ISSN 10214437, Russian Journal of Plant Physiology, 2010, Vol. 57, No. 1, pp. 96–100. © Pleiades Publishing, Ltd., 2010.
Original Russian Text © N.A. Soldatova, V.N. Khryanin, 2010, published in Fiziologiya Rastenii, 2010, Vol. 57, No. 1, pp. 103–107.
According to endo/ectogenic theory [1, 2], sex
determination and differentiation depend on both
internal and external factors. Plant sex determination
is based on plant genetics, whereas its expression
depends on both the genotype and environmental fac
tors (mineral nutrition, water relations, temperature,
gas composition in atmosphere, and illumination).
External factors affect numerous physiological and
biochemical processes characterizing plant sex .
Their action is especially strong in the period of tran
sition from vegetative to reproductive development.
Thus, for dioecious plant marijuana, such a crucial
phase is the phase of three true leaves . It has been
shown that GA and cytokinins, along with auxins,
ABA, and ethylene, play a decisive role in sexualiza
tion of many plant species. The interaction between
these phytohormones, on the background of the com
mon hormonal balance, is an important factor of sex
ual status of such plants.
Numerous investigations performed on diverse
plant species (
, and others)
demonstrated GAinduced plant masculinization [5–
8] and cytokinininduced feminization . However,
BA and GA effects on sex expression were not found
for some dioecious plants . In the case of marijuana,
it has been reliably shown that GA action is related to
male sex expression and cytokinin action, with female
sex expression . In Nature, the ratio between mar
ijuana sexes equal to a unity. Plant growing under nat
ural or experimental conditions could shift sex expres
sion substantially. Ecological factors affect the hor
monal balance in marijuana plants; phytohormones
interact with the genetic apparatus and thus determine
sex expression [10, 11].
It was repeatedly reported that external stressors
affect phytohormone content in plants and their ratios
: elevated  and lowered  temperatures,
UVB radiation , salinity [14, 16–18], etc. Biolog
ically active compounds (for example, synthetic ana
logs of phytohormones) were shown to weaken heavy
metal (HM) toxicity . However, as far as we know,
there is no information about HM effects on phyto
hormonal status and sex expression in plants.
The objective of this work was to analyze the effects
, and ZnSO
not only on mor
phological, physiological, and biochemical processes
but also on the content of phytohormones and sex
expression in various cultivars of marijuana dioecious
MATERIALS AND METHODS
Various cultivars of dioecious
plants were analyzed: earlyripening cv. Kubanskaya
rannyaya, middleripening cv. Zenitsa, and lateripen
ing cv. Slavyanka.
In control, seeds were germinated and plants were
grown on Knop nutrient medium with lowered level of
The Effects of Heavy Metal Salts on the Phytohormonal Status
and Sex Expression in Marijuana
N. A. Soldatova and V. N. Khryanin
Department of Botany, Plant Physiology and Biochemistry, Penza State Pedagogical University, ul. Lermontova 37,
Penza, 440026 Russia;
emails: firstname.lastname@example.org; email@example.com
Received November 28, 2008
—We studied the effects of heavy metal salts (Pb(NO
, and ZnSO
) on phytohormonal
status and sex expression in various cultivars of marijuana (
L.), a dioecious plant, grown on
Knop nutrient medium. Pb(NO
were added to the medium at the concentration of 10
, at the concentration of 10
M. Plant were grown under controlled conditions at luminescent
C, and 80% humidity. The contents of GA and zeatin were determined by HPLC. Cop
per and zinc salts induced plant feminization, and this effect was coupled with zeatin accumulation. Lead
salts favored plant masculinization coupled with GA accumulation. Thus, a shift in sex expression in mari
juana plants was correlated with the heavy metal action on the balance of phytohormones, GA and zeatin.
Key words: Cannabis sativa heavy metals phytohormones sex expression
; BA—benzyladenine; HM—heavy metals.