The Society for Integrative and Comparative Biology
Desiccation Tolerance in Bryophytes: A Reflection of the Primitive Strategy for Plant Survival in Dehydrating Habitats?1
1 USDA-ARS, Cropping Systems Research Laboratory, 3810 4th St, Lubbock, Texas 79415
2 University Herbarium, Jepson Herbarium, and Department of Integrative Biology, University of California, 1001 Valley Life Sciences Bldg # 2465, Berkeley, California 94720
Bryophytes are a non-monophyletic group of three major lineages (liverworts, hornworts, and mosses) that descend from the earliest branching events in the phylogeny of land plants. We postulate that desiccation tolerance is a primitive trait, thus mechanisms by which the first land plants achieved tolerance may be reflected in how extant desiccation-tolerant bryophytes survive drying. Evidence is consistent with extant bryophytes employing a tolerance strategy of constitutive cellular protection coupled with induction of a recovery/repair mechanism upon rehydration. Cellular structures appear intact in the desiccated state but are disrupted by rapid uptake of water upon rehydration, but cellular integrity is rapidly regained. The photosynthetic machinery appears to be protected such that photosynthetic activity recovers quickly. Gene expression responds following rehydration and not during drying. Gene expression is translationally controlled and results in the synthesis of a number of proteins, collectively called rehydrins. Some prominent rehydrins are similar to Late Embryogenesis Abundant (LEA) proteins, classically ascribed a protection function during desiccation. The role of LEA proteins in a rehydrating system is unknown but data indicates a function in stabilization and reconstitution of membranes. Phylogenetic studies using a Tortula ruralis LEA-like rehydrin led to a re-examination of the evolution of desiccation tolerance. A new phylogenetic analysis suggests that: (i) the basic mechanisms of tolerance seen in modern day bryophytes have changed little from the earliest manifestations of desiccation tolerance in land plants, and (ii) vegetative desiccation tolerance in the early land plants may have evolved from a mechanism present first in spores.
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  A. J. Charron and R. S. Quatrano Between a Rock and a Dry Place: The Water-Stressed Moss Mol Plant, May 1, 2009; 2(3): 478 - 486. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 X. Q. Wang, P. F. Yang, Z. Liu, W. Z. Liu, Y. Hu, H. Chen, T. Y. Kuang, Z. M. Pei, S. H. Shen, and Y. K. He Exploring the Mechanism of Physcomitrella patens Desiccation Tolerance through a Proteomic Strategy Plant Physiology, April 1, 2009; 149(4): 1739 - 1750. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M.-S. Liu, C.-T. Chien, and T.-P. Lin Constitutive Components and Induced Gene Expression are Involved in the Desiccation Tolerance of Selaginella tamariscina Plant Cell Physiol., April 1, 2008; 49(4): 653 - 663. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. A. Rensing, D. Lang, A. D. Zimmer, A. Terry, A. Salamov, H. Shapiro, T. Nishiyama, P.-F. Perroud, E. A. Lindquist, Y. Kamisugi, et al. The Physcomitrella Genome Reveals Evolutionary Insights into the Conquest of Land by Plants Science, January 4, 2008; 319(5859): 64 - 69. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. Hajek and R. P. Beckett Effect of Water Content Components on Desiccation and Recovery in Sphagnum Mosses Ann. Bot., January 1, 2008; 101(1): 165 - 173. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. C. F. Proctor, R. Ligrone, J. G. Duckett, M. C. F. Proctor, R. Ligrone, and J. G. Duckett Desiccation Tolerance in the Moss Polytrichum formosum: Physiological and Fine-structural Changes during Desiccation and Recovery Ann. Bot., June 1, 2007; 99(6): 1243 - 1243. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. C. F. Proctor, R. Ligrone, and J. G. Duckett Desiccation Tolerance in the Moss Polytrichum formosum: Physiological and Fine-structural Changes during Desiccation and Recovery Ann. Bot., January 1, 2007; 99(1): 75 - 93. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. PRESSEL, R. LIGRONE, and J. G. DUCKETT Effects of De- and Rehydration on Food-conducting Cells in the Moss Polytrichum formosum: A Cytological Study Ann. Bot., July 1, 2006; 98(1): 67 - 76. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. Alpert Constraints of tolerance: why are desiccation-tolerant organisms so small or rare? J. Exp. Biol., May 1, 2006; 209(9): 1575 - 1584. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. Bartels Desiccation Tolerance Studied in the Resurrection Plant Craterostigma plantagineum Integr. Comp. Biol., November 1, 2005; 45(5): 696 - 701. [Abstract] [Full Text] [PDF]
|
|