Plant Diversity ›› 2014, Vol. 36 ›› Issue (06): 683-697.doi: 10.7677/ynzwyj201414047

• Articles •     Next Articles

Adaptation to Extremely High Temperature in an Alpine Environment: Systemic Thermotolerance in Arabis paniculata

 TANG  Ting-1、2, ZHENG  Guo-Wei-1, LI  Wei-Qi-1   

  1. 1 Germplasm Bank of Wild Species in Southwest China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China; 2 University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2014-03-18 Online:2014-11-25 Published:2014-06-11
  • Supported by:

    NSFC (31300251) and XiBuZhiGuang Project

Abstract:

Alpine ecosystems are characterised by frequent fluctuations between high and low temperatures. The resistance of alpine plants to low temperatures has received considerable attention, but little is known about their adaptation to extremely high temperatures (>45℃). In this study, the alpine species Arabis paniculata was shown to display superior basal thermotolerance and acquired thermotolerance than its relative Arabidopsis thaliana. Our chlorophyll fluorescence data suggest that under heat shock conditions, Apaniculata has a thermostable photosystem II (PSII) and that efficient nonphotochemical quenching maintains a high level of photosynthetic efficiency. Assays of ion leakage and malondialdehyde (MDA) content revealed that membrane damage caused by high temperatures was less severe in Apaniculata than in Athaliana. The degree of unsaturation and fatty acid chain length was closely correlated with membrane fluidity. Compared with Athaliana, Apaniculata had a lower 16∶3 (roughanic acid) content, longer fatty acid chain length and no major alterations in the level of unsaturation of membrane fatty acids; this might enable the maintenance of stable membrane fluidity. Furthermore, more extensive accumulation of heat shock proteins (HSPs), such as HSP101 and HSP70 in Apaniculata compared with Athaliana, might correlate with better protection against high temperature in Apaniculata than in Athaliana. Our findings suggest that the alpine plant Apaniculata uses all of these physiological and biochemical adjustments to adapt to high temperature, and that similar to lowland tropical species, Apaniculata exhibits systemic thermotolerance. Accordingly, Apaniculata might be a useful model plant to study the molecular and physiological mechanisms that contribute to thermotolerance in plants.

Key words: Alpine plants, Arabis paniculata, Thermotolerance, Photosystem, Fatty acids, Heat shock proteins

CLC Number: 

  • Q 945