Article Assignment Due date: December 11, 2012 by 1 pm Influence of aluminum on the uptake of various cations from a solution into carrots Read the article and answer the following questions: 1. What causes acidification of rain and what is the main effect of the acidification on crops? 2. Provide name of all elements that were utilized for preparation of multitracer solution. 3. Above what Al concentration was the deformation of carrot roots observed? At what AlCl3 concentration was the rate of cerium uptake into intact roots the highest? What is the pattern in uptake rate for rear earth elements? 4. What is the reported influence of Al3+ on the uptake of beryllium, strontium and barium by a carrot roots? What is responsible for this uptake? 5. Compare uptake of manganese, cobalt and zinc into roots and leaves at 0.002 ppm of Al. Answers to all questions must be typed. NOTE: You may need to find secondary sources to answer question 1. In such case, you must cite your sources at the end of the assignment, following the examples below. Remember that reproducing text from a source verbatim is plagiarism, and such incidences can become part of your academic record. How to cite a web page: National Library of Medicine. Environmental Health and Toxicology: Specialized Information Services. http://sis.nlm.nih.gov/enviro.html (accessed Aug 23, 2004). How to cite a scientific journal article: Evans, D. A.; Fitch, D. M.; Smith, T. E.; Cee, V. J. Application of Complex Aldol Reactions to the Total Synthesis of Phorboxazole B. J. Am. Chem. Soc. 2000, 122, 10033-10046. Effects of Ionic Valency of Interacting Metal Elements in Ion Uptake by Carrot (Daucas carota cv. U.S. harumakigosun) TAKUO OZAKI,*,1 SHIZUKO AMBE,2 YOSHITAKA MINAI,3 SHUICHI ENOMOTO,2 FUMIO YATAGAI,2 TOMOKO ABE,2 SHIGEO YOSHIDA,2 AND YOSHIHIRO MAKIDE4 1Japan Atomic Energy Research Institute, Tokai, Ibaraki, 319-1195, Japan; 2The Institute of Physical and Chemical Research (RIKEN), Wako, Saitama 351-0198, Japan; 3Faculty of Humanities, Musashi University, Toyotama-kami, Tokyo 176-8534, Japan; and 4Radio Isotope Center, Tokyo University, Yayoi, Tokyo 113-0032, Japan Received April 27, 2001; Accepted June 28, 2001 ABSTRACT Interaction of elements in the course of element uptake by carrot (Daucas carota cv. U.S. harumakigosun) exerted by the addition of ele- ments, such as Rb, Zn, and Al, was investigated. For the purpose of pre- cise evaluation of uptake behavior, the simultaneous determination of absorption of Na, Be, Sr, Mn, Co, Zn, Ce, Pm, and Gd was conducted by the multitracer technique. For root uptakes, Al exhibited its influence on the uptake of essential elements and on the uptake of toxic or unbenefi- cial ones, presumably as a result of the large electric valency that caused cell membrane disintegrity. On the other hand, Zn as a divalent cation only affected the uptake of essential and beneficial elements. Rubidium, which is a monovalent cation, did no ...

1. Article Assignment
Due date: December 11, 2012 by 1 pm
Influence of aluminum on the uptake of various cations from a
solution into carrots
Read the article and answer the following questions:
1. What causes acidification of rain and what is the main effect
of the acidification on crops?
2. Provide name of all elements that were utilized for
preparation of multitracer solution.
3. Above what Al concentration was the deformation of carrot
roots observed? At what AlCl3 concentration was the rate of
cerium uptake into intact roots the highest? What is the pattern
in uptake rate for rear earth elements?
4. What is the reported influence of Al3+ on the uptake of
beryllium, strontium and barium by a carrot roots? What is
responsible for this uptake?
5. Compare uptake of manganese, cobalt and zinc into roots and
leaves at 0.002 ppm of Al.
Answers to all questions must be typed.
NOTE: You may need to find secondary sources to answer
question 1. In such case, you must cite your sources at the end
of the assignment, following the examples below. Remember
that reproducing text from a source verbatim is plagiarism, and
such incidences can become part of your academic record.
How to cite a web page:
National Library of Medicine. Environmental Health and
Toxicology: Specialized Information Services.
http://sis.nlm.nih.gov/enviro.html (accessed Aug 23, 2004).
How to cite a scientific journal article:
Evans, D. A.; Fitch, D. M.; Smith, T. E.; Cee, V. J. Application
of Complex Aldol Reactions to the Total Synthesis of
Phorboxazole B. J. Am. Chem. Soc. 2000, 122, 10033-10046.

2. Effects of Ionic Valency
of Interacting Metal Elements
in Ion Uptake by Carrot
(Daucas carota cv. U.S.
harumakigosun)
TAKUO OZAKI,*,1 SHIZUKO AMBE,2 YOSHITAKA
MINAI,3
SHUICHI ENOMOTO,2 FUMIO YATAGAI,2 TOMOKO ABE,2
SHIGEO YOSHIDA,2 AND YOSHIHIRO MAKIDE4
1Japan Atomic Energy Research Institute, Tokai,
Ibaraki, 319-1195, Japan; 2The Institute of Physical and
Chemical Research (RIKEN), Wako, Saitama 351-0198, Japan;
3Faculty of Humanities, Musashi University, Toyotama-kami,
Tokyo 176-8534, Japan; and 4Radio Isotope Center,
Tokyo University, Yayoi, Tokyo 113-0032, Japan
Received April 27, 2001; Accepted June 28, 2001
ABSTRACT
Interaction of elements in the course of element uptake by
carrot
(Daucas carota cv. U.S. harumakigosun) exerted by the addition
of ele-
ments, such as Rb, Zn, and Al, was investigated. For the
purpose of pre-
cise evaluation of uptake behavior, the simultaneous

3. determination of
absorption of Na, Be, Sr, Mn, Co, Zn, Ce, Pm, and Gd was
conducted by
the multitracer technique. For root uptakes, Al exhibited its
influence on
the uptake of essential elements and on the uptake of toxic or
unbenefi-
cial ones, presumably as a result of the large electric valency
that caused
cell membrane disintegrity. On the other hand, Zn as a divalent
cation
only affected the uptake of essential and beneficial elements.
Rubidium,
which is a monovalent cation, did not exhibit any effect on the
uptake of
other ions. Concerning shoot uptakes, inhibition by Zn and Al,
but not
by Rb, was observed for the uptake of Sr, Mn, Co, and Zn. From
the pres-
ent investigation, it is suggested that there exists an interaction
between
added ions and the elements taken into plants and that the
degree of
Biological Trace Element Research 197 Vol. 84, 2001
© Copyright 2001 by Humana Press Inc.
All rights of any nature, whatsoever, reserved.
0163-4984/01/197–211 $13.75
*Author to whom all correspondence and reprint requests should
be addressed.
interaction increases in the increasing order of ionic valency:

4. M+ (Rb),
M2+ (Zn), and M3+ (Al).
Index Entries: Ion uptake; ionic valency; interaction; metal;
muti-
tracer; toxic effect; Daucas carota.
INTRODUCTION
Generally, there exists a significant gap between nutrient
concentra-
tions in soil or nutrient solution and the nutrient requirement of
plants.
Soil and, in some cases, nutrient solutions may contain very
high concen-
trations of nutrient elements, exceeding the capacity for
appropriate
uptake balance. Therefore, various effects can be caused when
plants are
exposed to unfavorable concentrations of more than one
element. Alu-
minum and Mn toxicity in plants, for example, is a serious
problem, which
is caused by acidic rain. It was elucidated that Al inhibits Ca
uptake by
blocking Ca2+ channels in the plasma membrane (1) and
inhibits Mg
uptake by blocking binding sites of transport proteins (2). High
concentra-
tions of Mn2+ also inhibit Ca and, in particular, Mg uptake (3).
Leaching of
metals from mining sites can also be a serious problem. An
excess amount
of Cu was demonstrated to be an inhibitor for the uptake of Zn,
affecting
plasma membrane–H+ ATPase activity (4). A study on the ion-

5. competition
effects on the uptake revealed that the uptake of elements, in
general,
decreases with an increase in the concentration of nutrient
solution (5).
For the uptake of ions from the soil or nutrient solutions into
the cyto-
plasm, the first important step is the binding of ions at the
transport sites
in the plasma membrane. In the external solution, both cations
and anions
are present in different concentrations and forms. Various
interactions
between ions during their uptake are therefore to be expected.
Competi-
tion between ions, particularly those with similar physical and
chemical
properties, is expected, assuming that the number of the sites is
small com-
pared to that of competing ions. For example, arsenate and
phosphate are
taken up by the same transport system in plants (6). The
examples of
strong competition between K+ and Rb+ and between anions
such as SO42–
and SeO42– demonstrate that the selectivity of the binding sites
in plasma
membranes is not a reflection of the function of a particular
nutrient ele-
ment in plant metabolism, but only a reflection of the
physicochemical
similarities between ions that are plant nutrients (e.g., K+ and
SO42–).
Plants are thus unable to exclude unrequired ions from uptake.
Most of all,

6. the driving force for each element to be attracted to the sites is
electrostatic
power; therefore, electric valency is considered to be an
important factor
for competition, particularly in the early process of ion uptake
when the
biological toxic effect need not be taken into consideration. As
a general
rule, the strength of interaction toward membrane constituents,
such as
phospholipids and sulfolipids, and proteins is known to increase
in the fol-
lowing order:
198 Ozaki et al.
Biological Trace Element Research Vol. 84, 2001
Uncharged molecules < M+ < M2+ < M3+
Conversely, the uptake rate often decreases in this order,
suggesting
some role of ionic valency of interacting elements in ion uptake
by plants.
The multitracer technique was developed by Ambe et al. using
the
RIKEN Ring Cyclotron, which opened a new field in
radiochemistry,
namely simultaneous tracing of the behavior of various elements
(7–9). By
virtue of the high performance of the RIKEN Ring Cyclotron,
ion beams,
such as 12C or 14N, can be accelerated up to 135 MeV/nucleon,

7. which is
sufficiently strong to cause fragmentation reactions in target
metals.
Application of this technique allows us to observe the behavior
of various
elements at the same time. This is of great advantage, especially
for bio-
logical samples from the point of view that biological samples
are always
accompanied with relatively large individual differences, and
metal toxic-
ity is not necessary to be taken into consideration because
multitracers are
in a carrier-free state. The usability of this technique has been
demon-
strated in plant research (5,10–15).
This study was conducted in an attempt to evaluate the effects
of
valency of added metal cations on the uptake of various
elements by car-
rot. In this investigation, Al, Zn, and Rb were chosen as
representatives for
trivalent, divalent, and monovalent ions, respectively.
MATERIALS AND METHODS
Preparation of Plant Samples
Carrot (Daucas carota cv. U.S. harumakigosun) was selected as
a sam-
ple species, because it thrives well in a hydroponic culture and
grows
quickly. Surface sterilized seeds of carrot were germinated on
filter paper
and afterward the seedlings were grown on Kureha Horticulture

8. soil,
purchased from the Kureha Chemical Industry Co., Tokyo., for
20 d in a
growth chamber under the controlled climatic conditions
(day/night
16/8 h; light intensity: 150 µmol/m2/s; temperature: 25±2°C;
relative
humidity: 70–80%). The plant samples of approximately 7 cm in
length
were transplanted to ultrapurified water and maintained there
for 3 d
with constant bubbling of air under the same photoperiod and
tempera-
ture as above. For the purpose of minimizing the effect of the
adherent
soil and of injury to root surfaces caused by transplantation, the
ultrapu-
rified water was changed every several hours. Additional details
are
described in the literature (16,17).
Preparation of a Multitracer
Solution
A 300-µm-thick Au plate was irradiated with a 135-
MeV/nucleon 12C or
14N ion beam accelerated by the RIKEN Ring Cyclotron. The
irradiated Au

9. target containing various kinds of radioisotope was dissolved in
aqua regia
Effect of Ionic Valency on Metal Ion Uptake 199
Biological Trace Element Research Vol. 84, 2001
and this acid solution was evaporated to near dryness. After the
residue was
dissolved in 1.5 mol/dm3 HCl, a Au ion was completely
extracted with ethyl
acetate, leaving the radioisotopes as a multitracer in carrier- and
salt-free
states. Additional details are described in the literature (9).
Preparation of Al, Zn, and Rb