Tetradesmus deserticola SNI-2
The green alga Tetradesmus deserticola L. A. Lewis & Flechtner 2019 is a desert-dwelling species that belongs to the order Sphaeropleales in the class Chlorophyceae. Formerly referred to as Scenedesmus deserticola L. A. Lewis & Flechtner 2004 or Acutodesmus deserticola E. Hegewald, C. Bock & Krienitz 2013, the currently accepted name is Tetradesmus deserticola L. A. Lewis & Flechtner 2019. A permanent slide is deposited at the George Safford Torrey Herbarium, University of Connecticut, Storrs, CT, USA. (CONN00226458).
Unlike in aquatic Tetradesmus species that often form microcolonies in liquid culture, the morphology of T. deserticola is unicellular. Cells are variable in shape, ranging from crescent to lemon-shaped with pointed ends when young, becoming oval to almost spherical with age. It divides asexually by multiple fission, releasing 2-8 cells per division cycle.
T. deserticola is an extremophile, adapted to very arid environments such as those in the deserts of the Western US. It is extremely desiccation tolerant in its vegetative stage. It can survive multiple cycles of fast drying (< 15 minutes) and, upon rehydration, recovers photosynthetic activity immediately.
T. deserticola was isolated by Prof. Louise Lewis (University of Connecticut) from a biological soil crust collected from the desert soil surface in San Nicolas Island, CA, USA. 33.2°N119.2°W. (Collection date: July 1993, J. Belnap). This strain, SNI-2, is the holotype of the taxon. Live cultures were obtained from Prof. Lewis at the University of Connecticut.
References
Cardon, Z. G., Peredo, E. L., Dohnalkova, A. C., Gershone, H. L., & Bezanilla, M. (2018). A model suite of green algae within the Scenedesmaceae for investigating contrasting desiccation tolerance and morphology. J Cell Sci, 131(7), doi: 10.1242/jcs.212233.
Peredo, E.L. and Cardon, Z. G. (2020) Shared upregulation and contrasting downregulation of gene expression distinguish desiccation tolerant from intolerant green algae. PNAS, 117(29):17438-17445, doi: 10.1073/pnas.1906904117
