DARIUSZ PAŃKA, DARIUSZ PIESIK, MAŁGORZATA JESKE, NATALIA MUSIAŁ, KATARZYNA KOCZWARA

Transcription

1 EMISSION OF VOLATILE ORGANIC COMPOUNDS BY PERENNIAL RYEGRASS/NEOTYPHODIUM LOLII ASSOCIATION AS A DEFENSE REACTION TOWARDS INFECTION BY FUSARIUM POAE AND RHIZOCTONIA SOLANI DARIUSZ PAŃKA, DARIUSZ PIESIK, MAŁGORZATA JESKE, NATALIA MUSIAŁ, KATARZYNA KOCZWARA Department of Entomology and Molecular Phytopathology, University of Technology and Life Sciences, 2 Kordeckiego St., Bydgoszcz, Poland

2 The team Dr. Małgorzata Jeske MSc Katarzyna Koczwara, PhD student MSc Natalia Musiał, PhD student

3 N. coenophialum/rhizoctonia zeae Antibiosis in vitro N. uncinatum/fusarium culmorum N. uncinatum/trichoderma harzianum N. uncinatum/rhizoctonia solani

4 E+ (left) and E- (right) plants of Tf4 - tall fescue genotype diseased by Rz55 - R. zeae izolate

5 y = x Pearson's correlation r =.94 r 2 = 88% 6 y = 47,36-1,599 x Pearson's correlation r = -,191 r 2 = 38% Disease Index % Fusarium poae Disease Index [%] Hyphae density [number per mm] Hyphae density [number per mm] Neotyphodium coenophialum vs Rhizoctonia zeae in tall fescue Neotyphodium lolii vs Fusarium poae in perennial ryegrass 6 y = 38,424 -,9246 x Pearson's correlation r = -,1689 r 2 = 26% Relationship between endophyte mycelium density and infection level of plants Rhizoctonia solani Disease Index [%] Pańka D., West C.P., Guerber C.A., Richardson M.D Susceptibility of tall fescue to Rhizoctonia zeae infection as affected by endophyte symbiosis. Annals of Applied Biology, In Press Hyphae density [number per mm] Neotyphodium lolii vs Rhizoctonia solani in perennial ryegrass

6 4, 3, 2, E+ E- 1,, T_ T_1 T_2 T_3 T_4 T_5 T_6 4, 3, 2, 1,, T_ T_1 T_2 T_3 T_4 T_5 T_6 Mean content [μg/g DM] of total phenolic compounds analyzed to 6 days after inoculation by Fusarium poae (bottom) and Rhizoctonia solani (top) in E+ and E- perennial ryegrass genotypes

7 Research objectives whether endophyte infected (E+) perennial ryegrass plants are more resistant to disease caused by Fusarium poae and Rhizoctonia solani than non-infected (E-) plants, whether the N. lolii presence in perennial ryegrass affects emission of VOCs by the plants, what is the extent and direction of changes in VOCs emission under infection of perennial ryegrass by F. poae and R. solani whether three perennial ryegrass genotypes differ in susceptibility to infection by pathogens and what are the differences between them in terms of VOCs induction

8 Materials and Methods Three endophyte infected (E+) and noninfected (E ) perennial ryegrass genotypes Nl22, Nl6 and NlA6 were artificially inoculated with F. poae and R. solani by foliar spray Ten days after inoculation the degree of plants infestation was evaluated based on a five-degree scale where o stood for a lack of infection symptoms and 4 o above 6% of the area with disease symptoms, heavy wilting Volatile organic compounds were collected before inoculation and 3, 6 and 12 days (Intervals) after inoculation from Nalophan bags which enclosed perennial ryegrass plants. Volatiles were analyzed by coupled gas chromatography-mass spectrometry (GC-MS)

9 Disease severity [DI in %] Results disease severity 6 Fusarium poae E+ E- 6 bc Rhizoctonia solani 5 4 b B b B 5 4 b B a B a C a A a A a B a C a A a A Nl22 Nl6 NlA6 Nl22 Nl6 NlA6 Perennial ryegrass genotypes Mean infestation level of E+ and E perennial ryegrass genotypes by Fusarium poae (left) and Rhizoctonia solani (right). Values (n=4) marked with different letters differ significantly at P <.5. Capital letters indicate differences between genotypes and lower case letters indicate differences between E+ and E plants.

10 Results disease severity E+ (left) and E- (right) plants of Nl6 perennial ryegrass genotype infected by Fusarium poae

11 Results The most abundantly emitted volatile organic compounds Green Leaf Volatiles - GLVs (Z)-3-hexenal (Z)-3-hexen-1-yl acetate Linalool (Z)-ocimene β-caryophyllene Terpenes (Z)-3-HAL (Z)-3-HAC LIN (Z)-OCI β-car Shikimic acid pathway derivatives Benzyl acetate Indole Methyl salicylate BAC IND MAT

12 Results analysis of variance Source of variation Emitted volatile organic compounds Z-3-HAL Z-3-HAC Z-OCI LIN BAC MAT IND β-car Fusarium poae Interval (I) *** *** *** *** *** *** *** *** Genotype (G) n.s. n.s. n.s. n.s. n.s. * n.s. * Endophyte (E) *** *** *** *** * *** *** *** I G n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. I E *** *** n.s. *** * *** n.s. *** G E n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. I G E n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. Rhizoctonia solani Interval (I) *** *** ** *** *** *** ** *** Genotype (G) * ** * n.s. * * ** n.s. Endophyte (E) *** *** ** *** ** *** *** *** I G *** n.s. n.s. n.s. *** ** *** n.s. I E *** *** n.s. *** n.s. *** ** *** G E n.s. n.s. n.s. *** n.s. n.s. ** n.s. I G E *** n.s. n.s. * n.s. n.s. n.s. n.s. * P<.5; ** P<.1; *** P<.1; n.s. - not significant

13 Emission of VOCs [ng h -1 ] Results effect of endophyte status (E+, E-) on the content of volatile organic compounds 16 b Fusarium poae 16 Rhizoctonia solani b a E+ E 8 a b 8 6 a 6 b 4 2 b a b b a b a b a a Z-3-HAL Z-3-HAC Z-OCI LIN BAC MAT IND β-car 4 2 b a a b b a b a b a b a b a a Z-3-HAL Z-3-HAC Z-OCI LIN BAC MAT IND β-car Volatile organic compounds (VOCs) Mean emission of volatile organic compounds by E+ and E perennial ryegrass genotypes infected by Fusarium poae (left) and Rhizoctonia solani (right)

14 Emission of VOCs [ng h -1 ] Results effect of endophyte status (E+, E-) and intervals (DAI) on the content of volatile organic compounds 3 Fusarium poae 3 Rhizoctonia solani Z-3-hexen-1-yl acetate Z-3-hexenal Linalool Methyl salicylate β-caryophyllene Z-Ocimene 1 1 Benzyl acetate Indole 5 5 E+ E E+ E E+ E E+ E E+ E E+ E E+ E E+ E DAI 3 DAI 6 DAI 12 DAI DAI 3 DAI 6 DAI 12 DAI Intervals - days after inoculation by pathogen (DAI) Mean emission of volatile organic compounds by E+ and E perennial ryegrass genotypes in the 3rd, 6th, 12th day after inoculation by Fusarium poae (left) and Rhizoctonia solani (right) and in control combination

15 Conclusions Neotyphodium lolii presence in perennial ryegrass genotypes significantly decreased level of infection by Fusarium poae and Rhizoctonia solani Endophyte infected and non-infected plants of the tested perennial ryegrass genotypes emitted most abundantly two green leaf volatiles (GLVs): (Z)-3- hexenal, (Z)-3-hexen-1-yl acetate, three terpenes: linalool, (Z)-ocimene, β- caryophyllene and three shikimic acid pathway derivatives: benzyl acetate, indole, and methyl salicylate Higher amounts of volatile organic compounds were emitted by perennial ryegrass genotypes diseased by Fusarium poae than Rhizoctonia solani Neotyphodium lolii presence increased the emission of volatile organic compounds in perennial ryegrass genotypes before and after inoculation by Fusarium poae and Rhizoctonia solani

16 Conclusions Perennial ryegrass genotype was the weakest factor affecting emission of VOCs. It significantly influenced the release of methyl salicylate and β- caryophyllene only when diseased by Fusarium poae and the most of VOCs ((Z)-3-hexenal, (Z)-3-hexen-1-yl acetate, (Z)-ocimene, benzyl acetate, indole, methyl salicylate) when diseased by Rhizoctonia solani Intervals of volatile organic compounds collections were a highly significant source of variation for all emitted volatiles. Most of the VOCs ((Z)-3-hexen- 1-yl acetate, (Z)-3-hexenal, linalool and methyl salicylate (only after F. poae infection)) reached their highest levels of emission on the sixth day after inoculation Pańka D., Piesik D., Jeske M., Baturo-Cieśniewska A Production of phenolics and the emission of volatile organic compound (VOCs) by perennial ryegrass (Lolium perenne L.)/Neotyphodium lolii association as a response to infection by Fusarium poae. Journal of Plant Physiology, 17:

17 Thank you for your attention