Lichens, thale cress, tobacco, the great survivors…

Image: from Shokoku meisho hyakkei by Hiroshige II (Chinpei Suzuki), 1860.

Image: from Shokoku meisho hyakkei by Hiroshige II (Chinpei Suzuki), 1860.

It is often said that cock­roaches are one of the har­di­est of anim­als, allegedly able to with­stand a nuc­lear holo­caust. Well, ser­i­ous con­tenders amongst the plant-like crit­ters are lichens, thale cress and tobacco. Rhizocarpon geo­graph­icum and Xanthoria eleg­ans have both sur­vived a 1.5-year extra­ter­restrial sojourn aboard the International Space Station accord­ing to work by Silvano Onofri et al.

During their 2008–9 space odys­sey the lichens were exposed to space vacuum (as low as 10–7 Pa), galactic cos­mic radi­ation (£ 190 mGy), the full spec­trum of solar radi­ation (l > 110 nm), and tem­per­at­ures from –21.5 to 59.6 °C. Impressive? Yes, but even more impress­ive is the rev­el­a­tion by David Tepfer et al. that seeds of Arabidopsis thali­ana and Nicotiana tabacum exposed to sim­ilar con­di­tions also sur­vived (for 558 days), with ger­min­a­tion rates of 23 % and 44 %, respect­ively, back on the ground. In that lat­ter study the authors con­cluded that ‘a naked, seed-like entity could have sur­vived expos­ure to solar UV radi­ation dur­ing a hypo­thet­ical trans­fer from Mars to Earth’. I’m not sure if that means that it’s the Martians we must thank for the ‘gift of Arabidopsis’, or whether the return jour­ney is also pos­sible and that if we ever get to Mars at least the plant bio­lo­gists will be able to con­tinue to study their beloved thale cress (and tobacco – and maybe even lichens…)!

Nigel Chaffey. ORCID 0000-0002-4231-9082

Nigel is a botanist and full-time academic at Bath Spa University (Bath, near Bristol, UK). As News Editor for the Annals of Botany he contributes the monthly Plant Cuttings column to that august international botanical organ. His main goal is to inform (hopefully, in an educational, and entertaining way...) about plants and plant-people interactions.

3 Responses

  1. The tobacco is obvi­ously for a gift to the nat­ive Martians. Native Americans not under­stand­ing the con­sequences offered Columbus fruit and tobacco. Columbus ate the fruit & threw away the leaves.

  2. gringojay says:

    lichen likers :
    Sancho LG, de la Torre R, Horneck G, Ascaso C, de Los Rios A, et al. (2007) Lichens sur­vive in space: res­ults from the 2005 LICHENS exper­i­ment. Astrobiology 7: 443–454

    Raggio J, Pintado A, Ascaso C, De La Torre R, De Los Rios A, et al. (2011) Whole Lichen Thalli Survive Exposure to Space Conditions: Results of Lithopanspermia Experiment with Aspicilia fru­tic­u­losa. Astrobiology 11: 281–292