Rapid heating of intact leaves reveals initial effects of stromal oxidation on photosynthesis

被引：27

作者：

Schrader, Stephen M. ^{[1
]}

Kleinbeck, Kyle R. ^{[1
]}

Sharkey, Thomas D. ^{[1
]}

机构：

[1] Univ Wisconsin, Dept Bot, Madison, WI 53706 USA

来源：

PLANT CELL AND ENVIRONMENT | 2007年 / 30卷 / 06期

关键词：

heat fleck; high temperature stress; redox regulation; Rubisco; thylakoid; ELECTRON-TRANSPORT CHAIN; RUBISCO ACTIVASE ISOFORM; HIGH-TEMPERATURE; GAS-EXCHANGE; RIBULOSE-1,5-BISPHOSPHATE CARBOXYLASE/OXYGENASE; SPINACH LEAVES; PIMA COTTON; LIGHT; STRESS; REDUCTION;

D O I：

10.1111/j.1365-3040.2007.01657.x

中图分类号：

Q94 [植物学];

学科分类号：

071001 ;

摘要：

Heat stress in leaves under natural conditions is characterized by rapid fluctuations in temperature. These fluctuations can be on the order of 10 degrees C in 7 s. By using a specially modified gas-exchange chamber, these conditions were mimicked in the laboratory to analyse the biochemical response to heat spikes. The decline in ribulose 1.5-bisphosphate carboxylase/oxygenase (Rubisco) activity during prolonged heat stress is generally associated with an increase in ribulose 1,5-bisphosphate (RuBP) levels. However, rapid heating caused an initial decline in RuBP which was subsequently followed by a small decline in Rubisco carbamylation. The ratio of RuBP to Rubisco sites declined from a saturating concentration to a sub-saturating concentration, providing a possible mechanism for the decarbamylation of Rubisco. If RuBP is saturating (> 1.8 RuBP Rubisco site(-1)), it acts as a cap on the catalytic site and keeps Rubisco activated. Measurements of triose-phosphate levels and NADP-malate dehydrogenase activation (a stromal redox proxy) indicated that the regeneration of RuBP by the Calvin cycle was limited by the availability of redox power.

引用

页码：671 / 678

页数：8

共 45 条

[1] THE RELATIONSHIP BETWEEN STEADY-STATE GAS-EXCHANGE OF BEAN-LEAVES AND THE LEVELS OF CARBON-REDUCTION-CYCLE INTERMEDIATES [J].