Kurinji (Strobilanthes) and the quest for Plant Intelligence

Filed in Uncategorized, December 31, 2006, 1:06 am by

Updated Jan 8, 2007: Selva, The Scientific Indian at Science Blogs linked to this post. Thanks a lot Selva Updated Jan 5, 2007: April Holladay of Wonderquest is featuring science related posts from this site on her site. This post on Plant Intelligence is currently featured. Thanks April for your generosity.
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2006 is the year of the Kurinji (Strobilanthes Kunthiana), the plant that flowers every 12 years! I had a chance to see the Kurinji blossom this year in Kodaikanal. The question arose in my mind, why 12 years? I wanted to write what i found before the end of the year. [Above picture from The Hindu newspaper]
Why does this phenomenon happen?

First, the simple answers:
1. Kurinji practices an evolutionary strategy known as predator satiation – If a lot of plants flower at the same time, it will be difficult for predators to obliterate all of them.

2. It appears the plants wait for a period of time to flower untill they have enough nutrients to
support seeding. In Kurinji’s case that time period happens to be 12 years.

I was not satisfied with this set of answers (paraphrased from Senthil Subramanian, see references below).

How do plants keep track of time and how do they know when to flower? The first part of the question is simply answered by saying plants have a mechanism to keep track of time and that is how they know. The second part turns out to be a lot tougher question to answer.

It turns out Scientists have been grappling with this question for a long time. In 1937, a Russian scientist hypothesized that there is a plant hormone called Florigen that is responsible for flowering. Scientists have been looking for it since then and it appears they may have found it. Hold on to this, we will come back to this.

We first need to understand some more about the plant clock. It appears that there are 2 aspects that the plant needs to keep track of – one is the day length and the other is the ability to remember the length of winter (cold temperatures) so that they can flower at the appropriate time in Spring. The day length is likely to be a simple counter whereas the length of winter is some type of cellular memory.

Scientists have isolated the day length counter gene called ELF4. Remembering the winter or simply duration of cold temperatures is a process known as Vernalization. By studying Vernalization, Scientists have identified the mechanisms that control vernalization and in the process explain how plants remember winter.

Coming back to Florigen, Scientists have found a mechanism in plants known as the CO/FT module (Constans is CO, Flowering Locus T is FT) that seems to be the elusive Florigen. It turns out that CO protein keeps getting accumulated and when it reaches a threshold level, it induces the transcription of the gene FT in the leaf and the FT mRna (messenger RNA) moves from leaf to shoot apex where flowering is triggered by the FT protein.

Coming back to Kurinji, this CO is getting accumulated over a 12 year period calculated by the clock gene and flowering starts. In Kurinji, another interesting thing happens, the plant dies immediately upon flowering. Scientists are working on isolating what they are calling as the death signal which gets generated containing the instructions for the plant to die. But why 12 years?

Could not come up with a clear cut answer to this. I have one potential explanation – that in the plant kingdom’s evolution from annuals to perennials, the 12 year plant is a pit stop!

During my research, i came across several amazing facts about plants –

a. Did you know that plants used Aspirin (Acetyl Salicylic Acid) in their rudiementary defense system?

b. Dodder plant uses its sense of smell.

And finally my quest was complete when i came across Tony Trewavas’s brilliant paper “Aspects of Plant Intelligence“. In fact, Trewavas uses Dodders as an example of plant intelligence. He didn’t know about its sense of smell when he wrote this paper. This is a must-read paper for people interested in knowing more about plants.

Notes & References:
1. Senthil Subramanian, Donald Danforth Plant Science Center, St. Louis, U.S.comes up with some great answers to explain Kurinji’s gregarious flowering.

2. Kurinji is not the only rare blooming plant. Our friend Morgen Jahnke at ITOTD has some more – The Titan Arum lily, the talipot palm..

3. How plants remember winter – Sibum Sung and Richard M Amasion explain how Vernalization works in this important paper.

4. How do plants keep time – A Science Daily report mentioning the discovery of the ELF4 gene that seems to be responsible.

5. The landmark paper that talks about the CO/FT module.

6. Arabidopsis Thaliana seems to be the plant kingdom equivalent of the fruit fly Drosophila Melanogaster.

FTOTW ending Dec 23 (#12) – Kitty Genovese Syndrome, Shakespeare’s impact on the brain..

Filed in General Interest, December 26, 2006, 9:51 am by , ,

1. Our friend Joe Kissell of ITOTD talks about the Kitty Genovese Syndrome – an interesting phenomenon where bystanders just watch and don’t do anything to prevent the crime that is happening in front of them! 2. In an insightful piece of research, Scientists report that Shakespeare used words in such a way as to cause heightened brain activity. Now you know why Shakespeare is mighty popular! 3. After Humpback Whales it is the turn of Gibbons to display grammar skills. Researchers have found that the Gibbons use the same notes for their calls but arrange the notes differently depending on the situation. 4. Why are Blockbusters called so? The Wikipedia has some interesting explanations. <Via Priya Raju> 5. I had written about the movie North Country. Priya Raju had not seen it. So we saw it over the weekend. She liked it a lot as well. If you haven’t seen it yet, get it. 6. On Saturday got the opportunity to attend an innovative concept in Carnatic Music, a vocalist singing with the Piano as an accompaniment. The vocalist being the up and coming star Sikkil C. Gurucharan and the Pianist Anil Srinivasan. It was extremely good. In case i don’t write this week again, Happy and Prosperous new year to you and your families.

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Me, Myself & My Blattiphobia

Filed in Uncategorized, , 9:06 am by ,

Priya Raju digs deep into her fear of cockroaches and comes up with some surprising possibilities. As for me, I am not afraid of cockroaches but I am afraid of creepy-crawly insects like spiders.
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I’m terrified of roaches. I can’t see even a single grown roach or its picture, without freaking out. And I have plenty of company. Blattiphobia – the paralyzing fear of roaches – is something that millions of us suffer thru.
It seems ridiculous to me that any human being would be afraid of something as insignificant as a roach: most specimens are just 2 inches long. They are neither poisonous nor are they terrifying. Surely, I must be able to explain why I’m afraid of roaches. After all, everything has a reason.

It is true that roaches bite – they’ll even eat human skin. In fact, it will eat any edible organic matter that doesn’t move. Since they are nocturnal, the bigger roaches may nip your ears or your scalp. But unless you are a child, your skin just isn’t tender enough to suffer damages from a roach bite.

Most people who are afraid of roaches aren’t exactly worrying about their bite. Mosquitoes bite too, but when was the last time you saw anyone screaming their head off in mortal fear of skeeters?

There is a theory that such phobias represent genuine fears that helped our ancestors at some point or another. If that is the case, the fear should be much more prevalent than it is today. Plus, I see no earthly benefits for our ancestors: If a fear of pythons has been passed that way, it might be meaningful. I can hardly imagine 12 feet long, human-eating roaches ruling the terrestrial environment in the late Pleistocene.

It has been observed that a considerable segment of the people with roach phobia may also fear other creepy-crawlies such as snakes, spiders, lizards, scorpions, worms etc. So, some people argue that roach phobia is a displaced fear of these other creatures. Yes and No: I fail to see how one can mistake a roach for a snake or a scorpion. The rest: I think there’s a connection – more on that later.

It is true that scorpions have a segmented body like roaches. Well, if you want to see the resemblance, turn an obliging roach backwards to see its ugly arthropod body. When I was a child of 5, I called the adults to the foyer – with true old world hospitality – to welcome a visitor. My mom came in, with the cook in tow. My mom took one look at the “guest” & froze: ambling along the foyer was a huge scorpion. Evidently, it was pleased with the reception & was inspecting its new quarters with enthusiasm. Our cook let out a piercing howl, dropped the griddle on the scorpion in fright & sent it on a one-way trip to join its Maker.

What I’m saying is this: I have a healthy fear of scorpions, born out of respect for its sting. But that’s about it: No dread, no scanning the horizon for some sign of the oppressor, no inborn fear. So, I don’t see the connection here either.

How can anyone transfer their fear of snakes onto roaches? There is absolutely no resemblance. I read that a genus of roaches – Gromphadorhina – hiss like snakes. This hissing is loud enough to scare dogs. But, our common, garden variety roaches are mute – so, there is no mistaking a roach for a snake!

Some people argue that Fear Conditioning is the cause. This is defined as a synthetic fear that we develop on a neutral object, when we repeatedly see it while in a state of fear. I once saw a TV program of a woman scared of feathers. It was very painful to watch an otherwise normal woman, become hysterical at the sight of a single feather. People might develop it – say, for instance – if they had a cruel care-taker/guardian/parent who beat them up while wearing feather boas.

This again is far-fetched in the case of roach phobias. If something scary happened in one’s childhood, it might create a synthetic fear of something of considerable size – like a teddy bear, a cabbage patch doll or roller skates. A roach is just too small & insignificant to be noticed.

We can stop right here, shrug our shoulders & observe that phobias are irrational; so, trying to find a reason for them is futile: Or not. Perhaps if I try to explain my phobia in words, it will help. Here we go:

    Roaches are the epitome of ugliness. They have the most nauseating color combination in the entire animal kingdom – a dirty brown body with a yellow band near the neck. Their antennae are like limp hair – they have none of the cuteness of the bristly whiskers of a cat. Their legs are the stuff of nightmares – they have built-in spikes. When I was a child, a roach got into my T-shirt & waltzed all over my back, till my mom came to my rescue. My neck prickles when I think of how their legs felt on my skin.
    Their mobility is their worst trait – I can only utter primordial screams when they move in their characteristic erratic fashion. They can flatten their body like pancakes & slither into the smallest of cracks. They will almost always run in the least expected direction. And boy, can they fly.

Just read the above blurb: It doesn’t describe fear, but that’s what I set out to do. If I wanted to explain why I’m afraid of tigers – for instance – I’ll say, “becoz they might eat me, stupid”. You can’t argue with that logic.

My blurb may not describe fear – but it describes another very basic emotion: DISGUST.

But Fear and Disgust are distinctly different emotions. There are considerable differences in the neural pathways for these feelings. There are distinct facial expressions associated with both of them. The Amygdala makes us aware of our fears, while the Insula processes disgust.

One can argue that most stimuli create a mixture of emotions in us. So, could the roach trigger both fear & disgust in me? Possibly – but we still can’t get away from the fact that I haven’t used a single word in my blurb that expresses fear.

Blattiphobes show all the classic responses to disgust: Nausea, Avoidance & Sensitivity. In other words:

  • Nausea AKA Food Rejection – We are rejecting the roach as food. EWWW! Enough said.
  • Disease Avoidance – By running away, we are avoiding them like the plague. Roaches have the repulsive habit of eating & shitting in the same place. If you leave food open, just throw it in the trash. Chances are, the roach has decorated your food with its pee. Did I mention that the GI tract of roaches has all the disease-carrying germs in the neighborhood? This is because they eat anything. Their feces will have representative samples from all the germs in their gut.
  • Sensitivity AKA Contamination Prevention – We are trying to ensure that the stupid roach doesn’t get into our mouths. If that happens, we would have to vomit till we don’t have any innards.

Let’s consider this: Insula takes some time to respond. Amygdala responds almost instantaneously. This indicates that our brain needs some time to process the disgust-relevant image – unlike fear.

There is a theory that the fear of roaches is hereditary. Neither of my parents are afraid of roaches, but I have several aunts & cousins (all on my father’s side) who’ll shriek & bring the house down if they saw a roach. But statistically, there is no proof that this fear is passed on from generation to generation.

But something else is passed on: Sensitivity to Disgust. Whether it is passed on genetically or thru social conditioning – we don’t know yet. I would argue that it is a combination of both.

It is well known that roaches are carriers of disease. So, if someone has a heightened sense of disgust, they’ll try their best to avoid roaches – or, spiders, rats, worms & lizards. All of them have or had a reputation of spreaders of disease. Or, they look plainly repulsive.

It is interesting to note that most other phobias are a symptom of an anxious personality: While Heightened Disgust manifests itself as phobia of small animals.

Tail Piece

I’m offering this as corroborating evidence. My brother has a phobia for lizards. We – me, my brother & our father – also have Migraines, Motion Sickness & Vertigo. In short, ailments which make us very nauseous – perhaps this proves that we have a tendency to be disgusted: Since nausea is an essential element of disgust.

I read that Migraine sufferers have low levels of Serotonin. Lowered levels of this neurotransmitter result in obsessive or compulsive behavior. My father is painfully methodical in everything. My brother is compulsively clean. I obsess about every little detail in anything I do. In short, none of us are easily satisfied. Classic symptom of low Serotonin, I think.

So, here is what I wonder. Do people with low serotonin levels have phobias of creepy-crawlies? Will my Blattiphobia be cured temporarily if I get a Serotonin injection? It would certainly be interesting to try it out.
References:

  1. http://www.bio.umass.edu/biology/kunkel/cockroach_faq.html
  2. http://www.open2.net/healthliving/body_mind/fear_and_loathing_p.html
  3. http://mentalhealth.about.com/library/sci/0203/bleww203.htm
  4. http://www.psyeta.org/sa/sa2.1/davey.html

Ann Druyan starts blogging

Filed in Uncategorized, December 22, 2006, 6:26 am by

If you are wondering who that is – here is a snippet from her bio –

Ms. Druyan was married for nearly two decades to her long time
collaborator, astronomer Carl Sagan, until his death in December 1996.
Their children are Alexandra, born in 1982 and Sam, born in 1991.

I am a big fan of Carl Sagan and have been one since I was a child hooked onto Science through his unforgettable Cosmos series.  Ann Druyan has worked on many projects with Carl Sagan including Contact (one of my all-time favorite great movies). Ann Druyan entered the blogosphere on Dec 20th, on the 10th anniversary of his death, with a gripping, sentimental post about Carl Sagan.  If you ever had a wish to read Carl Sagan’s blog, this is the closest it gets. Welcome aboard Ann.  Thank you for  starting a blog on behalf of the zillion fans of Carl Sagan around the world. We are sure you will make the science blogosphere a better place. P.S. It appears Nick Sagan has been blogging almost for a year now.  

Dr. Aubrey Daniels’s ABC Theory seems to be mimicing how the brain works!

Filed in Uncategorized, December 20, 2006, 12:52 am by ,

Updated Dec 17, 2006 – added some more details.
Updated Dec 20, 2006 – I had requested April Holladay, a science columnist for USA Today, whose opinion I respect a lot,  to review this post.  Here is what she had to say about this post:
“An outstanding blog (and the one before on the same subject)!  I agree wholeheartedly with your brain analysis and the ABC author’s (Daniel) behavior analysis.  It makes sense.  I also agree with your caveats.  You do good work.”.  Thanks a lot April. I am honored.

I also received some comments from Archana Raghuram (please see the comments section). Based on that I realized something and I decided to move the disclaimer to the top of this post:

Note of caution – Neurology is extremely complex and still not completely understood even by scientists, so please do not take what i am about to say as gospel truth. Having said that, what i am about to say is the most likely way in which the brain is operating per currently published information.

The main purpose of this post is to show that the brain conditions our behavior by using a PIC consequence closely resembling Dr. Daniels’s theory. This post is not intended to be an overarching theory of how the brain works.

I have written about Dr. Aubrey Daniels’s ABC Theory of Behavior (Antecedents, Behaviors, Consequences) in the past. I have been completely taken in by this theory because it seems to offer the best escape route from change management problems that are typical for large organizations. My belief in this theory has been further emboldened through my experience applying it.

As you all know Change Management is the biggest hurdle any Knowledge Management practitioner faces. KM applications are fundamentaly different from routine business applications because of the fact that using KM applications and contributing to KM is typically optional. Therefore, to state the obvious, getting people into the culture of participating in KM is a big Change Management challenge.

We have now applied Dr. Daniels’s ABC Theory in a variety of ways in our KM program and I should say I have been surprised by the dramatic results. IMHO, a theory of this kind has a better chance of adoption if it can be explained using some more rigorous scientific fundamentals. As you know, off late, I have been studying the neuroscience of change management (you may have seen my post on the neuroscience of Not Invented Here syndrome). Today morning, i was reading about Neurotransmitters and suddenly a light bulb went off in my head as a connection between the ABC theory and the operational mechanics of the brain occurred to me. How does the brain makes us do things that are important to us? The simple answer is that it uses neurotransmitters.

What happens is when our brain wants us to do something it uses a neurotransmitter called dopamine. When you see something you like – a good looking person you would like to have sex with or a delicious item of food or chocoloates or ice creams or any of those, dopamine is secreted to make you “want” to have sex or eat. This is the starting point of behavior because without the “want” you are not going to do anything. As dopamine surges you go ahead and do the action (hopefully you are careful when it comes to a “want” of the sex kind :-)). Now what happens is the brain rewards you with another neurotransmitter called Endorphin.

Endorphins are also called “feel good” molecules and they give you the sense of elation or happiness that you experience after you have had great sex or after eating great food. Now once the rewards have been given, the desire increases further with some more dopamine being secreted which makes you repeat the same activity again to experience the neurological reward. [Added next 2 sentences]. It is also possible that endorphins alone are a reward enough for you to repeat the activity and Dopamine is no longer needed after you have performed the action. In other words, Dopamine influences you to do something and once you experience the endorphin reward you will do the activity again even if you don’t receive another ration of dopamine to infuence you again. This is the cycle of human behavior – dopamine, action, endorphin and you can see how closely it resembles the ABC Theory of antecedents, behaviors, consequences. Dopamine creates the antecedents, behavior follows and endorphins are the consequences. Now i started wondering how does this loop get broken because it seems like an infinite loop that we cannot get out of. That is where the third neurotransmitter Serotonin enters the picture. Serotonin is secreted when you are satiated. Without this feeling of satiation you will not be able to leave the dopamine-action-endorphin loop. Dr. Daniels says that changes in behavior are easier to accomplish if the consequences are Positive Immediate and Certain (PIC) and more difficult to accomplish if the consequences are Positive Future Uncertain (PFU). If you think about what the brain does, it is exactly doing what Dr. Daniels is prescribing – give PIC rewards, namely, an endorphin rush. The brain does not wait till the end of the year to release endorphins. Therefore, this need for PIC rewards seem to be hardcoded in the brain. In sum, i am now more convinced that Change Management programs that leverage  Dr. Daniels’s theory are likely to succeed. Hope you are convinced as well.

Notes & References:
1. Dopamine, Endorphin and Serotonin are very important neurotransmitters and they help explain a lot of human mental ailments like depression, attention deficit disorder, addiction etc.

 2. The chemistry of desire in the Time magazine  discusses the role of dopamine.

 3. The chemistry world magazine discusses the Chemistry of Love including the role of Serotonin.

4. The Biology of Joy – a discussion that includes the role of endorphins in pleasure.

5. The Wikipedia – links provided inline above.