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Old 19-04-2003, 03:32 AM
Lambert
 
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Default Bromeliads - Pineapples

Hey guys,

I'm a college student and I'm trying to dig up information about the
evolutionary advantage of bromelain in pineapples. Could anyone give me a
few pointers or lead me in the right direction?

Thanks!



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Old 19-04-2003, 01:56 PM
Beverly Erlebacher
 
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Default Bromeliads - Pineapples

In article ,
Lambert wrote:

I'm a college student and I'm trying to dig up information about the
evolutionary advantage of bromelain in pineapples. Could anyone give me a
few pointers or lead me in the right direction?


Do an experiment. Buy a whole fresh pineapple. Peel and eat. Reflect
that domestic pineapples have been highly selected for palatability.

Note that cooked (e.g. canned) pineapple does not have the same effect.

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Old 19-04-2003, 02:56 PM
Lambert
 
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Default Bromeliads - Pineapples

I know about the effects of bromelin on polypeptide chains and how it
hydrolizes proteins. Also, the canning process denatures the enzymes via
heat. Hence you don't get the tingling sensation on your tongue (the
pineapple is actually catalysing proteins on your tongue.)

I'm just wondering about why the pineapple and other fruits (papayas,
pawpaws) have evolved to have bromelin enzymes. What exactly is the
particular survival advantage of having such a trait?

"Beverly Erlebacher" wrote in message
. ..
In article ,
Lambert wrote:

I'm a college student and I'm trying to dig up information about the
evolutionary advantage of bromelain in pineapples. Could anyone give me a
few pointers or lead me in the right direction?


Do an experiment. Buy a whole fresh pineapple. Peel and eat. Reflect
that domestic pineapples have been highly selected for palatability.

Note that cooked (e.g. canned) pineapple does not have the same effect.



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Old 19-04-2003, 09:56 PM
P van Rijckevorsel
 
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Default Bromeliads - Pineapples

Lambert schreef
I know about the effects of bromelin on polypeptide chains and how it

hydrolizes proteins. Also, the canning process denatures the enzymes via
heat. Hence you don't get the tingling sensation on your tongue (the
pineapple is actually catalysing proteins on your tongue.)

I'm just wondering about why the pineapple and other fruits (papayas,

pawpaws) have evolved to have bromelin enzymes. What exactly is the
particular survival advantage of having such a trait?

+ + +

One of the avenues to explore is the direct one:
these enzymes are in the fruits
the fruits are eaten, and hopefully the seeds are spread
the plants that has the fruits that are preferred by those animals that
spread the fruits the furthest or to the most suitable locations will
survive best
etc

Another is the systematic approach
in what plant groups do these enzyms occur?
do these plant groups have similar enzyms used for something else?
etc
PvR





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Old 20-04-2003, 04:20 AM
Lambert
 
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Default Bromeliads - Pineapples

I've done some rough research and all I can come up with is that the enzyme
may have something to do with the plant's method to acquire nutrients. The
crown at the top of the pineapple collects decomposing material and absorbs
nutrients this way.

I thought about the enzymes being appealing for eating etc. but Bromelin
hydrolizes proteins and would be generally uncomfortable for an animal to
eat (speculation)? Certainly when humans eat pineapples their tongues can
feel itchy/raw/red etc...


"P van Rijckevorsel" wrote in message
.. .
Lambert schreef
I know about the effects of bromelin on polypeptide chains and how it

hydrolizes proteins. Also, the canning process denatures the enzymes via
heat. Hence you don't get the tingling sensation on your tongue (the
pineapple is actually catalysing proteins on your tongue.)

I'm just wondering about why the pineapple and other fruits (papayas,

pawpaws) have evolved to have bromelin enzymes. What exactly is the
particular survival advantage of having such a trait?

+ + +

One of the avenues to explore is the direct one:
these enzymes are in the fruits
the fruits are eaten, and hopefully the seeds are spread
the plants that has the fruits that are preferred by those animals that
spread the fruits the furthest or to the most suitable locations will
survive best
etc

Another is the systematic approach
in what plant groups do these enzyms occur?
do these plant groups have similar enzyms used for something else?
etc
PvR









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Old 20-04-2003, 04:20 PM
P van Rijckevorsel
 
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Default Bromeliads - Pineapples

This is assuming that a diet consists of pineaple only
PvR

Lambert schreef
I've done some rough research and all I can come up with is that the

enzyme may have something to do with the plant's method to acquire
nutrients. The crown at the top of the pineapple collects decomposing
material and absorbs nutrients this way.

I thought about the enzymes being appealing for eating etc. but Bromelin

hydrolizes proteins and would be generally uncomfortable for an animal to
eat (speculation)? Certainly when humans eat pineapples their tongues can
feel itchy/raw/red etc...

+ + +


"P van Rijckevorsel" wrote
One of the avenues to explore is the direct one:

these enzymes are in the fruits
the fruits are eaten, and hopefully the seeds are spread
the plants that has the fruits that are preferred by those animals that
spread the fruits the furthest or to the most suitable locations will
survive best
etc

Another is the systematic approach

in what plant groups do these enzyms occur?
do these plant groups have similar enzyms used for something else?
etc
PvR
....
Lambert schreef
I know about the effects of bromelin on polypeptide chains and how it

hydrolizes proteins. Also, the canning process denatures the enzymes via
heat. Hence you don't get the tingling sensation on your tongue (the
pineapple is actually catalysing proteins on your tongue.)

I'm just wondering about why the pineapple and other fruits (papayas,

pawpaws) have evolved to have bromelin enzymes. What exactly is the
particular survival advantage of having such a trait?











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Old 22-04-2003, 12:20 AM
Jeff Shimonski
 
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Default Bromeliads - Pineapples

Perhaps the "purpose" is insecticidal. Ananas comosus wasn't always seedless
and the enzyme might have functioned as a toxin or repellant to insect larvae that
could have damaged the fruit before the seeds could be dispersed.


"Sean Houtman" wrote in message ...
From: "P van Rijckevorsel"

I'm just wondering about why the pineapple and other fruits (papayas,

pawpaws) have evolved to have bromelin enzymes. What exactly is the
particular survival advantage of having such a trait?

+ + +

One of the avenues to explore is the direct one:
these enzymes are in the fruits
the fruits are eaten, and hopefully the seeds are spread
the plants that has the fruits that are preferred by those animals that
spread the fruits the furthest or to the most suitable locations will
survive best
etc

Another is the systematic approach
in what plant groups do these enzyms occur?
do these plant groups have similar enzyms used for something else?
etc


I think the question sounds like, "why would a plant develop an enzyme that
digests a potential seed distributor?" Maybe the seeds are distributed by a
some organism with a salivary component that neutralizes the bromelin, and this
is a way to get specificity for a distributor.

Sean



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Old 23-04-2003, 10:44 AM
P van Rijckevorsel
 
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Default Bromeliads - Pineapples

Lambert schreef
I've done some rough research and all I can come up with is that the

enzyme may have something to do with the plant's method to acquire
nutrients. The crown at the top of the pineapple collects decomposing
material and absorbs nutrients this way.

I thought about the enzymes being appealing for eating etc. but Bromelin

hydrolizes proteins and would be generally uncomfortable for an animal to
eat (speculation)? Certainly when humans eat pineapples their tongues can
feel itchy/raw/red etc...

+ + +
A key question is the concentration of such enzymes in the fruits of
the wild progenitors. The present properties of pineapples have been set by
selection in cultivation.
PvR









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Old 24-04-2003, 04:56 PM
Lambert
 
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Default Bromeliads - Pineapples

Also does anyone happen to know the evolutionary history of the pineapple?


"Lambert" wrote in message
u...
Hey guys,

I'm a college student and I'm trying to dig up information about the
evolutionary advantage of bromelain in pineapples. Could anyone give me a
few pointers or lead me in the right direction?

Thanks!




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Old 24-04-2003, 07:08 PM
P van Rijckevorsel
 
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Default Bromeliads - Pineapples

Lambert schreef
Also does anyone happen to know the evolutionary history of the pineapple?


----- Original Message -----
From: P van Rijckevorsel
Sent: Wednesday, April 23, 2003 10:37 AM

+ + +
A key question is the concentration of such enzymes in the fruits of

the wild progenitors. The present properties of pineapples have been set
by selection in cultivation.
PvR


Addendum: the pineapple likely is a hybrid
PvR




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Old 25-04-2003, 12:08 AM
Cereoid-XXXXX
 
Posts: n/a
Default Bromeliads - Pineapples

You sound like a horticulturist when you dismiss a plant as being a hybrid.
They always confuse cultivars with hybrids.

If Ananas comosus is a hybrid, what are the parent species?

There are more than one species in the genus Ananas, so you have a few to
choose from!




P van Rijckevorsel wrote in message
.. .
Lambert schreef
Also does anyone happen to know the evolutionary history of the

pineapple?

----- Original Message -----
From: P van Rijckevorsel
Sent: Wednesday, April 23, 2003 10:37 AM

+ + +
A key question is the concentration of such enzymes in the fruits of

the wild progenitors. The present properties of pineapples have been set
by selection in cultivation.
PvR


Addendum: the pineapple likely is a hybrid
PvR








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