Dark Virginia in DDW

Updated Preliminary Tobacco Seed Growth “Results”

Those are images of the first batch of samples (Dark Virginia seeds, not pre-soaked), I’ll take pictures of everything and post it next week. But here are the preliminary reports of what different water types do to tobacco seeds:

  • Every seed submerged in deuterium depleted water (DDW) sprouted little hairs on the initial root (the radicle). The interesting thing is this happened almost immediately after emerging from the seed coat.
  • Typically the seeds submerged in deionized water (DI water) germinated the slowest. More will come on this when I replicate the Crumley experiment.
  • Little hairs sprouted inconsistently on the seeds in tap and DI water but are more prevalent on the DI water seedlings. They are not as abundant on these seedlings as they are on the ddw seedlings. If I had to give an analogy (and I do) then I would say the ddw seedlings can grow a nice ‘fro, while the other seeds exhibit male pattern baldness.
  • The little hairs remain localized on the end of the root and aren’t distrubted along the hypocotyl (early stem, and I almost said axon, lol!) so I’m inclined to believe that this is an early root system that is developing because of a lack of nutrients in the water (seen on ddw, most DI, and almost no tap water seeds). But I’m no botanist so I’m just guessing. The fact that the hairs are really prominent in the ddw seeds might suggest the plant recognizes the lack of deuterium, but I’m not willing to make that leap yet.

I setup a new photography system for these seeds. Dr. Koch lent me his Nikon D40 dSLR camera and I purchased some magnification lenses for it. I have the camera setup on an optical post and use a cylindrical lens holder to mount the seed samples (in cuvettes). The picture quality is much better now, with a much higher resolution. I’ll be looking into microscope images soon. Soon I’ll be developing a reliable way to measure the germination, but let’s not jump the shark now. All will be revealed in due time.

Also I was going to measure the pH of the samples at this stage of their development to gain some insight into whether the germination event drastically alters the pH, but the probe in the lab is too big and I don’t have enough sample volume. So I’m thinking that next week I combine the volumes of the water (of each type) to do one “average” measurement. There are four samples of each water type, two for each seed species, and each is filled about 2ml which would give me 8mL of combined volume for each water type. I’m just waiting for the pre-soaked samples to reach full germination (ie shed the seed coat). Now I’m not saying this will work, and it may not be reliable, but hopefully it is a decent approximation for expectations for now until I learn a little bit more.

  • http://stevekochscience.blogspot.com Steve Koch

    The little hairs on the radicle in deuterium-depleted water are fascinating. Seems to me it may be real and repeatable. I’m thinking it’s very much worth pursuing with further questions, and maybe is a good first phenotype that we can use to test Lewis’ 1934 hypothesis. As you state, very, very preliminary. How do we make it more solid? First of all, is it really happening? How about other seeds, like Arabidopsis? More varieties of tobacco? How do we know the DDW isn’t contaminated with a trace of something that causes it? This is a very difficult question. How do we get to the point that a biologist will take us seriously? Can we get multiple sources of DDW? What if you mix DDW with DI water or heavy water to add back in deuterium? This is one imperfect way to assess whether it’s a contaminant in the DDW: you can set the level of deuterium to be the same by adding either DI water or heavy water, but the DI water will dilute the DDW (and hypothetical contaminant) much more. What is the deuterium content of DI water anyway? It’s probably somewhat different than “standard mean ocean water,” due to the purification process.

    All of those questions are really difficult. Nevertheless, I think the “afro radicles” are super-exciting! Good work!

    • http://www.iheartanthony.com Anthony Salvagno

      Lewis actually had a decent hypothesis as to perhaps how to figure this out. He suggested dissolving nutrients in the water type of our wishes (in his case D2O) and then letting the water evaporate and then adding a fresh batch of the water type that was in there. This method may minimize/maximize the D-exchange with the H’s already in the chemicals to minimize it when we add the fresh buffer. And could be worth trying (and I will) real soon.

      Also I ordered some supposedly air tight petri dishes that have a slide bottom so we can analyze on the microscope is need be. I also ordered way more seeds (like 1000) and will order other plant varieties. I made additions to the mind map but won’t be updated til my tablet hits wi-fi with some experiments that I think are easy, and worthwhile.

  • http://stevekochscience.blogspot.com Steve Koch

    I think your current plan for pH-ing is a dead end. You’re right pH is super important. But the mix-n-measure won’t tell much. I think making buffered solutions without changing the deuterium content (too much) will be necessary. You’re definitely right that if the hairs are a sign of distress, there are many things that could cause it (such as pH) besides deuterium-depletion.

    • http://www.iheartanthony.com Anthony Salvagno

      It was more of a playing around with samples that I know aren’t very good, clean experiments.

  • http://stevekochscience.blogspot.com Steve Koch

    You’re going to have to become a ninja at working with pure water with exact components (especially deuterium, hydrogen; buffer components; no contaminants) and very very clean work. This is a never-ending goal, different than your previous work, and you’ve made big strides already and I’m glad. Lots of hard work remaining.

  • http://stevekochscience.blogspot.com Steve Koch

    An end-of-September goal is to develop a good method for archiving / backing up this notebook. I can help with figuring out what scripts / code we’ll need to write. Maybe our collaborator, Rob Olendorf in library sciences can help. Or maybe someone from the “crowd.”

    • http://www.iheartanthony.com Anthony Salvagno

      Maybe there is an easy way to save posts from the RSS feed. Talking with Rob would be good, but in the meantime I’ll look up something else. We should make a mindmap timeline of goals.

  • http://stevekochscience.blogspot.com Steve Koch

    A mid-November goal is to figure out how to automatically collect links to your notebook entries. Disqus you’ve already set up, obviously. I don’t know how to do it with FriendFeed, Facebook, Google+, etc. E.g., I’ve linked to this entry in a few places:

    * Google+ https://plus.google.com/110146523961072500429/posts/44DL4B6uuyt

    * FriendFeed http://friendfeed.com/stevekoch/4da6b592/anthony-open-notebook-science-entry-on-very

    * Facebook https://www.facebook.com/skoch3/posts/261507347207557?notif_t=like

    • http://www.iheartanthony.com Anthony Salvagno

      Well right now I have the entries automatically on friendfeed, and they also automatically get tweeted to @Thescienceofant. I should figure out a way to get +1 buttons on my posts though, which shouldn’t be all that difficult (since I already have a facebook, tweet, and stumbleupon and email this buttons.

      • http://stevekochscience.blogspot.com Steve Koch

        I meant the opposite: so if someone comments on your friendfeed, it will show up or at least the thread will be linked here on your notebook.

        • http://www.iheartanthony.com Anthony Salvagno

          Oh I see. That makes sense and would be really useful. I’ll have to see if there is anything like that that exists. I know there are sites that just use facebook to comment which is only like 25% of what you are talking about. There might be something in the reactions, which is a feature that tracks when my post gets posted somewhere else. I’ll definitely look into that real soon.

        • http://www.iheartanthony.com Anthony Salvagno

          Oh I see. That makes sense and would be really useful. I’ll have to see if there is anything like that that exists. I know there are sites that just use facebook to comment which is only like 25% of what you are talking about. There might be something in the reactions, which is a feature that tracks when my post gets posted somewhere else. I’ll definitely look into that real soon.