Brachypodium distachyon is considered a powerful model system to study the response of temperate cereals to adverse environmental conditions. Colton-Gagnon et al. examine cold acclimation and freezing tolerance in seven diploid accessions, and find that cold treatment accelerates the transition from the vegetative to the reproductive phase in all of them. This is associated with the gradual accumulation of BradiVRN1 transcripts, and the accessions exhibit a clear cold acclimation response by progressively accumulating proline, sugars and COR gene transcripts. However, whole-plant freezing tests show that the accessions only have a limited capacity to develop freezing tolerance when compared to winter varieties of temperate cereals such as wheat and barley. Furthermore, little difference in terms of survival is observed among the accessions tested despite their previous classification as either spring or winter genotypes.
The Indian Botanists have a review of ‘Green Wars- Dispatches from a Vanishing World’ by Bahar Dutt as well as an interview with her about the book.
Bibliodyssey, the art history blog, has a post on pomology and some illustrations from the 19th century.
I’ll assume you’ve already seen the Agricultural Biodiversity Weblog’s Nibbles.
Analysis of cellular patterns in plant organs provides information about the orientation of cell divisions and predominant growth directions. Raczyńska-Szajgin and Nakielski study patterns in the epidermis of asymmetrical wild-type dorsal petals and symmetrical dorsalized petals of the backpetals mutant of Antirrhinum majus (snapdragon) to determine how growth in initially symmetrical petal primordia leads to the development of mature petals differing in their symmetry. They find that during primordia development a characteristic fountain-like cellular pattern is maintained with only slight modifications, and petal cells divide in non-random directions. These features of the cellular pattern are presumably related to principal directions of growth. Two scenarios are considered to explain how gradual modifications in these directions may contribute to the transition from a symmetric to an asymmetric cellular pattern in the wild type petal.
Shoot characteristics differ depending on the meristem tissue that they originate from and the environmental conditions during their development. Negrón et al. observe and model the effects of plant water status on axillary meristem fate and flowering patterns along proleptic and epicormic shoots of almond trees, Prunus dulcis. They find that the two shoot types differ in their patterns of axillary meristem fates along the shoot, and in their axillary meristem fate responses to water stress. The structure of proleptic shoots is more sensitive to water stress than epicormic shoots and reflects differences in their ontogenetic status as well as growth rate patterns during the season.
Clonal spread influences genetic structure and diversity in plant populations as well as their realized outcrossing rate. Using microsatellite markers, Somme et al. investigate genetic diversity and the effect of clone distribution, structure and size on the mating of bee-pollinated marsh cinquefoil, Comarum palustre (Rosaceae), which is a rare, self-compatible species that grows in endangered European wetlands.
They find that clones are spatially clumped, with intermediate to no intermingling of the ramets, and large clones show lower outcrossing rates than small clones. Pollen dispersal mainly occurs within patches with very few pollination events occurring between patches of more than 25 m separation.These factors need to be taken into account in management strategies for ensuring population persistence.
A collection of papers on Extrafloral Nectaries has recently moved into Free Access at Annals of Botany. One of the papers raises the question, can a plant that never flowers have extrafloral nectaries?
Nectar secretion on fern fronds associated with lower levels of herbivore damage: field experiments with a widespread epiphyte of Mexican cloud forest remnants by Koptur et al. examines why ferns produce nectar. The paper starts with a brief review which includes a few facts that startled me. One is that extrafloral nectaries evolved before floral nectaries. This surprises me because I so deeply associate nectar with flowers. Another shock was that nectaries appear on ferns well before ants appear in the fossil record.
This shouldn’t be a surprise, but we’re so used to evolutionary stories being teleological, like plants evolved nectaries to reward insects, that it’s easy to forget that it’s a huge oversimplification that gets things very wrong. Nectaries didn’t evolve in order to do something with a purpose. Instead that plants with nectaries have a better chance of passing their traits to their offspring because they can reward insects. And what if there are no insects? Koptur et al. say that the early appearance of nectaries supports the ‘leaky phloem’ hypothesis, that sugars are forced out of the plant in weak developing tissues to ease hydrostatic pressure in the plant. This might explain how they formed, but once ants arrived did they help select ferns with better nectaries. Do the nectaries in ferns given them an evolutionary advantage?
The nectaries are on the leaves or fronds of the plant. Developing fronds are a prime target for herbivores, so if the ants were drawn into the leaves they could act as a defence. But do they. The experiment, like many of the best ones, sounds quite simple.
At its simplest, you find a plant with a suitable pair of young fronds. On one you paint over the nectaries with nail polish to prevent access to the nectar. You then see how the plants develop and compare the damage on the untreated leaf with the test leaf. Reality is messy, so they actually did a lot more than that to account for other factors – but the basic experiment was does access to the nectaries matter?
The results were clear. The fronds with blocked nectaries had four times the damage of the untreated fronds. The ferns benefited from hosting plants, and the ones that could attract them best got the best defence. The defence works best against invasive species that haven’t co-evolved with the fern and developed counter-defences against the ants.
It’s easy to see nectar as part of the plant’s reproductive strategy, or maybe as part of the reproductive system that’s been repurposed for something else. I think this paper neatly shows that there’s no need to assume any connection at all. There’s a lot more to nectar than bait for pollination.
Quora is a site for posting questions to the internet. Sometimes those questions get answer. For example Robert Frost, who has trained astronauts for the International Space Station, has answered the question: How are plants growing in the ISS?
Gravity is not the only difference between the Earth environment and the ISS environment. In the closed atmosphere of a spacecraft, volatile organic compounds (VOCs) can accumulate. VOCs need to be scrubbed from the air or seed production will suffer. There are elevated radiation levels that can cause mutations and affect growth. An experiment on Mir, that involved storing tomato seeds in space for six years found mutation rates up to 20 times higher in the space seeds than in the control seeds stored on the ground. And there are the spectral effects of using only electric lighting.
Because plants also respire, we have to have fans to circulate the air around the plants so that they don’t suffocate on their own exhalations. Even failed experiments can provide us with better understanding. An experiment to study plant lignin failed to produce healthy plant materials but taught us more about providing effective air movement.
You can read more at Quora.
Annals of Botany had an editorial meeting recently one of the topics that came up was how can authors increase the readership of their paper? One place that can have a surprisingly large impact is the abstract.
If you’ve spent an age trying to get all the details of your research right, it can be painful reducing everything to a couple of hundred words. However an abstract isn’t a mini-version of your paper, it’s a tool to get people to read your paper, and that means making it as easy as possible for people to see why they should care. There’s the full slidedeck up at Haiku Deck or press play above.
Botany is not without its mysteries. And one that’s previously eluded solution for 600 years or so is that of the so-called Voynich manuscript, an illustrated codex (a book made up of a number of sheets) consisting of about 240 pages, hand-written in an unknown writing system. Carbon-dated to the early 15th century, there are nevertheless suggestions that it might not be an ancient language but a hoax. And, despite containing many images of plants and other biological entities, its message and purpose has remained obscure (although an imaginative botanical interpretation is that it might represent a mediaeval plant physiology treatise). However, Stephen Bax, Professor of Applied Linguistics at the University of Bedfordshire (UK) has now claimed to have begun to decipher the manuscript’s text.
Progress is slow, but amongst the first few words to have been revealed are juniper, taurus, coriander, Centaurea, chiron, hellebore, Nigella sativa, kesar and cotton. A confident Bax declared, ‘… my research shows conclusively that the manuscript is not a hoax, as some have claimed, and is probably a treatise on nature, perhaps in a Near Eastern or Asian language’. Clearly, some way to go before we have a final, complete version, and can use it as a set text in plant physiology classes (so don’t throw out Taiz & Zeiger’s Plant Physiology just yet!). But another ancient manuscript whose purpose is more obvious is the Tractatus de Herbis (‘Treatise on Medicinal Plants’), a manual of materia medica [‘a Latin medical term for the body of collected knowledge about the therapeutic properties of any substance used for healing (i.e., medicines)’] compiled during the 15th century. This tome has been reproduced in a limited edition facsimile replica of 987 copies (price available ‘on request’, though I suspect that if you’ve got to ask how much it is, you can’t afford it…). This limited edition is accompanied by a full-colour commentary volume by Alain Touwaide,Research Associate of the Department of Botany at the Smithsonian National Museum of Natural History, USA and Scientific Director of the Institute for the Preservation of Medical Traditions at the Smithsonian in Washington, DC (USA).
[If you want to view the Voynich manuscript – for free! – it is available on-line. Even if the majority of the words are elusive, the images are quite wondrous… For more Voynich images and interpretations – e.g. putative plant identifications – Ellie Velinska’s blog is worth a visit – Ed.]
A few links have come in through the feeds today on urban botany. It could be interesting if you can’t get away for a holiday. Urban Botany, Urban Art and the Instagram Effect by Hollis Marriot at In the Company of Plants and Rocks blogs a botanical tour around Laramie. The juxtaposition of natural and urban elements like graffiti, can be striking.
If I have a mission, it’s to persuade people that every street is a garden. Not has a garden, note; but is one.
As she finds, it can be a tough claim to defend, but given the tenacity of plants, she might well be right.
Returning to plants and art, the tenacity can be an artistic tool in itself. I wandered on to Moss Graffiti, using moss as the ink for art. which Heavy Petal covered this back in 2007, so I’m quite slow. There’s a number of Pinterest images up, some very impressive and a how to guide at Stencil Revolution.