Measuring the pH of plant cell walls

New work out of Wolfgang Busch’s lab in Vienna, lead by Elke Barbez, describes a new and relatively simple method for measuring the pH of plant cell walls:

Here, we present a fluorescent dye that allows for the correlation of cell size and apoplastic pH at a cellular resolution in Arabidopsis thaliana.

I already ordered the dye, can’t wait to try it on some mutants!

I’m really pulling for the SpaceX launch scheduled for this week, as my colleague and friend John Kiss’s experiment is launching on it:

Our experiment uses the same hardware and facilities on flight as John’s, so I’m also really hoping everything goes well up there, otherwise we’ll have problems getting approved to launch.

UPDATE 2017-06-01: Today’s launch was scrubbed due to lightning in the area; they’re going to try again on Saturday.

Looking forward

Launch of SpaceX Dragon on a Falcon 9 rocket, 14 April 2015, Cape Canaveral, FL. Image credit: NASA

I’m looking forward to the day that my seeds are transported to the ISS on one of these babies! There’s still a long way to go before my project is even ready to apply for a flight position, but I’ve started working with support scientists to schedule all the tests that need to be done. It’s going to be a very busy summer around my lab!

Read more about today’s launch, known as the CRS-6, at NASA’s page about the mission.

Seeds can change their coats for the season

Whenever I teach on seeds, either in my non-majors Food class or my Plant Physiology class for majors, I can’t help describing them as the children of the mother plant. I know, not exactly creative, but it helps to paint a picture of the roles of the parent plant and the seed. I like to talk about how the endosperm or other food reserve is like a packed lunch, put there by the caring mother to feed the baby plant as it germinates and becomes able to feed itself. And what kind of parent sends its babies out without a coat? It usually gets a few chuckles, at least, to put this all in human terms.

That coat on the seed? Sometimes it’s a jacket, and other times it’s more like a down coat, and the mother plant chooses based on the temperature. I’m not making this up. In a study published this week, plant scientists link the toughness/thickness of the seed coat to the temperature endured by the mother plant. If the mother experienced warmer temperatures, it will make more of a protein that limits the production of tannins in the fruit. Less tannin makes for a thinner seed coat and faster germination. On the other hand lower temperatures cause the mother plant to make more tannins, leading to a thicker coat. Simple, yet remarkable.

See a news article on this research, or go check out the paper itself.

A writing project that bridges two worlds

For the last several months I’ve been working on a manuscript to be included in an edited volume tentatively called Plant Gravitropism: Methods and Protocols. It is part of a series called Methods in Molecular Biology, published by Springer.

rotating stage and camera systemMy contribution focuses on ROTATO, the image analysis and feedback system we use routinely in my lab to measure root gravity responses. The objective of the series is to allow “a competent scientist who is unfamiliar with the method to carry out the technique successfully at the first attempt,” which seems pretty unlikely to me. I can’t think of a single experiment that I’ve every carried out successfully on the first try, but that’s another matter. I’ve been surprised by how hard it’s been to write this, so I thought I’d do some thinking out loud to try to gain a little insight into my struggle.

I think some of my struggle has come from being too close to the method to see it with “beginner’s eyes.” I’ve been working with ROTATO since it was a pile of parts stripped from IBM PCs (we used the computer power supply for 5 V DC and the stepper motor from the floppy drive). I watched over my friend Jack’s shoulder as he wrote the software to make it work. I know the ins and outs of how it works and what makes for a good experiment. Through the years I’ve had a tough time teaching my students how to get good data with it, and I think that’s in part due to the hidden assumptions I make about it. Dragging those assumptions out into the light has been an ongoing process, and writing this paper has been helpful.

Another aspect of the struggle is with how to handle the software part of the method. I am not releasing the code (it’s not mine), and even if I could it wouldn’t do much good because of its dependence on an obsolete frame grabber card. So I’m trying to include enough detail about how it works to allow a scientist/programmer to reimplement the method. But I’m a biologist, not an engineer, so I’m struggling with how much to say and how to say it. I think this is the heart of the issue, that I’m trying to bridge the worlds of biology and engineering.

This is, in fact, what ROTATO is about, and what makes it so important. It takes pictures of a biological response and uses them to control the position of the organ doing the response. It is clever, naive in certain ways, clunky, finicky, crashy, and it works. It has allowed us to learn new things about how roots respond to gravity. So that’s what I’m trying to convey in this methods paper, how to make a ROTATO that works well enough to learn new things, of which there are plenty, I am sure.

Writing about science for the public

Some good bits of advice for writing about science for the public, including this one:

Readers can be very clever, but it is not their job to know all of the words that you and the twelve people you call colleagues made up.

I particularly like the focus on telling a people-centered story. This is so far from the comfort zone for most researchers, but I agree that it’s essential to effectively connecting.

Nutrients in vegetables vary according to the clock

You may not realize this, but most fruits and vegetables are still living when you eat them — this is what keeps them from turning mushy and limp. In a new study, researchers from Rice University have shown that these plants are not only living, but their metabolism continues to cycle in response to light/dark periods, influencing their nutritional quality:

“Vegetables and fruits don’t die the moment they are harvested,” said Rice biologist Janet Braam, the lead researcher on a new study this week in Current Biology. “They respond to their environment for days, and we found we could use light to coax them to make more cancer-fighting antioxidants at certain times of day.”

Evidence planted in an Oregon wheat field?

Several weeks ago, the USDA announced it had confirmed the presence of Roundup-Ready wheat in an Oregon field. Roundup-Ready wheat underwent field trials in the late 90’s and early 00’s, but trials were suspended before final approval was granted. The wheat is a match to the exact strain tested by Monsanto. Now it appears somebody may have planted evidence (sorry, couldn’t resist at least one bad pun):

“None of standard farming practices are consistent with, or can explain, a smattering in only one percent of a field or in patches or clumps,” he said. “In our view the finding is suspicious.”

The strain of wheat has never been shown to be harmful, and it carries the same genetic construct as several Roundup-Ready crops that have been approved. But the wheat has not completed the approval process, so the finding caused considerable concern.

Supreme Court ruling denies patent to DNA sequence

The Supreme Court ruled today in the case involving Myriad Genetics’ patent on the BRCA1 and BRCA2 genes. Thankfully, they found that DNA sequences are not patentable because they are a product of nature. The Myriad lawyers had argued that the acts of isolation and sequencing make DNA “inventions” rather than natural discoveries, but the court wasn’t buying that argument.

As I’ve noted previously, not only do I find Myriad’s argument wrong in theory, I also find it misleading in practice. They did not bear any of the costs or risks in actually discovering the sequences in the first place. These two genes were identified in an academic lab at the University of Utah. The original paper describing BRCA1 and BRCA2 acknowledges numerous NIH grants as the source of funding.

Most comments I’ve seen on Twitter seem excited or relieved about the ruling, including one by the NIH Director himself, Francis Collins:

Science writer Carl Zimmer linked to a blog post pointing out some factual errors in the ruling:

Comments on the blog post point out not only factual mistakes, but also an inherent contradiction in the reasoning of the ruling, which is more disturbing still. Details matter, and I’m not impressed by the way the law is (mis)interpreting molecular biology.