buckwheat

Ribonuclease activity of
uninfected and infected
buckwheat plants of
different varieties
Yana R. Sindarovska - O.I. Lozova - L.V. Yuzvenko - L.F. Didenko -
N.Ya. Spivak
Institute of Cell Biology and Genetic Engineering, NASU and
D.K. Zabolotny Institute of Microbiology and Virology, NASU

The areas of Fagopyrum
esculentum (buckwheat)
plants utilization
• Honey plant
• Boiled grains –
traditional dish in
some countries
• Medical use: leaves
are antioxidants;
leaves and flowers
can alleviate some
specific diseases

The diseases of
buckwheat plants
• About 30 different pathogenic
organisms affect buckwheat plants:
• fungi (Реronоsроrа – mildew, Fusarium,
Phytophthora, Erysiphe –powdery mildew),
• bacteria (Pseudomonas syringae –
bacteriosis)
• and viruses (tobacco mosaic virus,
buckwheat burn virus).
)

Buckwheat burn virus
• Buckwheat burn virus has
negative-sense ss RNA
genome and can be included
into Rhabdoviridae id family.
• The virus is a high virulent
pathogen for buckwheat,
potato, tomato, tobacco,
pea, cucumber etc.
• The virus can decrease
buckwheat yields for up to
80%.
The more detail information about buckwheat burn virus you can also see on poster
presentation “Properties of buckwheat burn virus” Yuzvenko L., Lozova O. et al.

Plant defense
against viruses
• Stress conditions change typical protein
profile and trigger synthesis of pathogen-
related proteins.
• Nucleases are enzymes that hydrolyze nucleic
acids. The level of ribonucleases (RNases) can
increase greatly under stress conditions.
• Buckwheat varieties have different sensitivity
to buckwheat burn virus. The possible cause is
different activity i of plant RNases.

The aim of work
To analyze the correlation
between RNase activity it and
sensitivity of different
buckwheat varieties to
buckwheat burn virus

Experimental procedure
• We used buckwheat varieties with different sensitivity
to buckwheat burn virus: “Kara-Dag”
– injured by
virus, and “Roksolana” – slightly injured by virus.
• Plants were infected by buckwheat burn virus.
• The leaves were collected every 3 days after infection.
• Total RNase activity was detected by decreased
absorption at 260 nm.
• Reaction mixture without added RNase was used as
negative control. Reaction mixture added with RNase A
served as positive control.

Uninfected buckwheat
plants of two varieties
Absorp ption, А26 60
1,6
1,4
12 1,2
1
0,8
0,6
0,4
0,2
"Roksolana" variety
"Kara-Dag" variety
0
nega ative
con ntrol
RNa ase A
4
7
10
13
16
19
Days after infection of plants
High absorption value means low RNase activity, and vice versa.

Buckwheat plants of
“Kara-Dag” variety
Absor rption, А2 260
1,6
1,4
1,2
1
0,8
06 0,6
0,4
0,2
uninfected plants
infected plants
0
ne egative
co ontrol
RN Nase A
4
7
10
13
16
19
Days after infection i of plants
It was supposed that because of instable RNase activity especially during
It was supposed that because of instable RNase activity especially during
the first week “Kara-Dag” variety is injured by buckwheat burn virus.

Buckwheat plants of
“Roksolana” variety
Absorpti ion, А260 0
1,6
1,4
12 1,2
1
0,8
0,6
0,4
0,2
uninfected plants
infected plants
0
neg gative
con ntrol
RN Nase A
4
7
10
13
16
19
Days after infection of plants
I d h b f hi h RN i i d i k h i
It was assumed that because of high RNase activity during two weeks the virus
invasion is restricted, so “Roksolana” is only slightly injured by buckwheat burn virus.

Conclusions
• It was shown that buckwheat variety
having less sensitivity to buckwheat
burn virus demonstrated in general
higher RNase activity.
• Thereby we assume that RNase
activity level can be used as a test for
sensitivity of different buckwheat
varieties to virus infection.

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YOUR ATTENTION!