Elevation of night-time temperature increases terpenoid emissions from Betula pendula and Populus tremula.

Volatile organic compounds (VOCs) are expected to have an important role in plant adaptation to high temperatures. The impacts of increasing night-time temperature on daytime terpenoid emissions and related gene expression in silver birch (Betula pendula) and European aspen (Populus tremula) clones were studied. The plants were grown under five different night-time temperatures (6, 10, 14, 18, and 22 degrees C) while daytime temperature was kept at a constant 22 degrees C.

Birch PR-10c is induced by factors causing oxidative stress but appears not to confer tolerance to these agents.

•  Expression of all known and newly found pathogenesis-related PR-10 proteins (PR-10a, b, c, d, e) was analysed from Cu-sensitive and -tolerant birch clones to find out whether they follow the same expression pattern. The relationship of PR-10 proteins, particularly PR-10c, to oxidative stress caused by metals or ozone was studied in tolerant and sensitive birch clones to find out possible linkages to tolerance. •  Antibody developed to PR-10c was used in Western blot analysis.