Antioxidant responses during fusarium infection: the sampling and the first results

Gallé Ágnes

Fusarium head blight (FHB) is an important disease of wheat and has worldwide distribution, which results in yield loss and mycotoxin contamination of grain when the disease is caused by a mycotoxin-producing Fusarium species.

Fusarium graminearum and F. culmorum are the Fusarium species that most commonly cause FHB of wheat and both can produce trichothecene mycotoxins, predominantly deoxynivalenol (DON, also known as vomitoxin) (Parry et al. 1995).

The fungus produces trichothecene mycotoxins, such as deoxynivalenol (DON).

Effect: • livestock feed refusal• depression of the immune system• nausea and vomiting in humans (Hall and Van Sanford, 2003)

Resistance to FHB is very complex and is considered to be quantitatively governed by numerous resistance

genes located on different chromosomes.

At least 18 of the 21 wheat chromosomes have been reported to be associated with resistance.

The components of the defense reactions have been extensively investigated with both protein and

transcript profiling.

Some gene families which were induced during Fusarium infection (microarray): Saber et al 2007

wheat spikelets infected with F. graminearum

Some gene families which were induced during Fusarium infection (differential display RT-PCR):Ansari et al 2007

• Proteins with an antioxidant function: superoxide dismutase, dehydroascorbate reductase, and glutathione S-transferases (GSTs)

• A 14-3-3 protein homolog was also upregulated

• PR-2 protein (β-1, 3 glucanase) was upregulated in FHB-infected spikes

Expression of proteins with highest similarity to dehydroascorbate reductase and TaGSTF5 (a glutathione S-transferase) differed following FHB infection

in susceptible and resistant cultivars.

wheat spikelets infected with F. graminearum

Some protein families (examples) which were induced during Fusarium infection (2-dimensional displays of proteins): Zhou et al 2005

SOD, KAT, GR, POD and GST activity determination

GK Mini Manó/Nobeokabozu genetic mapping population

(Prof. Mesterházy Ákos )

Nobeokabozu: FHB resistant lineA recombinant line from China: ‘WSY’, Wangshubai/Sumai3/Yangangfanzhou

GK Mini ManóArthur 71 / Sava // Rusalka / NS 171.2 /3/ F 30.74Resistant line to e.g. leaf rust

Plant material

Gathering wheat ears and flag leaves 17. 06. 2010. Kecskéstelep,

Cereal Research Nonprofit Kht.GK Mini Manó/Nobeokabozu wheat population

(Prof. Mesterházy Ákos )

SOD activity

0

2

4

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20

↓Mn resistent ↑ Mn resistent ↓ Mn sensitive ↑ Mn sensitive

SO

D a

ctiv

ity (

U m

g-1

tota

l pro

tein

)

KAT activity

05

10152025303540

↓Mn resistent ↑ Mn resistent ↓ Mn sensitive ↑ Mn sensitive

KA

T a

ctiv

ity (

U m

g-1

tota

l pr

otei

n)

GR activity

0100

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400500

600700

800900

1000

↓Mn resistent ↑ Mn resistent ↓ Mn sensitive ↑ Mn sensitive

GR

act

ivity

(U

mg

-1 to

tal p

rote

in)

POD activity

0,000

2,000

4,000

6,000

8,000

10,000

12,000

↓Mn resistent ↑ Mn resistent ↓ Mn sensitive ↑ Mn sensitivePO

D a

ctiv

ity (

U m

g-1

tota

l pro

tein

)

Guaiacol peroxidase activity (Class III peroxidase)

Thank you for your attention!