Sorry for the confusion. I miswrote. I meant Phytagel not PhytoAgar.
That was a brain short circuit!
Grant R. Cramer
Professor
Department of Biochemistry and Molecular Biology, MS 200
University of Nevada, Reno
Reno, NV 89557
(775) 784-4204
cramer from unr.eduhttp://www.ag.unr.edu/cramer/
On Feb 13, 2008, at 6:29 AM, Tobias Baskin wrote:
> Greetings,
> In replies to this thread, Grant Cramer mentions
> "PhytoAgar" and Brian Forde mentions "PhytagelTM" which I think is
> the same phytagel we used awhile back too. But is PhytoAgar the
> same stuff as Phytagel? or are they different? Do you know?
>> Thanks,
> Tobias
>> At 4:40 PM -0800 2/12/08, Grant Cramer wrote:
>> I have found very negative effects on root growth using BactoAgar
>> both from batches in the United States and Australia. I have NEVER
>> had a problem with PhytoAgar on root growth in root length assays
>> up to a week. After that they are in the dish for too long and
>> will suffer. One can supplement with sucrose in a standard quarter
>> strength Hoaglands solution without problem. I agree you should
>> not use MS medium or you will suffer from osmotic stress and
>> perhaps other things that are out of balance for roots. The roots
>> will grow without the sucrose but slower. It depends on your
>> experiment, but those shaded cotyledons in a plastic petri dish
>> can only do so much in the dark or dim light. I always grow them
>> in the dark, as light inhibits root growth.
>> Grant R. Cramer
>> Professor
>> Department of Biochemistry and Molecular Biology, MS 200
>> University of Nevada, Reno
>> Reno, NV 89557
>> (775) 784-4204
>>cramer from unr.edu>>http://www.ag.unr.edu/cramer/>>>>>>>> On Feb 11, 2008, at 6:33 AM, Tobias Baskin wrote:
>>>>> Dear Tanya,
>>> Some years ago, we investigated a variety of different
>>> agars (some of which you mention). We found reproducible
>>> differences in root elongation rate but perhaps on the order of
>>> 10 to 20 %. Clearly the roots liked some agar better than others.
>>> We also found a little bit later when using phytagel that root
>>> elongation rate depended on the temperature the molten mix was
>>> held at before pouring, or might have simply been quite
>>> irreproducible. But again I am talking about differences on the
>>> order of 20%. Big enough to readily measure but not monstrous. On
>>> no agar did we see the kind of developmental change you are
>>> mentioning. On some conditions I have seen (and read) that
>>> severely salt stressed or water deficit stressed roots will swell
>>> so I'd guess what you are describing goes way beyond what can be
>>> expected from different brands/formulations of agar.
>>>>>> Hope this helps,
>>> Tobias
>>>>>> At 3:10 PM -0600 2/9/08, Falbel, Tanya G. wrote:
>>>> Colleagues:
>>>>>>>> Over the years, I've used several brands of agar for growing
>>>> Arabidopsis seedlings on MS medium,
>>>> from Gibco, Sigma, and others. I've heard that some groups use
>>>> Noble agar,
>>>> others, bacto-agar, others in the past have washed their own
>>>> agar, used phytagel or other
>>>> gelling agents. I have two questions:
>>>>>>>> 1) What brands of agar are most commonly in use now by groups?
>>>> I've found something similar
>>>> to Gibco's Phytagar that is now available through Caisson labs.
>>>> Other groups seem to like Sigma's
>>>> A1296. But besides those, what do most groups use? I'm
>>>> especially interested in the opinion of
>>>> groups that measure root length or root branching - growing
>>>> roots vertically on plates
>>>> for more than just a couple of days. (as opposed to just
>>>> antibiotic selection)
>>>>>>>> 2) Does anyone know what inhibitors are washed away? Are
>>>> micronutrient ions or other toxic
>>>> compounds bound to the crude agar? Has anyone looked into this?
>>>> This may have been a question
>>>> that came up among researchers 10 years ago, but I couldn't find
>>>> any record in the archives.
>>>>>>>> Here's why I'm asking. I made up a batch of medium with a brand
>>>> of 'purified agar for microbial use',
>>>> and got a very strong inhibition of root meristems. Seed
>>>> germination was good, but roots failed to elongate
>>>> any further after about 4 days of growth. The root meristems
>>>> became a swollen mess, reminiscent of what
>>>> happens in weak gnom alleles. I'm trying to decide if this is
>>>> something worth looking into.
>>>>>>>> I know that for regeneration of plants in tissue culture, folks
>>>> are very fussy about particular brands of agar.
>>>>>>>> Please let me know what brands you have used with success or
>>>> failure.
>>>> I'd be especially interested in other similar experiences -
>>>> where a brand
>>>> wreaked havoc on root meristems.
>>>>>>>> Thanks
>>>>>>>> Tanya Falbel
>>>> Department of Biology
>>>> 105 Garfield Avenue
>>>> University of Wisconsin-Eau Claire
>>>> Eau Claire, WI 54702-4004, USA
>>>>>>>> Tel: 715-836-5087
>>>> Fax: 715-836-5089
>>>>>>>>>>>> _______________________________________________
>>>> Arab-gen mailing list
>>>>Arab-gen from net.bio.net>>>>http://www.bio.net/biomail/listinfo/arab-gen>>>>>>>>> --
>>> _ ____ __ ____ / \ / /
>>> \ / \ \ Tobias I. Baskin
>>> / / / / \ \ \ Biology Department
>>> /_ / __ /__ \ \ \__ 611 N. Pleasant St.
>>> / / / \ \ \ University of
>>> Massachusetts
>>> / / / \ \ \ Amherst, MA,
>>> 01003
>>> / / ___ / \ \__/ \ ____
>>>http://www.bio.umass.edu/biology/baskin/>>> Voice: 413 - 545 - 1533 Fax: 413 - 545 - 3243
>>>>>> _______________________________________________
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