Strolling through Ooty and Coonoor with a Foldscope: Gene silencing, pollen tubes and other observations

I was in the Nilgiris in August visiting Conoor and Ooty; traditional summer vacation  places for people in the South of India. The thing that catches your attention is the tremendous invasion of the landscape by species like Latana at the border of human settlements and the forest. While they make a pretty picture, they are basically impossible to remove as they rapidly grow and take over ecosystems (see previous post on Invasive species– https://microcosmos.foldscope.com/?p=8197). Yet another widespread presence is the tea plant, which has replaced the natural forest flora and while I followed my troop through the commercial landscape of Coonoor, I was a bit depressed and wondered if I could find something of interest, but there is always something. Below I list a few observations (Click on the pictures to enlarge them):

1.  In the hotel where I stayed was this rather photogenic Passion flower (also called krishnakamal), which has a three-pronged stigma, a hinged anther, androgynophores and corona filaments– very aesthetic and a very interestingly shaped ridged pollen.

2. As we were browsing through the tea gardens, I came across this Spiderwort plant (Trandescantia), very similar to the one I saw in  Pollachi a couple of years back. They always make for excellent views under the foldscope, especially due to their unsusual trichomes.

3. Of course a few tea plants were also flowering and I managed to get their pollen under the foldscope.

4. This violet Duranta erecta  (an invasive species) had two types of trichomes, one in the center of the petal and another bordering the edges. It also had a lot of moving specs that turn out to be an insect, perhaps a beetle?

5. And then there was this grass with a white flower with interesting petal patterns.

6.  All along the journey I couldnt help but observe this one flower that was widespread but showed different petal color patterns, either in different plants or in the same plant. This pattern brought back memories of my graduate student days. In a different life, I studied post-transcriptional gene silencing in plants, which over time got a fancier name– RNAi. This happens when the expression of a gene  is silenced, often  differentially in different cells. The patterns are most stark in colored petals due to silencing of genes in the flavanoid biosynthesis pathway. The plant biologists were the first to notice this phenomenon and did pioneering experiments to uncover the many mechanism involved in this (there is more than one distinct mechanism). Pity the Nobel committee didnt think their contributions enough to reward their efforts.

Under the foldscope, one can clearly seen the transition points between the colored cells and the non-colored cells.  The patterns too were not often consistent between flowers of the same plant, suggesting a kind of stochasticism. This brought back good and bad memories of the past—long hours of work often with no returns with glimpses of hope, and flashes of inspiration.

These had some of the largest pollen I have seen of size about 130-140 microns

7. Ooty and Coonoor are blessed with a wonderful lichen diversity. I did pick a few but didnt get much time to analyze them. In a desperate attempt to see if I can pick up nematodes and tardigrades I soaked them in water overnight and put some of that water on slides that I hadnt cleaned. The lichens were unsurprising, but some residual pollen that were on the slides suddenly started to give out pollen tubes. Could there have been something in the lichens that induced this? Now I really wish I had spent more time analyzing this, but it was time to catch my train– Am going to see if this is reproducible at home with lichen water and pollen.

P.S. @Manu  the below link of the surroundings and you might recognize what I was trying to do with the bottle.

2 Comments Add yours

  1. Manu Prakash says:

    Dear Laks.

    For several years I have tried to do a pollen tube growth experiment; tried different sugar solutions but have not succeeded in imaging them live. My understanding was that pollen has to land on the correct species of flowers and it’s a hand shake that leads to pollen tube growth.

    So I am beyond thrilled to see this; specially the fact that lichen led to pollen tube generation.

    wonderful – wonderful.

    Could I request you to also post a picture or two of beautiful surroundings in Ooty. I hope someone took a picture of you picking flowers and folds coping with the beautiful background.

    cheers
    manu

    1. laksiyer says:

      Dear Manu. I was really surprised with the pollen tubes. I must try this again at home. Just have no explanation as to why it worked. I have put up an animated gif of the place. I usually did all my sampling while others rested 🙂

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