questions about gibberellins

[Nancy Harrison]

In article <32913D0A.906 at worldnet.att.net>, hortus at worldnet.att.net says...
>
>MMPHILLIPS at ALEX.STKATE.EDU wrote:
>> 
>> I'm in the midst of teaching about plant hormones in my botany class
>> and they have again stumped me with a question about the finer details of
>> the current topic.  (And since I'm a plant ecologist only superficially
>> trained in plant physiology and biochemistry, I am stumped more often
>> than I'd like).  The latest question is:
>> 
>>         Why do normal or wild-type plants generally NOT respond to
>>         exogenous applications of gibberellins??  especially given the
>>         fact that this hormone was discovered because of the effect of
>>         fungal gibberellin on rice seedlings.  What's the difference
>>         between gibberellin due to fungal infection and that applied by
>>         a human investigator?  Or were the rice varieties affected dwarf
>>         varieties?
>> 
>> I'd appreciate any light you can shed on the finer points of the action
>> of gibberellins.
>> 

In our Gibberellin expt, we use 1 microgram/ml of GA, and this concentration
has an effect on normal peas as well as dwarf. This is a very simple
expt that is designed to show dwarf plants overcoming their dwarfism
rather than any other great truths about GA.
-- 
---Nancy Harrison, SRJC Life Sciences, Santa Rosa CA 95401
   http://www.sonic.net/~vulpia/index.html (with link to CNPS in Sonoma 
County)