ISSN 10214437, Russian Journal of Plant Physiology, 2011, Vol. 58, No. 1, pp. 142–148. © Pleiades Publishing, Ltd., 2011.
Phosphorus (P) is one of the most important nutri
ents for plant growth and development. The concen
tration of P in the soil solution is often as low as 2–10 mM
. Due to the low availability of soluble P in many
soils, plants developed morphological, physiological,
and molecular mechanism to tolerate low phosphate
availability . It is thought that these responses to
P starvation are coordinated by both general stress
related and Pspecific signaling cascades. Many genes
induced by P deficiency have been isolated and char
acterized to clarify the system of genetic regulation
underlying adaptation to P starvation. Transcription
elements related to the response to P deficiency have
been isolated ; however, the current knowledge is
not sufficient to explain the details of the network reg
ulating gene expression in response to low P.
This text was submitted by the authors in English.
) requires a sufficient
supply of P during early growth, and thus it is very sen
sitive to P deficiency. Its adaptation to P deficiency
includes highly coordinated modification of root
development and metabolism resulting in increased
roottoshoot ratios . Rapeseed roots exude large
amounts of organic acids (malic and citric acids) 
and phenols  into the soil. Concurrently, the expres
sion levels of citrate and phosphoenolpyruvate carbox
ylase are strikingly increased in Pstarved roots .
The transcription and activity of RNases  and acid
phosphatases  are enhanced by P deficiency. At
present, the molecular mechanisms of highly efficient
P utilization and genes induced by P starvation are not
very clear and need further study.
Analysis of expressed sequence tags (ESTs) is an
efficient approach for identifying large numbers of
plant genes expressed during different developmental
stages and in response to a variety of environmental
conditions . The objectives of this study were to
assess genes expressed in winter rape roots and leaves
and to analyze global gene expression in roots and
leaves under Pstarvation stress. To achieve this goal,
we (a) identified ESTs from roots and leaves in two dif
Differential Gene Expression in Leaves and Roots
of Winter Rape in Response to Phosphorus Starvation
, Ch. L. Zhang
, and B. Zhang
Crop Physiology and Sustainable Agriculture Division, Institute of Oil Crops Research,
Chinese Academy Agricultural Science, Wuhan, 430062 China;
Crop Research Institute, Shandong Academy of Agricultural Sciences, Jinan, 250100 China
HighTech Research Center, Shandong Academy of Agriculture Sciences, Jinan, 250100 China
Received January 6, 2010
—Genes induced by phosphorus deficiency in leaves and roots of winter rape (
lings were isolated and analyzed. The mRNA differential display technique was used to visualize cDNA frag
ments derived from the phosphorustolerant cv. Zy 821 and the phosphorussensitive cv. No. 1182 grown
under conditions of phosphorous starvation. Approximately 2000 cDNA bands were visualized by differential
display using 78 primer pair combinations. A total of 61 phosphorusstarvationinduced cDNA fragments
differentially expressed were isolated. Among these, 40 were derived from roots and only 21 from leaves.
Sequence analysis of 16 fragments revealed that they represented distinct cDNAs. A subsample of five cDNAs
was analyzed by semiquantitative RTPCR, which showed that they were truly different products. Tran
scripts coding for enzymes involved in photosynthesis (thylakoid membrane phosphoprotein) and root hair
initiation (xyloglucan endotransglycosylase), and two regulators (RNAbinding/nucleic acidbinding
mRNA and a structural constituent of ribosomal mRNA) were found to be differentially expressed. These
results show that the mechanism of cv. Zy 821 adaptation to P starvation is complex. Although its Ptolerance
trait is controlled by a major gene, many other genes influencing P acquisition and remobilization, carbon
and secondary metabolism, developmental processes, and regulatory pathways are also involved.
Keywords: Brassica napus
, DDRTPCR, phosphorus starvation, semiquantitative RTPCR, gene expression.
CA—carbonic anhydrase; DDRTPCR—differen
tial display reverse transcriptionPCR; EST—expressed sequence
tag; TF—transcription factor ; TMP14—14kD thylakoid mem
brane phosphoprotein; XET—xyloglucan endotransglycosylase.