hosts were laced in 32 ml bottles plugged with cotton wool and autoclaved for 20 min at 121 °C before inoculating with B . cinerea . Lmethionine (Sigma Chemical Co ., U .S .A.) was added to autoclaved leaves before inoculation . On the eighth day the cotton wool plug was replaced with a rubber stopper and the ethylene present was measured a day later .



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Treatments with chemical substances Ethylene mixed with air was injected into a closed vessel (final concentration of ethylene 12 nl 1 - ') in which infected leaves were placed . The system was aerated every day, resealed, and supplied with a fresh ethylene mixture . Solutions of L-methionine, (Sigma) aminooxyacetic acid (AOA, Sigma), aminoethoxyvinylglycine (AVG, Sigma) and silver thiosulfate (STS-prepared from silver nitrate and sodium thiosulfate, 1 : 8 mol/mol) were sprayed on leaves or plants immediately before inoculation with B . cinerea . Fungicidal control was achieved with the fungicide isopropyl N-(3,4diethoxyphenyl) carbamate (diethofencarb) plus carbendazim 50 % wp (Supplied by Agan Ltd ., Israel) at a concentration of 0 . 2 °o . Experiments with female flowers of cucumber Female flowers of a parthenocarpic cucumber cv . Kasem 292 were harvested from a commercial greenhouse in April 1987, one month after the final application of the fungicides . Some of the flowers were held at 4 ° C for 12 h in a refrigerator . STS (5 mm), ethephon (20 ppm) and Botrytis conidia (l0' ml - ') supplemented with 0 . 1 M glucose were sprayed on the open flowers 24 h after picking . Flowers were kept in 32 ml glass bottles at 100 11,/ humidity . Ethylene production was tested 3, 5 and 7 days after the flowers were picked . Experimental design All experiments included five or six replicates of each treatment . The experiments were repeated at least three times and the results presented are from representative experiments . RESULTS

Ethylene production by infected tissues Measurements of ethylene production by leaves of cucumber and bean showing different levels of infection showed that maximum levels were emitted by leaves showing a low disease index (Fig . 1) . Ethylene production decreased with increase in disease severity and leaves which were completely necrotic (disease index-5) produced small amounts of ethylene only or none at all . The pattern of ethylene production by healthy and wounded leaves of pepper, tomato and bean was compared with that by diseased leaves showing mild to severe necrosis (Fig. 2) . Very low production was observed in both healthy and wounded leaves during 7 days of incubation . Slow spreading necroses were associated with a gradual increase in ethylene production, up to 5 . 2 nl h - ' g- ' fresh w t . i n pepper, 30. 0 nl h-' 9-' in tomato and 11 . 7 nl h - ' g - ' in bean . Fast spreading necroses gave peaks of production around the fourth to sixth day after inoculation in pepper, the third day in tomato and the fourth day in bean . Healthy leaves of tomato, bean and cucumber produced 0 . 06, 0 and 0.06 nl g - ' h - ' ethylene, respectively . Production of ethylene by wounded leaves of tomato was 0 . 70 nl g - ' h- ', of bean was 0.49 nl g -1 h - ' and of cucumber was 0 . 09 nl g - ' h- ' . Infected leaves produced 34 (tomato), 54 (bean) and 52 (cucumber), times the amount of ethylene produced by wounded leaves . Production by B . cinerea after 9 days growth on autoclaved leaves of cucumber was



280

Yigal Elad

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I I I

1

2

3

0

1

DISEASE INDEX FIG . 1 . Ethylene production by Botrytis cinerea infected leaves of bean cv . Brittle Wax (a) primary leaf, (b) secondary leaf ; cucumber true leaves (c) 4 days after inoculation . (Bar = ±SE) .

0 . 04 nl g - ' h -1 on bean 0 and on pepper 0.06 nl h-1 g -1 . The amount of ethylene produced on autoclaved leaves supplemented with 1 mm methionine was 0 . 05 nl g - ' h"' on cucumber, 0 bean and 0 . 14 nl h - ' g-1 pepper . The level of production by leaves supplemented with methionine was not statistically significant from that of unsupplemented leaves . The fungus grew well on both supplemented and unsupplemented media . B . cinerea did not produce detectable amounts of ethylene when grown on PDA or PDA supplemented with blended leaves of pepper, bean, tomato or cucumber . Influence of exogenous ethylene, methionine, STS, AOA and AVG on the development of

B . cinerea infections in leaf tissue Leaves of the different species were inoculated with mycelium of B . cinerea and incubated in closed vessels in an atmosphere containing ethylene at a concentration of 12 nl 1 - ' (Fig . 3) . The exogenously supplied ethylene increased the size of the necrotic areas produced 5 days after inoculation in pepper by 87 %, in tomato by 90 % and in bean by 77 % . True leaves and cotyledons of cucumber were also inoculated with conidia of the pathogen . The disease index in untreated cucumber leaves was 1 . 0 after 9 days but in ethylene-treated leaves it was 3 . 6 after the same period . On the other hand ethylene did not increase necrosis severity in cotyledons of cucumber . The application ofmethionine at concentrations of 5 or 50 mm increased disease development



Production of ethylene by tissues in infection by Botrytis

cinerea

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6 5 3 4 3

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DAYS OF INCUBATION FIG . 2 . The relationship between the amount of necrotic tissue (right) and production of ethylene (left) by leaves of (a) pepper, (b) tomato and (c) bean cv . Brittle Wax . The leaves were inoculated with an agar block infested with Botrytis cinerea . Ethylene production by leaves in which necrosis developed slowly (V) was measured separately from those in which necrosis developed rapidly (A) . (Q) uninfected control (0) leaves wounded by scratching with a needle . (Bar= f SE) .



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4 5 2 3 DAYS AFTER INOCULATION

3

4

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FIG . 3 . The effect of exogenously supplied ethylene at a concentration of 12 nll - ' on the development of disease in detached leaves of (a) pepper, (b) tomato, and (c) bean cv . Brittle Wax . Leaves were inoculated with blocks of agar infested with mycelium (a-c) (Q), control . (e), infected (Bar= ±SE) .

15

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DAYS AFTER INOCULATION

Development mycelium. (a) tomato, were treated with silver inoculation . Untreated FIC . 4 .

of necrosis in leaves inoculated with a block of agar infested with (b) bean cv . Brittle Wax, (c) pepper, (d) bean cv . Hilda. Detached leaves thiosulfate at concentrations of 10 -e M (A) and 10-4 M (p) at the time of control (Q) . (Bar= ±SE) .



Production of ethylene by tissues in infection by Botrytis cinerea 283 in leaves and cotyledons of cucumber and in leaves of cucumber, pepper and the two cultivars of bean, but not in tomato leaves . Ethylene did not affect conidial germination and hyphal growth of B . cinerea on PDA . Silver thiosulfate was sprayed at concentrations of 10 -4 and 10-s M onto leaves of tomato, bean and pepper prior to inoculation with conidia . Disease severity in untreated controls reached indices of 3 . 7 (tomato), 4 . 2 (bean) and 4.6 (pepper) 8 days after inoculation . Disease severity was reduced by the treatments by 100-23 % 4-8 days after inoculation of the leaves . Silver thiosulfate also significantly reduced disease development in tomato, bean and pepper leaves inoculated with mycelium (Fig . 4) . AOA, sprayed at concentrations of 10 -3 and 10 -4 M prior to inoculation of leaves, reduced the necrotic area produced in cucumber, tomato and pepper but not in bean cv . Brittle Wax, relative to untreated leaves . Ethylene production by the inoculated leaves was significantly (P = 0 . 05) reduced except in those of bean up to 8 days after inoculation (Fig . 5) . AVG at a concentration of 5 x 10 -4 M inhibited disease development in bean leaves 8 days after inoculation by 61-76 "ô while 5 x 10 -3 M AVG prevented it completely . Disease development in tomato was inhibited by 5 x 10 -4 M AVG only by 26-50 % and it was completely prevented by 5 x 10 -3 M AVG (Table 1) . Ethylene production was drastically reduced in both tomato and bean leaves by treatments with AVG at a concentration of 5-10 - 'm but treatment with 5-10 - 'm was effective in reducing ethylene production only up to 7 days of incubation . Exogenous ethylene added to the atmosphere surrounding leaves of tomato and bean, previously treated with AVG and AOA, overcame the inhibitory effects of these compounds on disease development . Intact bean plants were treated with methionine, inhibitors of ethylene production or of ethylene action, or with the fungicidal mixture diethofencarb+carbendazim (Fig . 6) . Methionine treatment increased disease severity by 130%, 3 days after infèction, but this effect declined later . AVG reduced disease development by 28-67 °o, AOA and STS by 80-33().,, while treatments with diethofencarb+carbendazim prevented it completely (Fig . 6) . Ethylene production (in nl h -i g-1 ) by the bean plants was, for nontreated (2 . 4) or treated with AOA (0), AVG (0), STS (2 . 8), methionine (3 . 7) and glucose (2 . 1), 13 days after treatment . All treatments except glucose significantly increased or reduced production over the control (P = 0.05) . B . cinerea was grown on PDA supplemented with 10 -s -10-4 M AOA, AVG, STS or methionine . Linear growth of the fungus was not affected by any of the compounds . Conidia of B . cinerea were inoculated on the same media but no effects on conidial germination were observed .

Influence of predisposition by cold temperature treatment or treatments with ethephon and STS on the response offemale flowers of cucumber to Botrytis cinerea Female flowers of cucumber were incubated at 20 ° C for 7 days (Table 2) . Ethylene production was highest after 5 days of incubation . Predisposing the flowers at 4 °C caused 20-37 % increase in ethylene production . A less pronounced effect was observed with silverthiosulfate (5 mm) . Inoculation of flowers caused a significant increase in ethylene production (Table 2) . The incidence of grey mould 7 days after inoculation

2 84

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DAYS AFTER INOCULATION

Ftc . 5 . Development of necrosis (---( and production of ethylene treatment with aminooxyacetic acid (a) Cucumber, true leaves (b) tomato leaves (d) bean leaves cv . Brittle Wax (e) pepper leaves . AOA after inoculation with mycelium, at rates of (V), 10-9 M and (Q) (Bar= ±SD) .

( ) in leaf tissues after cucumber cotyledons (c) was sprayed immediately 10 -s M . (O), not treated

was 57% . Ethephon (25 ppm) and the cold treatment increased disease incidence by up to 100 %, whereas all of the STS-treated flowers remained healthy (Table 1) .

DISCUSSION Many workers have reported increased ethylene production by diseased plants [6-8, 10-12, 14, 15] . The production of ethylene by diseased plants was recently reviewed by Goodman et al . [8] . Studies with a number of plant species suggest that increased ethylene synthesis and tissue senescence are responses to stress [2] . Ethylene production by the crop species studied in this work was significantly higher



285

Production of ethylene by tissues in infection by Botrytis cinerea TABLE 1

The effect of aminoethoxyvinylglycine on disease development and ethylene production in bean and tomato leaves infected with Botrytis cinerea

AVG concentration Crop Bean Bean Bean Tomato Tomato Tomato

(M)

0 5 . 10-9 5 . 10 -3 0 5 . 10 -4 5 . 10-s

Necrotic area (cm 5 l

Ethylene production (til h -i g``

5 7 8 Days after inoculation

5 7 8 Days after inoculation

0 .8a 0 .3a Oa 1-la 0 .5b Oc

4-8a 1 . 76 Ob 2-8a 0. 96 Oc

9-6a 2-3a Ob 12-3a 8-66 Oc

11-la 2-3b Ob 8. 3a 01) Ob

12. 3a 6. 7b 0. 3e 9-la O-8b Ob

15 . 8a 14-la 0 . 9b 7-2a 6-3a 0 . 2b

Leaves of bean or tomato were inoculated by applying an agar block infested with mycelium and then sprayed with aminoethoxyvinylglycine (AVG) . Values in each column for each crop followed by a common letter are significantly different according to Duncan's Multiple Range Test (P < 0. 05) .

4 x

W Z w

2 ô

0 3

5

7

9

11

13

DAYS AFTER INOCULATION

FIG . 6 . Control of grey mould of bean (cv . Brittle Wax) . The aerial parts of the plants were inoculated by spraying with a conidial suspension of Botrytis cinerea and then either sprayed with 5. 10` M methionine (O) 10-3 M AOA (A), 10-3 M AVG (D), 10 - 'm STS (V) or a mixture of diethofencarb plus carbendazim (500+500 gg ml -t ) (e) . Untreated controls (O) . (Bar +SE) .

from tissues infected by B. cinerea than from wounded tissues . Ethylene was produced by the healthy cells surrounding the degenerating tissue . B . cinerea grown on various nutrient sources did not produce ethylene . The application of ethylene or of its precursor methionine to inoculated tissues accelerated disease development . Conidial germination and mycelial growth of B. cinerea was not affected by methionine at the concentrations used and it is concluded that the ethylene is produced mostly by the plant tissue with its production being triggered by the infecting pathogen . However, the mechanism which triggers production is unknown . The increases in ethylene production paralleled initial disease development and was at its maximum when moderate symptoms were observed .



Yigal Elad

286 TABLE 2

Effect of inoculation with B . cinerea, predisposing to 4 °C and treatments with stlcerthrosnlfale (Si S) and ethephon on ethylene production and incidence of grey mould offèmale flowers of racism her Ethylene production (In] Il - 'i

Temp . ( °C) of incubation prior to treatment Treatment 20 4 20 20

STS° Ethephon°

Incidence of grey mould a"

Non-inoculated

Inoculated"

Inoculated"

Days of incubation 5

Days of incubation 5

Days of incubation 3 5 7

3 3. 45a 4. 73b 4. 52b

13 . 38a 16. 41b 15 . 4lb

7

3

Oa Oa 7 . 22b

5 . 34a 6 . 45b 7 . 22b

44 . O1a 52 . 81b 47 . 36ab

7 3 . 86a 4 . 72b 4 . 58ab

Oa 4a Oa 9b

33ab 63b Oa 66b

57b 71b Oa 82b

Female flowers of cucumber were picked in a greenhouse and incubated in the laboratory with their basal side dipped in water in 32 ml glass bottles at 100% RH . The flowers were incubated at 4 °C or 20 °C for 12 h prior to incubation at 20 °C . ° Flowers were sprayed with either 5 mm silverthioselfate (STS) or ethephon (20 ppm) . 'Flowers were inoculated by spraying 103 ml - ' conidia of B . cinerea supplemented with 0 . 1 m glucose . Flowers were then incubated in 100 °~ RH . Treatments in each column followed by a common letter are not significantly different from each other according to Duncan's Multiple Range Test (P < 0 .05) . Production of ethylene by inoculated flowers was significantly (P = 0. 05) higher than production of ethylene by untreated flowers at all dates and treatments .

The application of AOA and AVG, known inhibitors of ethylene production decreased both disease development and ethylene production . The application of silver thiosulfate also reduced disease development . Although AVG is an inhibitor of ethylene production it may also inhibit protein synthesis . Furthermore AOA inhibits ACC synthase, an enzyme involved in ethylene production but it also inhibits transaminases such as phenylalanine ammonia lyase (PAL) and so could interfere with the development of the necrotic reaction . The pathogen itself was not influenced by STS, AOA and AVG in concentrations at which the substances were applied to and shown to be effective in disease reduction in the hosts . Disease in stored vegetable crops was correlated with the presence of ethylene in the air around the crop [7, 12] . Therefore, Reyes & Smith [12] recommended the removal of ethylene from the atmosphere of stored products . Ethylene regulates leaf senescence and is detected in parasitized tissue . It was suggested that several hydrolytic enzymes are present at higher levels along with ethylene [8] . Our work indicates that ethylene increases the severity of the disease developed in response to infection by Botrytis in all the crops tested and that inhibition of ethylene biosynthesis or action in the tissues has the opposite affect . [1, 4, 13],

The author wishes to thank Ms Hanne Volpin, Ms Gilly Shimshoni, Mr H . Yunis, Mr N . Ayash and Mr O . Kleifeld for their help and advice and Drs Susan Luria and Ruth Ben-Arie for their help with the gas chromatograph . The research was partly supported



Production of ethylene by tissues in infection by Botrytis cinerea

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by grants from the Funds for Priority Projects and the Council of Vegetable Growers and by the National Council for Research and Development .

REFERENCES

(1986) . Ethylene production in pepper (Capiscum annuuin Xanthomonas campestris pv . vesicatoria . Physiological and Alolecular Plant Pathology 29,

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leaves infected with 305--316 .

U . (1983) . Chitinase in bean leaves : induction by ethylene, purification, properties, and possible function . Planta 157, 27-31 . 3 . BRADFORD, K . J . & YANG, S . F . (1980) . Stress induced ethylene production in the ethylene-requiring tomato diagotropica . Plant Physiology 65, 327-330 . 4 . COHEN, R ., Riov, J ., LISKER, N . & KATAN, J . (1986) . Involvement of ethylene in herbicide-induced resistance to Fusarium oxysporum f. sp. melonis . Phytopathology 78, 1281-1285 . 5 . ELAD, Y . (1987) . Ultrastructural scanning electron microscopical study of parasitism of Botrytis cinerea on flowers and fruit of cucumber . Transactions of the British Mycological Society 91, 185-190 . 6 . EL-KAZZAZ, M . K ., SAMMER, N . F . & KADER, A. A . (1983) . Ethylene effect on in vitro and in vivo growth of certain postharvest fruit infecting fungi . Phytopathology 73, 998--1001 . 7 . GEESON, J . D ., BROWNE, K . M . & GUARALDI, F . (1986) . The effect of ethylene concentration in controlled atmosphere storage of tomatoes . Annals of Applied Biology 108, 605-610 . 8 . GOODMAN, R . N ., KIRALY, Z . & WOOD, K . R . (1986) . The Biochemistry and Physiology of Plant Disease . University of Missouri Press, Columbia . 9 . LIEBERMAN, M . (1979) . Biosynthesis and action of ethylene . Annual Review of Plant Physiology 30, 533-591 . 10 . MAUGH, F ., HADWIGER, L . A . & BOLLER, T. (1984) . Ethylene : symptom, not signal for the induction of chitinase and ß 1,3-glucanase in pea pods by pathogens and elicitors . Plant Physiology 76, 607-611 . 11 . REUVENI, R ., PERL, M . & ROTEM, J . (1976) . Inhibition of shedding of pepper leaves infected with powdery mildew (Leveillula taurica) by application of auxins . Phytoparasitica 4, 197-199 . 12 . REYES, R . A . & SMITH, R . B . (1986) . Controlled atmosphere effects on the pathogenicity of fungi on celery and on the growth of Botrytis cinerea . Horticultural Science 21, 1162-1167 . 13 . Riov, J . & YANG, S . F . (1982) . Effects of exogenous ethylene on ethylene production in citrus leaf tissue . Plant Physiology 70, 136-141 . 14. WIESE, M . V . & DEVAY, J . E . 1970) . Growth regulator changes in cotton associated with defoliation caused by Verticillium albo-atrum . Plant Physiology 45, 304-309 . 15 . WURZER-FASSNACHT, U . & HOFFMANN, G . M . (1986) . Ethylene formation of wheat germlings infected by Seploria nodorum and the effect of .seed dressing . Zeitschrift fur Pflanzenkrankheiten und Pflanzenschutz 93, 347--355 . 16 . Yu, Y . B . & YANG, S . F. (19801 . Biosynthesis of wound ethylene . Plant Physiology 66, 281-285 . 2 . BOLLER, T ., GEHRi, A ., MAUCH, F . & VOGEL!,