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"The effluent takes five days to wind from one end of the greenhouse to
the other. When it reaches the far end, it is filtered by the artificial
marsh - a gravel bed out of which grows a carefully selected thicket of 
water-loving plants. The marsh plants are chosen because they have 
commercial value (watercress) or pretty blooms (marsh marigold) or known
ability to take up toxic substances (cattails, bulrushes). Organic toxins
are broken down. Heavy metals accumulate in the plants and in any compost
made from the plants. That's a problem, but heavy metals are a problem in
every kind of wastewater treatment plant."
"I learned about these plants from Kathe Seidel at the Max Planck
Institute in West Germany. She's tested 260 plants for purifying ability.
She found that some would take up heavy metals and organic solvents and
even some, like that aquatic iris over there, that exude substances from
their roots that kill pathogenic bacteria. Hardly anyone pays attention to
her work. But she gave me the confidence that we could duplicate nature's 
way of making high-quality water."

 

-------
Article 11236 (123 more) in rec.gardens:
From: dietz@cs.rochester.edu (Paul Dietz)
Subject: Hyperaccumulators?
Date: Tue, 6 Oct 1992 23:15:20 GMT

I just was reading a bit about some plants that are
"hyperaccumulators": they concentrate normally toxic metals in their
tissue to an amazing extent (for example, plants that grow on soils
derived from ultramafic rocks that concentrate nickel in their leaves
to > 3% of their dry weight).  Are there any plants normally grown in
gardens that are hyperaccumulators?

        Paul F. Dietz
        dietz@cs.rochester.edu

Article 11244 (116 more) in rec.gardens:
From: klier@iscsvax.uni.edu

In article <1992Oct6.231520.20515@cs.rochester.edu>, 
dietz@cs.rochester.edu (Paul Dietz) writes:

> I just was reading a bit about some plants that are
> "hyperaccumulators": they concentrate normally toxic metals in their
> tissue to an amazing extent (for example, plants that grow on soils
> derived from ultramafic rocks that concentrate nickel in their leaves
> to > 3% of their dry weight).  Are there any plants normally grown in
> gardens that are hyperaccumulators?

To the best of my knowledge, no.  Though you will see such things as
lead accumulating in root crops like carrots.

Most of the "ultra accumulators" are things like locoweeds, which
pick up selenium in sulfur-poor soils, and you actually get selinium
containing amino acids and proteins (i.e., the selenium "spares" the
sulfur).

There is a cute S. African plant I've read of called "giftboom" (poison
tree) that does something rather spectacular with fluorine, which I've
now forgotten.  Maybe uses Fl- instead of Cl-?????

Kay Klier  Biology Dept  UNI

Article 11254 (121 more) in rec.gardens:
From: dietz@cs.rochester.edu (Paul Dietz)
Subject: Re: Hyperaccumulators?
Date: Wed, 7 Oct 1992 11:52:31 GMT

In article <1992Oct6.205925.7361@iscsvax.uni.edu> klier@iscsvax.uni.edu writes:

> There is a cute S. African plant I've read of called "giftboom" (poison
> tree) that does something rather spectacular with fluorine, which I've
> now forgotten.  Maybe uses F- instead of Cl-?????

"Gifblaar".  It makes fluoroacetate ion, a potent inhibitor of the
Krebs cycle.  One mouthful of this plant can kill a sheep.  A related
species makes some other fluorinated acids, also toxic.

Interestingly, another member of this genus is a nickel
hyperaccumulator.

        Paul F. Dietz
        dietz@cs.rochester.edu

Article 11287 (153 more) in rec.gardens:
From: emolinar@stake.DaytonOH.NCR.COM (Elizabeth Molinaro)
Subject: Re: Hyperaccumulators?Date: 7 Oct 92 18:29:15 GMT

In article <1992Oct6.205925.7361@iscsvax.uni.edu> klier@iscsvax.uni.edu
writes:
>In article <1992Oct6.231520.20515@cs.rochester.edu>, dietz@cs.rochester.edu
(Paul Dietz) writes:
>> 
>> I just was reading a bit about some plants that are
>> "hyperaccumulators": they concentrate normally toxic metals in their
>> tissue to an amazing extent (for example, plants that grow on soils
>> derived from ultramafic rocks that concentrate nickel in their leaves
>> to > 3% of their dry weight).  Are there any plants normally grown in
>> gardens that are hyperaccumulators?
>
>To the best of my knowledge, no.  Though you will see such things as
>lead accumulating in root crops like carrots.
>

        I read something about Jimsonweed.

        About a month ago, in the Wall Street Journal, page 1

        Apparently, it hyperaccumulates toxic nuclear (now THAT's
        redundant) wastes...and thrives!!!!

        Elizabeth


From: klier@iscsvax.uni.edu
Subject: re: Hyperaccumulators
Date: 8 Oct 92 18:35:08 -0500

Paul Dietz (with a marvelous memory!) remembered the plant I couldn't--
the one that makes fluoroacetate when grown on soils heavy in fluorine,
and thus becomes toxic to animals.  He also remembered the common name
is "giftblaar", not "giftboom" as I had thought.

Dichapetalum is a BIG genus of 150-200 species of the tropics, particularly
Africa.  It's a member of the family Dichapetalaceae, which may be
related to the Euphorbiaceae, the poinsettia family, according to 
Willis's Dictionary.  Alas, Chiltern Seeds doesn't seem to stock it :-(

------
From:   IN%"dietz@cs.rochester.EDU"  

The genus is Dichapetalum.  The three species to which I referred
are:

        D. cymosum      Makes fluoroacetate
        D. toxicarium   Makes various omega-fluorinated fatty acids
        D. gelonioides  A nickel hyperaccumulator

D. gelonioides doesn't have unusually large amounts of fluorine in
its tissues.  I don't remember if D. toxicarium makes fluoroacetate
as well.
--------

Hi ho, hi ho, it's off to the library I go... 8-)

Kay

rec.gardens #10472 
From: A.S. Chamove
Re: Hyperaccumulators
Date: Sun Oct 11 19:47:12 1992
Organization: Massey University, Palmerston North, New Zealand

Does anyone know of a plant (edible to cows and horses) that will
concentrate selenium in selenium-deficient soils?

Arnold Chamove
Massey University Psychology
Palmerston North, New Zealand


1] Re: Hyperaccumulators
Date: Sun Oct 11 20:53:28 1992
Organization: University of Northern Iowa

In article <1992Oct11.234712.18978@massey.ac.nz>, 
A.S.Chamove@massey.ac.nz (A.S. Chamove) writes:
> Does anyone know of a plant (edible to cows and horses) that will
> concentrate selenium in selenium-deficient soil?
> 

Species of _Astragalus_ and _Oxytropis_ are notorious for this in low-
sulfur soils.  Of course, when the horse or steer gets too much
Se from the locoweeds, you see "moonblindness" and other neurological
symptoms.

Kay


rticle 11244 (116 more) in rec.gardens:
From: klier@iscsvax.uni.edu
ubject: Re: Hyperaccumulators?
Date: 6 Oct 92 20:59:25 -0500

In article <1992Oct6.231520.20515@cs.rochester.edu>, dietz@cs.rochester.edu (Pau l Dietz) writes:
> 
> I just was reading a bit about some plants that are
> "hyperaccumulators": they concentrate normally toxic metals in their
> tissue to an amazing extent (for example, plants that grow on soils
> derived from ultramafic rocks that concentrate nickel in their leaves
> to > 3% of their dry weight).  Are there any plants normally grown in
> gardens that are hyperaccumulators?

To the best of my knowledge, no.  Though you will see such things as
lead accumulating in root crops like carrots.

Most of the "ultra accumulators" are things like locoweeds, which
pick up selenium in sulfur-poor soils, and you actually get selinium
containing amino acids and proteins (i.e., the selenium "spares" the
sulfur).

There is a cute S. African plant I've read of called "giftboom" (poison
tree) that does something rather spectacular with fluorine, which I've
now forgotten.  Maybe uses Fl- instead of Cl-?????

Kay Klier  Biology Dept  UNI


Article 11249 (115 more) in rec.gardens:
From: london@SunSite.unc.edu (Larry London)
Subject: Re: Hyperaccumulators?
Date: Wed, 7 Oct 1992 05:06:58 GMT

In article <1992Oct6.231520.20515@cs.rochester.edu> 
dietz@cs.rochester.edu (Paul  Dietz) writes:
>
>I just was reading a bit about some plants that are
>"hyperaccumulators": they concentrate normally toxic metals in their
>tissue to an amazing extent (for example, plants that grow on soils
>derived from ultramafic rocks that concentrate nickel in their leaves
>to > 3% of their dry weight).  Are there any plants normally grown in
>gardens that are hyperaccumulators?
>
>       Paul F. Dietz
>       dietz@cs.rochester.edu

A lady in Germany has researched and catalogued some 250 or so plants
identified as hyperaccumulators. I have a magazine article on John Todd's
experiments with biological sewage treatment systems using some of these
plants along with certain aquatic animals, in partitioned lagoons, in
greenhouses to produce acceptably clean effluent. John started the New
Alchemy Institute.
Datura (Jimson Weed) and cattails are reputed to be hyperaccumulators.


Date: 12 Oct 92 00:53:28 GMT
Organization: University of Northern Iowa

In article <1992Oct11.234712.18978@massey.ac.nz>, 
A.S.Chamove@massey.ac.nz (A.S. Chamove) writes:
> Does anyone know of a plant (edible to cows and horses) that will
> concentrate selenium in selenium-deficient soil?

Species of _Astragalus_ and _Oxytropis_ are notorious for this in low-
sulfur soils.  Of course, when the horse or steer gets too much
Se from the locoweeds, you see "moonblindness" and other neurological
symptoms.

Kay

Article 471 (7 more) in bionet.plants:
Organization: Penn State University
Date: Tue, 20 Oct 1992 15:48:56 EDT
From: <MEK104@psuvm.psu.edu>
Subject: Re: Heavy Metals and Fruit Trees

cpotter@ncsa.uiuc.edu (Clint Potter) Date: Mon, 19 Oct 1992 19:09:08 GMT
Requested info:

> I am after a information on the effects of heavy metals in the soil on fruit
> trees.

> Are metals like Pb and Cd detrimental to the growth of trees like apples,
> peaches and pears?  Is there any research on tolerable concentrations of
> these elements?  Are these metals likely to migrate to the fruit?  What type
> of soil test should be done?  Is total Pb and total Cd adequate?

> Thank you for any information or references.

> Clint Potter cpotter@ncsa.uiuc.edu

Check a recent review article :

       W. H. O. Ernst et al., 1992.  Metal tolerance in plants.
       Acta Botanica Neerlandica 41:229-248.

If it doesn't provide you with the info you need, it may lead you to other
sources in the literature cited.

Mark Kubiske

From: bj368@cleveland.Freenet.Edu (Mike E. Romano)
Subject: Re: Aquaculture
Date: 20 Oct 1992 09:29:30 GMT
Organization: Case Western Reserve University, Cleveland, Ohio (USA)

  In reference to Larry London's request for further cites of
publications by New Alchemy and on the subject of 
bioremediation, I have the following from my files:

Solar Aquaculture: perspectives in renewable, resource based
fish production, results for a workshop at Falmouth, Mass.
Sept 28, 1981  supported by the National Science Foundation
New Alchemy Institute.

Bioremediation for marine oil spills.  U.S. Gov Doc.  Office
of Technology Assessment  1991
doc # Y 3.T 22/2:2 B 52.7

Bioremediation of contaminated surface soils by Sims &
Matthews.   EPA  1989    EP 1.23/6:600/9-90/041

National Conference on Bioremediation (1988).  Hazardous
waste treatment by genetically engineered or adapted 
organisms.  Superfund '88.  Silver Springs, MD

Bioremediation of petroleum spills in arctic environments.
Alaska Dept of Transportation  1990

Understanding Bioremediation: a guidebook for citizens.
EPA  1991    doc  EP 1.8:B 52/2

Quick Bibliography Series # 92-47.
Biotechnology and Bioremediation.  National Agricultural
Library   Beltsville MD  1991

Practical environmental bioremediation.  Barry King  
Lewis Publishing   1992.

-- 
Capt. Kirk: let's head for that planet, third from the sun, it
            looks promising.... |-)

Article 704 in bionet.plants:
Organization: Penn State University
Date: Fri, 11 Dec 1992 09:03:23 EST
From: <MEK104@psuvm.psu.edu>


Subject: Re: Heavy metals in plants
Lines: 24

I'm out of my field here, but I'm somewhat involved in a study here at Penn
State which might at least be interesting, if not relevant to this budding
'heavy metal' discussion.  About 100 years ago in the Eastern US, the
"cahrcoal-iron" industry was pretty big business.  Travelers through
Pennsylvania can still see the huge, stone iron furnaces in state parks and
the like.  The iron workers would fire the furnaces with charcoal which they
produced themselves from the surrounding forests.  One can walk through the
woods almost anywhere in PA and encounter numerous "charcoal hearths" -
elliptical or circular flat areas about 10 to 12 meters across with very
little or no woody vegetation.  The study was designed to try and pin down
why woody vegetation is virtually excluded from these hearths even after 100
years.  I might add that the surrounding woods were heavily logged during
this period, clearcut on 40 year rotations was common.  Needless to say the
woods are growing quite vigerously, but not the hearths.  Tissue-water
relations of test plants (my field) suggest some form of drought stress.
The soil on these hearths is up to 70% organic matter due to charcoal dust
--MORE--(83%)

and fragments.  Can there be some heavy metal residue that may have been
concentrated by stacking 10 cords at a time on these hearths and coaling
them?  Some hearths were used very many times over.

Mark Kubiske                < MEK104@PSUVM.PSU.EDU >
School of Forest Resources
Penn State University

End of article 704 (of 704)--what next? [npq] 


Article 708 (1 more) in bionet.plants:
From: BOTSALT@VM.UOGUELPH.CA (david salt)


Subject: heavy metals a few points
Date: 11 Dec 92 22:14:04 GMT
Distribution: bionet
Lines: 31

Well I am pleased with the response to my plea for discussion on the topic
of heavy metals and plants.
The discussion on hyperaccumulators is interesting but it is important to
realise that to my knowledge there is no example of a plant which excludes
metals, all plants appear to accumulate metals to some degree. This is probably
due to the cationic metal being driven across the PM via the membrame potential
-ve inside. In tobacco this metal then appears to be compartmentalised within
the vacuole. Once inside the vacuole Cd is bound to the induced peptide
phytochelatins, therebye reducing the Cd's chemical gradient across the
tonoplast and hence reducing the amount of energy required to keep pumping
Cd inside. In oats Cd is transported across the tonoplast via a Cd/H
antiport (presumably driven in vivo by tghe tonoplast H-ATPase or H-PPiase).
Transport of Cd back out across the PM may also be a possibility.
RE Datura: P. Jackson at Los Alamos has done alot of work on the
biochemistry of Cd resistence on Datura innoxia in tissue culture!

--MORE--(64%)

IS CADMIUM REALLY SO BAD!!!!!!
a recent article in Nature suggests not!(344, 658-660, 1990)
It would appear that Cd can substitute for Zn in Zn deficient marine diatoms!
Does this explain the slight growth stimulation physiologist have seen (but
not talked about) in Cd tolerence tests using root elongation?
What is Cd doing in the marine diatom? Is it siting in the active site of
catalase or in Zn-fingers?....Any ideas.

Finally are there any biophysicists out there how can explain to me why
crystaline CdS is an interesting semiconductor because the fission yeast
S. pombe makes particles of it when exposed to Cd (and may be also plants)
and AT&T Bell laboratories are interested (Nature 338, 596-597, 1989).

David Salt
Botsalt@vm.uoguelph.ca
End of article 708 (of 709)--what next? [npq] 710
Article 710 in bionet.plants:
From: claird@NeoSoft.com (Cameron Laird)


Subject: Re: A big hello
Date: 11 Dec 92 14:49:21 GMT
Distribution: bionet
Organization: NeoSoft Communications Services -- (713) 684-5900
Lines: 34

In article <1992Dec10.234216.8446@gserv1.dl.ac.uk> london@sunsite.unc.edu (Larry
 London) writes:
>In article <1992Dec10.153700.17634@gserv1.dl.ac.uk> you write:
>>In article <92129225625.MIN-LVLBa00330.bionet-news@uk.ac.daresbury> you wrote:
                        .
                        .
                        .
>>: Is there anybody out there who is interested in how plants deal with
>>: heavy metals (ie Cd, Cu, Zn etc....yes O.K you know what a heavy metal
>>: is). Perhaps were could have a meaningful dialogue?
>>
>>I worked for a while at Plymouth Polytechnic (UK) during the early 80's
>>when Lane and Martin were working on uptake of heavy metals by potatos
>>and strawberries, but I'm not sure what they published.
                        .
--MORE--(59%)

                        .
                        .
>Here's a thread on the subject I've saved over the past several months.
>There is additional material contained in a number of posts in
>alt.sustainable.agriculture, which I've archived. These mostly relate to
>the work of John Todd, formerly of the New Alchemy Institute.
A paper by K. C. Jones et al., *Nature*, 356, 137, 1992,
analyzes secular trends in pollution around Rothamsted
by measuring plants' incorporated burdens of different
pollutants.  The authors' principal concerns were with
organics--PCBs, hydrocarbons--but I think their biblio-
graphy touches on metal uptakes.
                        .
                        .
                        .
-- 

Cameron Laird
claird@Neosoft.com (claird%Neosoft.com@uunet.uu.net)    +1 713 267 7966
claird@litwin.com (claird%litwin.com@uunet.uu.net)      +1 713 996 8546
End of article 710 (of 713)--what next? [npq] 713
Article 713 in bionet.plants:
From: ajt@rri.sari.ac.uk (Tony Travis)


Subject: Re: Plant communication/sensing references wanted
Date: 12 Dec 92 23:23:45 GMT
Distribution: bionet
Organization: Rowett Research Institute
Lines: 20
Original-To: plantbio@uk.ac.daresbury

In article <921212201751.MIN-LVICa00330.bionet-news@uk.ac.daresbury> you wrote:
: 
:    The subject about says it all: I'm interested in references to literature
:    which explores the capabilities of the plant world with refer712
Article 712 in bionet.plants:
From: ajt@rri.sari.ac.uk (Tony Travis)


Subject: Re: heavy metals a few points
Date: 12 Dec 92 23:18:36 GMT
Distribution: bionet
Organization: Rowett Research Institute
Lines: 26
Original-To: plantbio@uk.ac.daresbury

In article <921211224901.MIN-LHFCa00330.bionet-news@uk.ac.daresbury> you wrote:
: [...]
: The discussion on hyperaccumulators is interesting but it is important to
: realise that to my knowledge there is no example of a plant which excludes
: metals, all plants appear to accumulate metals to some degree. This is probabl
y
: due to the cationic metal being driven across the PM via the membrame potentia
l
: -ve inside. In tobacco this metal then appears to be compartmentalised within
: [...]

I did some work with benzo-18-crown-6 (a synthetic ionophore) which
demonstrated that accumulation of K+ in the vacuole of stomatal guard
cells was dependent on the permeability of the PM to K+ ions.  The
--MORE--(66%)

crown ether is incorporated into the membrane and forms K+ permeable
channels.

The driving force for accumulation of K+ is electrogenic proton
extrusion across the PM/tonoplast.  It seems that accumulation of Cd or
any other cation available would depend on membrane permeability rather
than active transport of the metal itself.

        Tony.
--
Dr. A.J.Travis,                       |  Tony Travis
Rowett Research Institute,            |  JANET: <ajt@uk.ac.sari.rri>
Greenburn Road, Bucksburn,            |  other: <ajt@rri.sari.ac.uk>
Aberdeen, AB2 9SB. UK.                |  phone: 0224-712751
End of article 712 (of 713)--what next? [npq] Article 721 (1 more) in bionet.plants:
From: donachie@vax.oxford.ac.uk


Subject: Heavy metals
Date: 14 Dec 92 13:13:24 GMT
Organization: Oxford University VAX 6620
Lines: 20


 
 On the subject of hyperaccumulators, work in this lab is investigating the
nature of the complexes formed in these plants with organic acids, in order to
determine whether these provide a possible mechanism of tolerance for the
plant.  

  The levels of metal which these plants accumulate can be huge, Sebertia
accuminata, a tree from New Caledonia, has a latex which conatins, on a dry
weight basis, 26 % nickel.  This is the highest recorded concentration in any
living ( :-) ) organism.  

  I think that the act of hyperaccumulation is related to the site at which the
plant can be found.  We are working on Alyssum spp here, and these can be, and
are regularly grown in gardens in Europe.  We have plants which are known to be
hyperaccumulators, and as control plants we are using garden seeds bought from
--MORE--(88%)

a commercial supplier.  We think that they won't hyperaccumulate, if they do
then....

  Just some interesting info to pass on over the dinner table ( :-) )
End of article 721 (of 722)--what next? [npq] Article 723 in bionet.plants:
From: cunninsd@esvax.dnet.dupont.com


Subject: plants, metals and contaminated sites
Date: 15 Dec 92 15:55:43 GMT
Distribution: bionet
Lines: 98


        This is my first time on this network, but I heard a
discussion of heavy metals in plants was underway, so I 
thought I'd join in. Here at DuPont we have an active 
research program in using plants toremediate contaminated 
soils. For this effort we  have borrowed a term I first heard
used by Ilya Raskin at Rutgers' and called it 
"Phytoremediation". 

        We define phytoremediation as the use of green plants to
remove, contain, or render harmless an environmental 
contaminant.  This definition applies to all plant-influenced
biological, chemical, and physical processes that aid in site
remediation. Although our particular current research 
emphasis is the remediation of lead-contaminated soils, we 
are interested in most other metals and organics as well.  
--MORE--(20%)

Simply described, we propose to farm hazardous waste sites, 
biomine the metal contaminants, and reclaim the metals 
through postharvest processing of the biomass. We consider 
the entire process to have multiple, but interdependent 
components. For the technology to be useful each component 
must be sound technically and economically, and must be 
acceptable from a regulatory perspective. Our efforts in 
phytoremediation of lead-contaminated soils address all of 
these areas. I thought I would venture some general comments
on the area and see what reaction they brought.

        Although metal tolerant plants are relatively common, 
most do not accumulate significant quantities of metal in the
above ground biomass. Our metal-removal goals are ambitious,
paralleling removal rates of plant nutrients such as 
nitrogen, potassium, and calcium.  For plant-based 
decontamination to be sucessful, we must find, breed or 
engineer plants that absorb, translocate and tolerate these
metals. These three processes are separate, distinct and, in
some plants, mutually exclusive.(ie tolerance can be obtained
by lack of translocation etc.) We have found that 
combinations of any two processes in one plant are relatively
easy to find.  All three processes, working efficiently in a 
--MORE--(43%)

single plant with sufficient biomass to acheive the necessary 
metal-removal rates, will be more difficult to achieve. 

        The discovery or development of such plants might be 
assumed to be infeasible if it were not for the existence of
the hyperaccumulators that have been mentioned on this 
network. These naturally-occurring plants can be found 
growing on ore outcroppings and have spectacular metal-uptake
capacities. The sap of one tree has been mentioned previously
to have concentrations of Ni in excess of 25% dry weight. 
Alan Baker (Sheffield) lists plants with concentrations in 
excess of 1%  Cu and Co and 3% Zn, Ni, and Mn on a dry weight
basis.  Lead levels, although lower,  have been reported as 
high as 8,200 ppm in these plants. We are looking at these 
hyperaccumulators for potential remediation uses, however, 
due to their low growth habits and small biomass, they would
seem to be agronomically and climatically unsuited for 
phytoremediation of most sites. A breeding program to 
increase biomass and metals content is a long-term, crop-
development strategy that could be undertaken. Molecular 
biology, however, may offer valuable shortcuts !!! - (Check 
with your patent attorney, before you release it as this 
plant can have real and significant value)
--MORE--(67%)


        Parallel to our efforts with hyperaccumulators, we have
been exploring lead-contaminated sites for plants that 
accumulate lead. Our goal is to find, manipulate, and extend
the lead-uptake limits of these plants. We have collected and
analyzed many plants from Superfund, mining, and other
industrial sites in search of appropriate germplasm. Of the
plants we have analyzed to date, two plants have shown 
significant abilities to accumulate lead. These are hemp 
dogbane (Apocynum sp.) and common ragweed (Ambrosia sp.). 
Their lead accumulation abilities are considerable, but not 
consistent, however, across soils. Most metals, and lead in 
particular, have numerous forms in the soil, not all of which
are equally available for plant uptake.

        Manipulating the chemistry of the soil to maximize lead
removal requires balancing plant-nutritional requirements for
biomass production with the availiability of lead for uptake
by plants. We have found these to be often competing 
processes. Maximizing lead availability requires a lower pH 
and low solution levels of phosphate and sulfate, which 
directly impacts total plant biomass produced. The plant-
nutritional status of the soil must be continuously balanced
--MORE--(89%)

against the lead-availability status to maximize total lead 
removal.

        Pb occurs in all of the physicochemical forms measured
in a sequential extraction of contaminated soils, including
water-soluble, exchangeable, specifically adsorbed, 
carbonate, oxyhydroxide, organic, and other forms.  
Experiments have confirmed, however, that there are wide 
differences between soils in these Pb forms and in the 
ability of plants to pick up the metal in question.

        I would be interested in general comments on the 
approach, names of others working in the area, etc. etc..
End of article 723 (of 724)--what next? [npq] 727
Article 727 (2 more) in bionet.plants:
From: dr@ducvax.auburn.edu


Subject: Re: A big hello
Lines: 28
Nntp-Posting-Host: ducvax
Organization: Auburn University, AL
Distribution: bionet
Date: Wed, 16 Dec 1992 06:32:56 GMT
Lines: 28

In article <1992Dec10.153700.17634@gserv1.dl.ac.uk>, ajt@rri.sari.ac.uk (Tony Tr
avis) writes:
> In article <92129225625.MIN-LVLBa00330.bionet-news@uk.ac.daresbury> you wrote:
> : I am a "virgin" bionet user, this is my first message.
> 
> Hello, David + welcome to bionet.plants!
> 
> : Is there anybody out there who is interested in how plants deal with
> : heavy metals (ie Cd, Cu, Zn etc....yes O.K you know what a heavy metal
> : is). Perhaps were could have a meaningful dialogue?
> 
> <some deletions...>
>
--MORE--(54%)

> Ok, everybody - are you interested in discussing heavy metals??
> 

I'd be interested in such a discussion; my current interest would be
taxonomic in nature.  'Fraid I can't make any contribution to such a
discussion at this time, for convoluted reasons, best alluded to by my 
post, "Request: Recruiting/Luring Biologists to the Nets", in sci.bio 
and bionet.general.  That same post would also serve as a belated way 
to introduce myself (I did not do so at the inception of this group, 
for reasons I will style as virginal shyness).

        D.R.
---------------------------------------------------------------------------
David Roller  |    Bitnet = dr@auducvax            |  "Because we're all
Auburn Univ.  |  Internet = dr@ducvax.auburn.edu   |   in this together."
---------------------------------------------------------------------------

--------




Regarding hyperaccumulators, bioremediation, etc.:

See this article:

HARROWSMITH, The Magazine of Country Life
December, 1988
Number 18
Pages 38-47

"The New Alchemist" John Todd: Transforming Waste With a Rare Mettle
By Donella Meadows

-------------------------