John,
I suspect that arabidopsis roots in the 'wild' might get more
light than many others insofar as they grow in disturbed open areas,
though of course not as much light as in a growth chamber. Roots of
many species stop elongation or nearly so when exposed to light.
At least plants are often sucrose limited. I can see no
analgous argument for vitamins and I agree tha the addition of
vitamins is probably an appendix, as it were. The sucrose in the
medium perhaps acts like some extra photosynthate, feeding the root.
In our hands, for plants on plates, the addition of 1% sucrose makes
root elongation more uniform among a set of plants on a plate, which
is certainly convenient.
As ever,
Tobias
At 7:50 PM +0100 5/29/12, John Turner (BIO) wrote:
>Dear Tobias
>>Our experience confirms your comment that MS salts at full strength
>suppress growth of Arabidopsis in axenic culture, and we use
>half-strength, as you suggest. We don't use vitamins. Likewise there
>should be no need for sucrose for growing green plants. But we use
>1%.
>>The MS medium was originally for culture of non-photosynthetic cells
>and tissues, and has been adopted possibly without extensive testing
>for Arabidopsis. Growing Arabidopsis in agarose has other
>undesirable effects. Light induces proplastid development in roots
>(which are normally kept dark in soil) and this may reduce growth.
>Many years ago this group posted that Arabidopsis grows better when
>its roots are in medium which promotes drainage, so soggy agarose
>may not help.
>>On a quiet road near where I live there is a 10 metre row of robust
>Arabidopsis plants, now in full seed, growing out of a 1/8 inch
>crack between the kerb and paving stones....
>>John
>>>John Turner
>Professor of Plant Science
>University of East Anglia
>Norwich Research Park
>NR4 7TJ, England
>>email: j.g.turner from uea.ac.uk>Phone 0 1603 592192
>>>-----Original Message-----
>>From: arab-gen-bounces from oat.bio.indiana.edu [mailto:arab-gen-
>>bounces from oat.bio.indiana.edu] On Behalf Of Tobias Baskin
>>Sent: Tuesday, May 29, 2012 2:18 AM
>>To: Pablo JENIK; arab-gen from magpie.bio.indiana.edu>>Subject: Re: [Arabidopsis] Yellowing seedlings on MS
>>>>Hi Pablo,
>> In my experience, full strength MS should be considered a
>>stress. I suggest trying half strength. I realize that probably you
>>have been growing your plants on 1 x MS for "years" with no problem
>>but if something now is causing some other stress, then the two of
>>them together could be synergizing.
>> And on this subject, when I was first getting into growing
>>arabidopsis, we tried + vs - vitamins and in our conditions found
>>absolutely no effect of the vitamins. So we leave them out. It has
>>always puzzled me what they are supposed to be doing. Are they really
>>taken up? Don't plants make enough of their own? (But I don't think
>>the vitamins could be hurting your seedlings, just making a comment).
>> As ever
>> Tobias
>>>>At 10:09 AM -0400 5/28/12, Pablo JENIK wrote:
>>>Dear Colleagues,
>>>>>>I'm looking for clues in solving a growing problem (no pun intended).
>>>When we grow our Arabidopsis (a variety of genotypes) on standard MS
>>>plates (1x MS, 1% sucrose, 1x Gamborg's vitamins), the seedlings look
>>>yellow-green instead of bright green, and the cots seem to curve down.
>>>Seedlings growing on soil side-by-side with those growing on the
>>>plates (same growth chamber, same lights) look fine. Any ideas about
>>>what may be going on and how to solve it?
>>>>>>Thank you very much,
>>>>>>Pablo
>>>>>>--
>>>Pablo Jenik
>>>Assistant Professor
>>>Department of Biology
>>>Franklin and Marshall College
>>>P.O. Box 3003
>>>Lancaster, PA 17604-3003
>>>(717) 358-4431
>>>>>>_______________________________________________
>>>Arab-gen mailing list
>>>Arab-gen from net.bio.net>>>http://www.bio.net/biomail/listinfo/arab-gen>>>>>>--
>> _ ____ __ ____
> > / \ / / \ / \ \ Tobias I. Baskin
>> / / / / \ \ \ Professor
>> /_ / __ /__ \ \ \__ Biology Department
>> / / / \ \ \ 611 N. Pleasant St.
>> / / / \ \ \ University of
>>Massachusetts
>>/ / ___ / \ \__/ \ ____ Amherst, MA, 01003
>>www.bio.umass.edu/biology/baskin
>>Voice: 413 - 545 - 1533 Fax: 413 - 545 - 3243
>>>>_______________________________________________
>>Arab-gen mailing list
>>Arab-gen from net.bio.net>>http://www.bio.net/biomail/listinfo/arab-gen
--
_ ____ __ ____
/ \ / / \ / \ \ Tobias I. Baskin
/ / / / \ \ \ Professor
/_ / __ /__ \ \ \__ Biology Department
/ / / \ \ \ 611 N. Pleasant St.
/ / / \ \ \ University of
Massachusetts
/ / ___ / \ \__/ \ ____ Amherst, MA, 01003
www.bio.umass.edu/biology/baskin
Voice: 413 - 545 - 1533 Fax: 413 - 545 - 3243
