Effects of moderate heat stress on photosynthesis: importance of thylakoid reactions, rubisco deactivation, reactive oxygen species, and thermotolerance provided by isoprene

ABSTRACT Photosynthesis is particularly sensitive to heat stress and recent results provide important new insights into the mechanisms by which moderate heat stress reduces photosynthetic capacity. Perhaps most surprising is that there is little or no damage to photosystem II as a result of moderate heat stress even though moderate heat stress can reduce the photosynthetic rate to near zero. Moderate heat stress can stimulate dark reduction of plastoquinone and cyclic electron flow in the light. In addition, moderate heat stress may increase thylakoid leakiness. At the same time, rubisco deactivates at moderately high temperature. Relationships between effects of moderate heat on rubisco activation and…

• NS
  National Science Foundation

  Award: 0212204
• UD
  U.S. Department of Agriculture
• CS
  Cooperative State Research, Education, and Extension Service