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In the plant kingdom, great size doesn't always guarantee ‘success’. Take for instance trees: for all their wonderfulness and huge size, they don't always scale the heights their stature might aspire to; they are held in check by a well-known and recognised tree-line (http://en.wikipedia.org/wiki/Tree_line). For example, the Alpine tree line, between 30 °N and 20 °S, is roughly constant at 3500–4000 m (11 500–13 000 feet). But some intrepid and enterprising – although otherwise small and seemingly insignificant – herbs can push the boundary higher than this. A new European record has probably been set by Saxifraga oppositifolia at 4505 m (14 780 feet) on Dom de Mischabel in the Swiss Alps (http://www.physorg.com/news/2011-05-4505m-swiss-alps.html), reported by Christian Körner of the University of Basel (Switzerland) in the appropriately entitled journal Alpine Botany (121:11–22, 2011). The magnitude of the saxifrage's achievement can be gauged by its regularly enduring <0°C during the night-time, winter temperatures down to –20·9 °C(!), and an average temperature throughout its growing season of only +2·6 °C. By contrast, summer can reach a positively sub-tropical +18·1 °C. To quote from the article, ‘these data illustrate the life conditions at what is possibly the coldest place for angiosperm plant life on earth’. In the interests of balance, one ought to add that other life forms were found with the angiosperm at this site (but not trees!). However, and as with humans, the high-life is not without its down-side as it seems that seeds of alpine plants are shorter-lived than those of lowland plants. Consequently, as Andrea Mondoni et al. (Annals of Botany 107: 171–179, 2011) conclude, ‘Long-term seed conservation of several alpine species using conventional seed banking methods will be problematic’.
Image: Michael Haferkamp/Wikimedia Commons.
In the good old days of the late 18th Century in England it was considered the height of scientific enquiry for a polymath cleric to put a mouse in a bell jar to demonstrate that animals could be sustained by the dephlogisticated air – oxygen – conveniently released by plants during the then unnamed-and-even-now-not-entirely-understood process of photosynthesis (http://en.wikipedia.org/wiki/Joseph_Priestley). Nowadays, however, that is not enough. With the lay public's assumed obsession with ‘celebrity’ and ‘reality’ television, we need a real live human being-type person for this sort of stunt. And not just anybody, but a Scientist! Or such seems to be the thinking behind the latest headline-grabbing activity at the UK's Eden Project (sited in a former clay quarry complex in the would-be break-away Republic of the county of Cornwall; http://www.bbc.co.uk/news/uk-england-14843911). In this graphic demonstration of the power of plants to sustain animal life, British TV's Iain Stewart (former child actor and academic geologist – http://en.wikipedia.org/wiki/Iain_Stewart_%28geologist%29) was sealed in a 6 m (or 8 m depending on news source!) × 2 m × 2.5 m airtight chamber for 48 hours with only a group of plants (admittedly, reasonably photosynthetically efficient ones such as C4 species …) as an oxygen source. Fortunately, somebody left the lights on (throughout the whole two days, so goodness knows what the carbon footprint of this ‘experiment’ was!). You'll no doubt be pleased to discover that Iain survived his ‘ordeal’ (http://www.edenproject.com/media/bell-jar-retrospective-pr.php). The event was filmed for inclusion in a new BBC (British Broadcasting Corporation) Two series, ‘How Plants Made The World’, which may be broadcast in 2012. When not putting his life in the hands of bananas, miscanthus, maize, etc, Iain is Professor of Geoscience Communication at the University of Plymouth (http://www.plymouth.ac.uk/staff/istewart), a job title that could have been made for him. The activity raises many questions, but my main one is: why couldn't we find a BOTANIST prepared to put his money where his stoma is …? Still, as long as this helps to promote our reliance on the plant kingdom and our need for more plant biologists, it's as well someone volunteered, however shy and publicity-averse they may be.
Image: Anna Lætita Barbauld (née Aikin), Poems (1773). From Poems: a hypertext edition, eds. Lisa Vargo & Allison Muri, University of Maryland.
This column is always interested in cross-Kingdom co-operation (especially if it involves plants!), but some ‘associations’ go too far, and often in weirdly and wonderfully unexpected covert ways and make you wonder where one kingdom ends and another begins. Take, for instance, the news that microRNAs (http://en.wikipedia.org/wiki/MicroRNA) from dietary staples such as rice can not only be found in the blood and tissues of humans and other plant-eating mammals, but that those botanical biomolecules may actually influence gene expression in their new hosts. Lin Zhang and colleagues found that MIR168a, which is highly enriched in rice, inhibits a protein that helps remove low-density lipoprotein (LDL) from the blood (Cell Research; http://dx.doi.org/10.1038/cr.2011.158), at least in mice. If more widely applicable this finding is likely to have implications for dietary management of cholesterol (http://en.wikipedia.org/wiki/Cholesterol) levels in humans since elevated amounts of LDLs are associated with health problems such as cardiovascular disease (http://en.wikipedia.org/wiki/Low-density_lipoprotein). Perhaps this is the plant way of telling us not to eat them after all? And this is on the back of news that ribosomes may exert control over what RNAs they actually ‘decide’ to translate. Working with mice, Nadya Kondrashov et al. present evidence that ribosomes can regulate gene expression, in some instances (Cell 145: 383–397, 2011). Famously, ribosomes are largely considered ‘just’ to facilitate the translation of messenger RNA into polypeptide chains during protein synthesis by providing a physical substrate where this can take place (yes, I know I'm simplifying it a bit; http://en.wikipedia.org/wiki/Protein_biosynthesis). This work is regarded highly enough to have been post-publication peer-reviewed by the Faculty of 1000 (http://f1000.com/10149956?key=hn01j5t6y9slb3d). I don't know, which bit of the cell is in control? Is this now an example of feed-back, or feed-forward? Either way, it seems that the more you dig the more you find that it's feeding every which way. In any event, this represents another ‘trophy’ for the cell biology hall of fame. By way of turning the tables somewhat away from plants and back in favour of animals, Jonathan Kingdon and colleagues tell the tale of the African crested rat (Proceedings of the Royal Sociey, B; http://dx.doi.org/10.1098/rspb.2011.1169 – spot the seamless mouse–rat link?). This rodent has developed the interesting trait of ‘unpalatability by appropriation’ in which it gnaws, masticates and slavers toxins acquired from the roots and bark of Acokanthera schimperi (Apocynaceae) onto highly specialised hairs. The poison (a cardenolide, closely resembling ouabain; http://en.wikipedia.org/wiki/Ouabain) is one of the active components in a traditional African arrow poison long celebrated for its power to kill elephants(!). But being a sporting kind of critter, ‘Ratty’ advertises its possession of this particularly potent plant poison to would-be attackers.
Image: Wikimedia Commons.
In Chaos Theory (http://en.wikipedia.org/wiki/Chaos_theory), the butterfly effect refers to the notion that a small change at one place can result in much larger differences to a later state (http://en.wikipedia.org/wiki/Butterfly_effect). The example used to illustrate this – and which gives the phenomenon its rather poetic name – is that of a hurricane's development being contingent upon the flapping of a butterfly's wings some time before. Well, possibly a more obvious ‘butterfly effect’ has been recorded by NASA (the USA's National Aeronautics and Space Administration) with its Aura satellite (http://www.sciencedaily.com/releases/2011/07/110715162908.htm). One of its images (pictured here) – of NO2 levels in central Africa in July 2011 – shows a red butterfly-like pattern that represents the highest levels of NO2 over the southern Democratic Republic of the Congo. The NO2 results from agricultural fires in which croplands are burnt to clear fields post-harvest, and to encourage new growth in pastures for grazing animals. Unfortunately, NO2 is a major air pollutant (http://en.wikipedia.org/wiki/Nitrogen_dioxide) that generates low-level ozone in the presence of sunlight, which in turn contributes to smog and poor air quality. And being gaseous the effects are felt not just in the vicinity of the fires, but democratically shared further afield; the smog (http://en.wikipedia.org/wiki/Smog) affects plants and animals, contributing to respiratory problems in humans. In addition to NO2, the satellite-mounted ozone monitoring instrument (OMI) gives daily global coverage of key air quality components such as SO2 and aerosol characteristics, and provides mapping of pollution products from an urban to super-regional scale (http://aura.gsfc.nasa.gov/instruments/omi.html). Although recording these potentially damaging pollution events doesn't necessarily stop them being produced it is an important step in understanding their source and prevalence.
Image: NASA/James Acker.
Exposure to ultraviolet (UV) radiation is generally regarded to be deleterious to biological systems (http://en.wikipedia.org/wiki/Ultraviolet#Harmful_effects); however – like many potentially bad things – in small doses it may actually be beneficial. Well, that is what Jason Wargent and co-workers have found (Plant, Cell & Environment 34: 1401–1413, 2011). The UK-based research found that exposure of lettuce (Lactuca sativa) to UV-B in the early stages of growth led to increased photosynthetic activity and consequently higher yield(!). Or, in the more guarded parlance of the scientific paper, ‘Our findings suggest that earlier exposure to realistic levels of UV radiation leads to positive photosynthetic performance and other protective changes in leaf morphology, and when combined with enhanced photoprotection to high light and temperature as observed under controlled conditions, these early-stage effects driven by UV-B appear to enhance plant tolerance against generalized field transplantation stresses to a greater capacity, which can then lead to increased productivity in a longer-term field growth environment’. Rather than repeat that, and in case you've missed the potential importance of this finding, the article's abstract usefully concludes thus, ‘Our findings are discussed within the context of sustainability in agriculture and the paradigm shift in photobiology [slight emphasis added by me] which such beneficial responses to UV radiation could represent’(!!). And – because I know you're wondering – I'm not aware that the famous leafy culinary vegetable's green colouration was darkened by the treatment (by analogy to the tanning effect that occurs in human epidermides upon exposure to UV). So, your principal salad component should still be green (though why anybody eats the unsatisfying so-called foodstuff in the first place is beyond me).
Image: David Shankbone/Wikimedia Commons.
CITES (the Convention on International Trade in Endangered Species of Wild Fauna and Flora – apparently, also known as the Washington Convention) is a treaty whose aim is to ensure that international trade in specimens of wild animals and plants does not threaten the survival of the species in the wild. Enacted in 1975, it offers varying degrees of protection to approx. 28 000 plant species (http://www.cites.org/eng/disc/what.php). The trouble is that the organisms ‘covered’ by CITES are – by definition – endangered and often in short supply. Consequently – sadly, economics applies in the biological arena as well as more human-sociological ones – those biologics are often in high demand, as ornaments, etc, in homes, offices, conference venues … So a CITES tag can actually be viewed as a price tag, the more highly endangered – and ‘cited’ – the organism, the more valuable. And there are ne'er do wells in the world for whom trade in such exotic taxa is a very lucrative business (allegedly). Keeping a lid on this aspect of the black economy (http://www.economypedia.com/wiki/index.php?title=Black_economy) is difficult and policing the movements of the affected organisms is not necessarily the world's number one priority. However, a relatively recent innovative procedure may just help to track such portable commodities as expensive botanics. Andrea Luvisi et al. expound on the merits of embedding microchips within ornamental shrubs (HortTechnology 20: 1037–1042, 2010). Developing the concept with roses they found that such shrubs should be safely tagged – internally – with a RFID (radiofrequency identification) microchip as early as the nursery phase, and without negative effects on plant appearance. We look forward to this being rolled out to more endangered plants in the near future. And let's hope this news is timely enough to help the 75 vascular plants (along with 13 amphibians, 17 beetles, 81 crayfish, and 6 non-vascular plants …) whose endangered/protected status in the USA – under its own Endangered Species Act – is due to be reviewed by the United States' Fish and Wildlife Service (http://onlinepressroom.net/fws/ – 26 Sept. 2011 news release). Hmm, chips with everything? Now you're talking!
Image: Rainer Zenz/Wikimedia Commons.
Whilst physicists try to understand the implications of, and undo any harm done by, the announcement that certain particles can travel faster than the speed of light (http://www.nature.com/news/2011/110922/full/news.2011.554.html), others are capitalising upon this phenomenon, to the advantage of plant biology in particular. Already there are reports that a ‘faster-than-light’ microscope is being built. The so-called FLiM will be used to study plant embryos to see if phylogeny really does recapitulate ontogeny, or maybe the other way round (http://en.wikipedia.org/wiki/Recapitulation_theory). Regardless of the attendant flim-flam, I suspect hackles will rise at that notion. In an even more ambitious project, reasonably intelligent designers are fabricating a device that will travel back in time, and which will allow its passengers to see if evolution really happened. Science fact or science friction? Who knows, but this project is determined to create more light than heat in its execution. The craft – nicknamed (in a competition won by a Mr R. Dawkins [not his real name?] of ‘Oxbridgeshire’) the ‘Dar win-win’ – will also be used to establish once-and-for-all why Photosystem II works first and Photosystem I works second in photosynthesis (http://en.wikipedia.org/wiki/Photosystem), and to rule on whether the serial endosymbiotic notion of eukaryotic cell evolution (http://en.wikipedia.org/wiki/Endosymbiotic_theory) is actually a Hypothesis, a Theory, a Law, or whatever. There are also stories that a rival device is being created that will be crewed by PhDs from the World Health Organisation. The aim of that ship full of Dr WHOs is to identify crop pests and eradicate them before they blight lives, etc (the fact that this may well change the course of history is not something they appear to have considered). That craft – christened the Higgs – will be ready for launch just as soon as they've found the final crew member, the hitherto elusive boatswain (http://en.wikipedia.org/wiki/Boatswain). Travelling faster than a speeding pullet (http://en.wiktionary.org/wiki/pullet) – to paraphrase Superman's famous tag line (http://www.imdb.com/title/tt0034247/quotes), at least one of these time machines should also be able to answer the age-old conundrum of whether the egg – or the chicken, we're not ovocentric here! – came first, both ends of the poultry spectrum having previously claimed this primacy (http://newsfeed.time.com/2010/07/14/the-chicken-and-the-egg-ancient-mystery-solved/ and http://www.guardian.co.uk/science/2006/may/26/uknews). Presumably, time(!) will tell if all of this is just another good particle delusion and that physics is actually still OK, or not …. [Each of these so-called time machines is officially a TARDIS – This Article Really Doesn't Include Science – Ed.]
Image: Arthur Sasse/United Press International, 1951.
Chaffey N. 2011. Plant Cuttings, November. Annals of Botany 108(7): iii–v.