Freezing resistance in Patagonian woody shrubs: the role of cell wall elasticity and stem vessel size

Authors
Zhang, Yong Jiang; Bucci, Sandra Janet; Arias, Nadia Soledad; Scholz, Fabian Gustavo; Hao, Guang You; Cao, Kun Fang; Goldstein, Guillermo Hernan
Publication Year
2016
Language
English
Format
article
Status
Published version
Description
Freezing resistance through avoidance or tolerance of extracellular ice nucleation is important for plant survival in habitats with frequent subzero temperatures. However, the role of cell walls in leaf freezing resistance and the coordination between leaf and stem physiological processes under subzero temperatures are not well understood. We studied leaf and stem responses to freezing temperatures, leaf and stem supercooling, leaf bulk elastic modulus and stem xylem vessel size of six Patagonian shrub species from two sites (plateau and low elevation sites) with different elevation and minimum temperatures. Ice seeding was initiated in the stem and quickly spread to leaves, but two species from the plateau site had barriers against rapid spread of ice. Shrubs with xylem vessels smaller in diameter had greater stem supercooling capacity, i.e., ice nucleated at lower subzero temperatures. Only one species with the lowest ice nucleation temperature among all species studied exhibited freezing avoidance by substantial supercooling, while the rest were able to tolerate extracellular freezing from −11.3 to −20 °C. Leaves of species with more rigid cell walls (higher bulk elastic modulus) could survive freezing to lower subzero temperatures, suggesting that rigid cell walls potentially reduce the degree of physical injury to cell membranes during the extracellular freezing and/or thaw processes. In conclusion, our results reveal the temporal–spatial ice spreading pattern (from stem to leaves) in Patagonian shrubs, and indicate the role of xylem vessel size in determining supercooling capacity and the role of cell wall elasticity in determining leaf tolerance of extracellular ice formation.
Fil: Zhang, Yong Jiang. Chinese Academy of Sciences; República de China. Harvard University; Estados Unidos
Fil: Bucci, Sandra Janet. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de la Patagonia ; Argentina
Fil: Arias, Nadia Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de la Patagonia ; Argentina
Fil: Scholz, Fabian Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de la Patagonia ; Argentina
Fil: Hao, Guang You. Chinese Academy of Sciences; República de China
Fil: Cao, Kun Fang. Guangxi University; China
Fil: Goldstein, Guillermo Hernan. University of Miami; Estados Unidos. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina
Subject
BULK ELASTIC MODULUS
PATAGONIAN STEPPE
LEAF LETHAL TEMPERATURE
SUPERCOOLING
Otras Ciencias Biológicas
Ciencias Biológicas
CIENCIAS NATURALES Y EXACTAS
Access level
Restricted access
License
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
Repository
CONICET Digital (CONICET)
Institution
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identifier
oai:ri.conicet.gov.ar:11336/46053