at. tsurushima, bh. nakayashiki, by. tosa and bs. …...an oxidized derivative of linoleic acid...
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An Oxidized Derivative of Linoleic Acid (Mag-Toxin)Produced in Pyricularia oryzae
AT. Tsurushima, BH. Nakayashiki, BY. Tosa and BS. Mayama
AHannan University, Faculty of Business, Osaka, 580-8502, Japan.BKobe University, Faculty of Agriculture, Hyogo, 657-8501, Japan.
Active factors might relate directly or indirectly in pathogenicity of blast fungi .
Example (1)factors related with disease symptom(2)determinant of specific
pathogenicity
1. Pyrichalasin H production and pathogenicity of Digitaria-specific isolates
Mol. Plant Pathol. 6 (2005)
Mol. Plant pathol. 6 (2005)
Numbers of Production of Pathogenisity isoloates Host plant Pyrichalasin H on Digitaria
rice, Itallian ryegrass, foxtail millet, common millet, green bristle grass, finger millet, wheat, Lehman
32 livegrass, Jungle rice, rice cutgrass, buffelgrass, 0 0bamboo grass, etc
32 Digitaria sanguinalis (crabgrass) 31 311 Digitaria sumutsii (pangolagrass) 1 17 Digitaria holizontalis 6 6
Total 72 38 38
Summary (pyrichalasin H production and pathogenicity on Digitaria of Pyricularia isolates)
Result 1
1. There is a correlation between pyrichalasin H production and pathogenicityon Digitaria.
2. Pyrichalasin H was detected in spore germination fluid of a Digitaria isolate.3. Pretreatment of leaf sheaths of crabgrass with 3 g/ml pyrichalasin H led to the
penetration and colonization by nonhost isolate.
↓Production of pyrichalasin H might be responsible for the genus-specific pathogenicity of Digitaria isolates.
Kato et al (2001) Couch and Kohn (2002)pathogenicitymating the sequences of DNA restriction fragment three genes
length polymorphisms
P. oryzae is a new fungal species distinct from P. grisea.
This phylogenic difference between Digitaria isolates and the crop isolates could be related to the production of pyrichalasin H.
Kato et al., J. Gen. Plant Pathol. 66. 30 (2001)Couch, B. C. and Kohn, L. M., Mycologia 94. 683 (2002)
2. Necrosis-inducing Factor and Chlorosis-inducing Factor
CH3
CHO
OH
CH3
OHCHO
OH
OHOH
OH
CH3
CHO
OH
OH
OH
CH3
CHO
OH
OH
CH3
OH
O
OH
OHO
O
OH
Pyriculol Epipyriculol
Pyriculariol Pyricuol
3-(1',3'-pentadienyl)-3,4-dihydro-1H-2-benzopyran-4,8-diol
4-(1'-hydroxy-2'-butenyl9-1,4-dihydro-2,3-benzodioxocin-10-ol
Necrosis-inducing factors from P. grisea
NH
HO CH3
O
OH3C H
CH3
Tenuazonic acid
Pyrichalasin H
H 3CO
OH
NH
CH
H 3C OH
H
O OAc
H 3C
の
This is also produced inthe genera Cochliobolus and Alternaria
These were only reported by Pyricularia grisea
ーーーーーーーーーーーーーーーーーーーーーーーーー
ーー_
の4-(1’-hydroxy-2’-butenyl)-1,4dihydro-2,3-benzodioxocin-10-ol
d ip p ed in aceto n e fo r 24 h
fi lter ed th ro u gh fil te r p ap er(TO Y O, No . 2 )evapo ra ted
E tO A c-fr W a te r-fr
co ncen tr ated in vacu o
d isso lved in CH C l3
C HC l3 1% M eO H
3% M eO H
5% M eO H
10% M eO H
100% M eOH
21 3 4 5 6 7 8 9 10 11 12
A v e na iso la te
cu ltu red in o at m eal m edia for 10 d ays
ir rad ia ted w ith BL B l ig h t for 3 d ays
C ultu reS po re
Ger m in ation flu id
extracted with E tOA c ( tw ice )
N ecrosisC h lorosis
Advances in Genetics. Genomics and Control of Rice Blast Disease (2009)
Fig. 6. HPLC profile of Fr.6
Time (min)0 5 10 15 20
Ref
rect
ive
inde
x
Shim-pack PREP-ODS(H)Kit (4.6 mmI.D.X250 mmL), 60% MeOH , 0.8 ml/min. Detector:RI
Yellow peak fractions were toxic to oat leaves.
(1)
(2)
CH3
CHO
OH
OH
OH
CH3
OHCHO
OH
OH
(1) Pyriculol (2) Epipyriculol
Result 1
All isolates of Pyricularia (rice, weat, oat, finger millet, foxtail millet and common millet and crabgrass) produced pyriculol and epipyriculo as mainly necrosis-inducing principles
HPLC profile of Fr.7
Solvent: 65% acetonitrile; Flow rate: 1.4ml/minColumn: Shim-pack PREP-ODS(H)Kit
(4.6mm I.D. x 250mm)
Chlorosis induction (m/z 293)
Biosci. Biotechnol. Biochem. 74 (2010)
m/z 295
m/z 295
Biosci. Biotechnol. Biochem. 74 (2010)
Chemical structures of linoleic acid (1) , 8-oxo-octadeca-9E,12Z-dienoic acid (2)and 14-oxo-octadeca-9E,12Z-dienoic acid (3)
Biosci. Biotechnol. Biochem. 74 (2010)
(Reference)Mycelium of Pyricularia grisea biosynthesized 8-hydroxylinoleic acid from linoleic acid (Crista, Osboun and Oliw, 2003)
Biosci. Biotechnol. Biochem. 74 (2010)
Biosci. Biotechnol. Biochem. 74 (2010)
ROS generation in organelle of the cell of leaf segment treated with Mag-toxin I
Biosci. Biotechnol. Biochem. 74 (2010)
Effect of light on ROS generation and induction of cell death in the leaf segment treated with Mag-toxin Biosci. Biotechnol. Biochem. 74 (2010)
Result21. Chlorosis-inducing factor was an oxidized C18 unsaturated
fatty acid named Mag-toxin.2. Chlorosis was light-dependently induced on segments by
Mag-toxin.3. ROS generation was observed at mitochondria of cell after
30 min of the toxin treatment.4. Cell death was induced on cells of segments after 2h of the
toxin treatment5. ROS generation and cell death were light-independently
induced by the toxin. -