Re: Hormesis - Theory and Observation

["Bjorn Cedervall" <bcradsafers@hotmail.com>]

>The same dose increased the number of emerged plants in the
>field for the inbred 2416 by 23.6 %. No differences were found between
>inbreds irradiated with gamma rays at doses ranging from 80 to 700 Gy 
> >during germination assays. However, stimulatory effect in plant 
> >emergence by 36 % was observed in the inbred 3162 irradiated with 80 Gy. 
>Pants from achenes
>irradiated with 2 and 5 Gy growing in the greenhouse were taller and 
> >showed early flowering at least of 5 days. Finally, despite that the 
> >stimulatory effect was observed during germination, field and >greenhouse 
>evaluations, was not possible repeat this experiment since >the same 
>sunflower achenes were not available. Remaining question is >if this 
>phenomenon induces DNA damage and mutations, and in subsequent >generations 
>the same stimulatory effect is observed.
---
As a provocative speculation, I suggest that this phenomenon may be due to 
an induction of stress proteins that respond to many different types of 
stress - of which DNA damage could be one involved. The growth induction 
itself would then not reflect better "health" of the seed but rather "the 
environment is now so tough that you have better produce a plant and 
reproduce while you have the chance (regardless of any induced mutations)". 
The strategies for growth and producing seeds of flowering plants are very 
different depending on the general stress and "danger" in the environment. I 
could develop this more but would then drift off-topic. I would not expect 
the phenomen to show up in the next generations as well.

As a control experiment, I would try other types of stress, like enhanced 
temperatures at various levels.

Bjorn Cedervall   bcradsafers@hotmail.com

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