1021-4437/04/5102- © 2004
Russian Journal of Plant Physiology, Vol. 51, No. 2, 2004, pp. 194–197. From Fiziologiya Rastenii, Vol. 51, No. 2, 2004, pp. 217–221.
Original English Text Copyright © 2004 by Li-Jun Wang, Wei-Dong Huang, Ji-Cheng Zhan, Feng-Yi Yu.
Many protective mechanisms in plants were evolved
in order to cope with heat stress rapidly and properly.
SA, a phenolic compound, is a plant hormone with
ubiquitous distribution among plants and an ability to
regulate a large variety of physiological process in
plants . SA is an important endogenous signal
induced by heat stress, its level peaked within 30 min
after heat stress and induced resistance to heat stress in
mustard seedlings . The increase in the SA level
might result from (1)
SA synthesis in stressed
tissues; (2) SA release from conjugates and storage .
 studied the translocation and distribu-
tion of SA in tobacco seedlings with isotope technique.
Most SA detected in healthy tissues was synthesized in
the TMV-inoculated leaves; SA is a transported signal
of systemic acquired resistance in tobacco. Exogenous
SA moves mainly via the phloem [3–5]. When a part of
plant was stressed by heat, it is interesting to study
whether the increase in the SA level in this part
occurred because of the import from other parts of
plant. In this work, the translocation and distribution of
C-SA were studied in grape
plants in response to heat stress.
MATERIALS AND METHODS
Growth and treatment of plants.
Stem cuttings of
“Jingxiu” grape (
L.) were rooted in a
greenhouse under mist in pots containing a mixture of
4 peatmoss: 6 perlite (v/v). The rhizogenic cuttings
were planted into large pots and grown for 8–10 weeks
in the greenhouse with a relative humidity of 70–80%
C day/night cycle.
C-salicylic acid and heat stress.
was purchased from the NEN company (United States).
It was diluted with water and ethanol (2 : 8, v/v) to a
speciﬁc activity of 1.65 MBq/ml. From two-month-old
plants with similar growth, the leaves were cut except
the 4–8th leaves, i.e., leaves L4, L5, L6, L7, and L8
from top to base. Then L6 on each plant was washed
with sterile water, 35
C-SA (64750 Bq) was
smeared on it (Fig. 1). The plants were divided into four
groups. The following treatments were conducted: (I)
L4 was stressed at 38
C for 2 h, 6 h or 12 h, while other
parts were kept at 27
C; (II) L8 was stressed at 38
2, 6, or 12 h, while other leaves remained at 27
L6 was stressed at 38
C for 2, 6, or 12 h, while other
leaves remained at 27
C; (IV) all leaves were kept at
C for 2, 6, or 12 h (control treatment). Heat treat-
ments were conducted in a temperature-controlled
chamber, into which L4, L6, or L8 of grape plants was
placed, whereas other parts of plants were outside the
chamber and controlled at 27
C by air-conditioning.
RH (70–80%) and light intensity of 600
were the same outside and inside of the chamber. After
The Transport of
C-Salicylic Acid in Heat-Stressed Young
**, Wei-Dong Huang**, Ji-Cheng Zhan**, and Feng-Yi Yu***
*Institute of Botany, Chinese Academy of Sciences, Beijing, 100093 China
**College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100083 China;
fax: 8610-62-34-3863; e-mail:email@example.com
***Institute of Nuclear Application, Chinese Academy of Agricultural Science, Beijing, 100094 China
Received February 20, 2003
—The transport of salicylic acid (SA) in heat-stressed
plants was studied with
cylic acid. All leaves of young plants were cut off except the 4th, 5th, 6th, 7th, and 8th leaves. After the 6th
leaves were fed with
C-SA, the following treatments were conducted: (1) 4th, 6th, or 8th leaves were exposed
to a high temperature of 38
C for 2, 6, and 12 h, respectively, while other parts of plants were kept at 27
plants were kept at 27
C for 2, 6, and 12 h. The results showed that
C-SA accumulated in the leaves stressed
by heat. When the 6th leaves were at 38
C-SA was exported from these leaves than from control
leaves, but when the 4th or 8th leaves were kept at 38
C-SA was exported.
C-SA accumulation in
the 4th or 8th leaves resulted from the 6th leaves directly and from the other parts of plants indirectly. These
data suggested that SA was transported to a long distance and might be involved in the induction of heat toler-
Key words: Vitis vinifera - salicylic acid - heat stress - translocation - distribution - response
: RH—relative humidity; SA—salicylic acid;
SAR—systemic acquired resistance; TMV—tobacco mosaic virus.
This article was submitted by the authors in English.