Re: Epigenome genetics

Yes, that is one hypothesis and of course how long tha actually would take to accomplish a resetting of the epigenome.

Of course for experimental purposes seed would have to be collected from various crosses (proven reblooming types, and non-rebloom types and prob some controlled species crosses), and from climates over multiple years and observed simply because we have no real idea of what the weather will be like after the flowers have been pollinated or what the real epigenome is originally set at if it wasn't reset... if it could be.  Lots and lots of effort, time and space but might be worth it down the road.  Might be more of a chicken and egg situation.



-----Original Message-----
>From: christian foster <flatnflashy@yahoo.com>
>Sent: Sep 1, 2008 12:25 PM
>To: iris@hort.net
>Subject: Re: [iris] Epigenome genetics
>
>Paul,
> 
>It seems like there might be data RE: the question of the reset
>epigenome.... but I suspect only the most stalwart readers would have
>understood what data you need from you post.
> 
>If I'm understanding you
>correctly, your hypothesis is that the seeds/seedlings resulting from a bloom
>on a plant that is "well established" might be better able to survive/rebloom
>in a "new" climate because the epigenome would have had time to reset.  So,
>then, the data you need is comparisons between the seedlings from first bloom
>seasons and the seedlings resulting from following seasons.  The trouble is
>that most breeders probably do not repeat the same cross until they have had
>time to see the results of the first attempt.
> 
>Christian
>
>
>
>----- Original
>Message ----
>From: Paul Archer <pharcher@mindspring.com>
>To: iris@hort.net
>Sent: Sunday, August 31, 2008 7:40:16 PM
>Subject: [iris] Epigenome genetics
>
>I
>was watching "Nova" on PBS last night and their show "Ghost in Your Genes"
>got
>me thinking.  It does somewhat follow what we are seeing in our Iris,
>although
>all particular instances of their discussion involves animals not
>plants.  I
>will note that this information does not detract from the work we
>are doing as
>a group or by other Iris breeders.  It may simply help us
>understand what is
>going on.  Some ideas I had I will elaborate on later.
>They may be far beyond
>the scope of anything most people can fathom, but it is
>food for thought for
>those interested and indicates there might be some
>advancements made toward
>our goals.
>
>The show discussed what is called the Epigenome of DNA.  This is
>the genetic
>material outside of the actual genes. This is the DNA that
>controls when a
>gene is turned on or off in an organism.
>
>They discussed two
>issues.  The first was differences in twins and how one
>twin can develop
>cancer or autism and the other be perfectly fine the cause
>being the
>differences in their Epigenome while their genes remain identical.
>The
>differences in the Epigenome are the presence or abscence methyl groups
>attached to the DNA that turn on or off the firing mechanism of the gene
>itelf.  Some human tests subjects are receiving chemotherapy of a previously
>discounted anticancer drug that was deemed too toxic.  They are receiving it
>at much lower doses over longer time periods and it is killing (turning off
>genes in) cancer cells by removing the methyl groups attached to the DNA that
>made the cancer genes active.  This in effect makes the cells "reset"
>themselves to a more natural state of activity.  The second issue they
>discussed was that of generational inheritance.  This is the inheritance of
>information in the DNA carried from one organism to another and then to the
>grand-offspring, a genetic memory.  We inherit genes from our parents and
>grand parents but we also inherit their epigenome and how it was set at the
>time of conception.  The now documented evidence they have is that of a
>isolated group in Sweden that went through famines and overabunances and then
>tracked the deaths and illnesses of their children and grandchildren.  They
>found that even though the grandchildren didn't witness hardships or
>overabundances they still fell ill although their grandparents expressed no
>such tendencies, particularly diabetes if the grandparental overabundances
>occurred.  Similar experimental observations were made in mice with aggression
>tendencies relating to rearing habits of the mother mouse and the effects on
>her grandchildren with the grandchildren also being aggressive.
>
>Here's a link
>to the page to see excerpts
>
>http://www.pbs.org/wgbh/nova/genes/
>NOVA | Ghost
>in Your Genes | PBS
>
>So these two findings got me thinking how the epigenome
>might relate to Iris.
>You could have two (or more) plants of the same variety
>both at the same
>apparent stage of development and one bloom and the other
>not.  They  are
>genetically identical but epigentically they are different. 
>Might there
>simply be a way to coax the plants to have a similar Epigenome and
>"reset" it
>to our favor at the right time?
>
>How does this effect the seed? We
>might have assumed that the genes are
>"rejuvenated" once a seed is formed but
>now this may not be the case at all.
>Some gene are "rejuvenated" or shall we
>say in a juvenile/vegetative state and
>some are obviously probably not.  So
>what is actually carried over?
>Would it be better to wait a few years to set
>seed on a newly received plant
>until it "resets" itself (if it can)?  We have
>noticed some cultivars do take
>a few years to acclimate to a new climate and
>then they are fine.
>How would the results be different in growth/rebloom in
>one year's batch of
>seed to a batch obtained years later from the same cross?
>Might this also be a solution somewhere in there to those of us who try to
>grow rhizomes from another climate just to have them fail repeatedly either
>soon after transplanting or three years down the road just disappearing
>altogether?
>Is there some way we overcome the plant being epigenetically "set"
>by
>chemically "resetting" its Epigenome to a base state as in the cancer
>patients?
>I'm not sure if Science knows just exactly what roles gibberellic
>acid and
>abscisic acid play in plant growth and dormancy, but we do know they
>do have a
>significant part.  Might these chemicals or other plant hormones be
>the
>signals or actual culprits in DNA methylation/demethylation.  I'll bet
>they do
>play a significant part.  Could these or others chemicals be used to
>"reset"
>the Epigenomes of Iris?
>
>Here's a link to a scientific article I
>googled that might shed some light.
>It does also show some epigentic
>inheritance (not genetic as we have
>previously thought) of vernalization of
>seed from the parent.  So our Iris may
>be affected in similar ways (dry,
>stressed summers vs. cool, wet ones).  This
>may imply that a plant grown in a
>cold climate might be significantly more
>prone to produce cold climate
>rebloomers because the seed has been set that
>way, but not simply based on its
>actual genes, but it's Epigenome.  Does this
>imply that the plants need to be
>"reset" before seed is obtained for your
>climate if your goal is to have warm
>climate rebloomers (and vice versa)?
>http://www.pnas.org/content/95/10/5824.full.pdf
>5824.full.pdf (application/pdf
>Object)
>
>I'm hoping Chuck will have some comments, some scientific insight and
>research
>reports he can scrounge up about all of this.
>
>
>Paul Archer
>Indianapolis, IN  Zone5
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