Arabidopsis thaliana

Friday past to the Royal Institution to hear from Caroline Dean (Dame, FRS etc) about how plants use their molecular memory to keep track of the seasons, in particular the end of the winter so that they know when to move into flowering mode.

A warm afternoon, but a cooling north easterly breeze on the platforms at Epsom and a common wagtail on the country platform. No westbound aeroplanes to be seen out of the eastern windows anywhere between Raynes Park and Vauxhall.

Sign

At Vauxhall, I noticed that the traditional tube sign, blue bar on red circle had been modified, presumably to celebrate diversity. A change I for one could do without: celebrate diversity by all means, but not at the expense of our world famous sign.

On Green Park concourse a few seconds after 1819, the very time advertised by the Network Rail journey planner. A very useful application, with both Bing and Google bringing it up on all my various computers after the first two or three letters.

Goat very busy outside, fairly busy inside but there were four summer shirted bar staff on the case and I was served fast enough. Quiet enough upstairs, although the musak was irritatingly and unnecessarily loud.

Various arty premises in the area were sporting green balloons outside and people with drinks inside, including Mazzoleni, more or less opposite the Institution, the place with the expensive pipework noticed at reference 1. The young lady there explained that it was the Mayfair Art Week and they were trying to promote art by staying open until 2000. I declined champagne on the grounds that I could not stay, but I did take a look at an interesting work by one Nunzio in pride of place in their front window. A work made out of slats of carbonised wood, decorated with thin stripes of ultramarine paint; an effective work to which I shall return in a post to come.

Into the lecture theatre to learn that the people called Conversation noticed at reference 2 sponsor events on AI at the Institution. Perhaps now that I have noticed them, I will come across them more often.

Various worthy people sitting around me, some of them trusties in higher grade national institutions, places like Kew Gardens. While the sailing chap behind me explained to his lady friend that there no harbours worth the mention in Lyme Bay, which was tiresome if the weather cut up on your way across. There was something wrong with the harbour at Lyme Regis, but I did not catch what. And when he wasn't sailing, he did things like popping over to Rome for a few days.

Dame Dean turned out to be a small lady with a pleasant manner, with plenty of good material - although I did not think she got it quite right for a lay audience. Perhaps there was too much of it to take in. She worked from the John Innes Centre at Norwich, an establishment which had started life in Merton, in south London just over 100 years ago. And she mainly works on arabidopsis thaliana, possibly known to some readers as thale cress. See reference 4.

Thale cress

With this picture of two different sorts of thale cress plants taken from the slide show about same at reference 5. The spitting image of the three pairs of pots handed around the lecture. So given that there is a very international team at the John Innes Centre, perhaps the author, Virendra Singh Shekhawat, passed through at some point.

The point of interest of this plant is that it grows pretty much all over the world and knows when to wake up after the winter, where there is one, taking proper account of the varying length of winter in the various places. In cold climates they are winter annuals, getting off to a fast start in the spring; in warmer climates they are summer annuals; and, in hot climates they might get through several generations in the course of one summer. A timing process which is very important, for example, in things like flowering bulbs - which will not flower at all if it goes wrong - and in things like cauliflowers which which can be destroyed by frost if they get going at the wrong time. Then how do all the many thousands of plants in a field of wheat manage to flower and ripen at the same time? Where they talking to each other in some planty way? With a failing here making harvesting rather difficult. So working out how exactly thale cress does this vernalisation (as it is called) is a very worthwhile puzzle, and then, having worked it out for thale cress, it was likely that all these other plants used much the same machinery; evolution being fairly lazy.

Dame Dean did not tell us that thale cress is a very popular plant in plant physiology laboratories all over the world, the plant analogue of the nematode caenorhabditis elegans. One of the reasons for its popularity being that it can be bred very fast, down to a six week cycle if you are really in a hurry; another is that it has a very small genome, which meant that it was one of the first plant genomes to be read.

One surprise was that the story, when it had been deciphered was not that complicated and could be reasonably captured by one simple diagram. Nothing to do with talking to each other; rather it was all down to regulation of something called FL-C (for flowering locus C), a something which inhibited flowering. Something which made the growing cells head off down the leaf road, rather than down the flower road. With different plants having different ways of working on FL-C, some working on length of day and some working on average temperature. There was also some integration going on here so that, in some sense, the plant was able to add up how much cold there had been.

And with some gross features of plant life being tweaked by very small tweaks of the genome, perhaps as small as changing just one base pair.

Epigenetics also got into the story, being something, if I understood her aright, which qualified, which modified the workings of the genome in a cell, a something which is passed on through cell division but not through sexual reproduction. A new plant starts out with a blank slate.

While plant modelers, some of whom had a mathematics and physics background, got into learned debates about properties which were binary, that is to say on or off, and properties which took real values, say all the values between zero and one. With taking a mean value across a number of cells being one way to get from binary to real and applying a threshold being one way to get from real to binary.

All ably summarised at reference 6.

Nunzio's 'Avvoltoio'

A rather bad snap of the Nunzio, taken from the outside, after closing time.

Art Week

Another manifestation of the Mayfair Art Week, this one in Dover Street and decorated with Rolls Royce No.77A, perhaps a cabriolet at perhaps £75,000 a seat? Maybe I would have been a bit out of my league for a free drink at this one.

Stopped off at the Half Way House on the way home. Where I noticed that the two perfectly decent chaps sitting next to me did not think it necessary to push their chairs back in or tidy their table in any other way when they left. To my mind a lapse of manners. Maybe 40-50, maybe people who never had the discipline of eating together, at table, as a family.

Tree flowers

My Travelcard failed for the second time going back into Earlsfield, suggesting that the validation code on the (re-)entry gate has rules about how long one should stay in the pub. And still no aeroplanes to be seen heading west down to Heathrow from the country platform, despite the good viewing conditions. And only two flying in other directions.

On the other hand, all the trees flowering beyond the hedge were looking rather splendid, although they did not snap well, with that above being taken in Manor Green Road the following morning.

Mr. May at the G20

Back home, struck by the partners picture from the G20 meeting. Poor old Mr. May looked as isolated with the partners as Mrs. May tends to look with the presidents. But at least he does not look quite as uncomfortable about it.

Reference 1: https://psmv4.blogspot.com/2019/04/place-cells-episode-2.html.

Reference 2: https://psmv4.blogspot.com/2019/06/new-news.html.

Reference 3: https://www.jic.ac.uk/people/caroline-dean/.

Reference 4: https://en.wikipedia.org/wiki/Arabidopsis_thaliana.

Reference 5: https://www.slideshare.net/VirendrasinghShekhaw4/arabidopsis-thaliana-75527185.

Reference 6: https://journals.plos.org/plosgenetics/article?id=10.1371/journal.pgen.1003593. A 2013 interview with Dame Dean, in PLOS Genetics, covering much of the same ground.