High-temperature sensitivity and its acclimation for photosynthetic electron reactions of desert succulents

Journal Article · Sat Aug 01 00:00:00 EDT 1987 · Plant Physiology; (USA)

DOI:https://doi.org/10.1104/pp.84.4.1063· OSTI ID:6867380

Chetti, M B; Nobel, P S ^[1]

---

1. Univ. of California, Los Angeles (USA)

Photosynthetic electron reactions of succulent plants from hot deserts are able to tolerate extremely high temperatures and to acclimate to seasonal increase in temperature. In this study, we report the influence of relatively long, in vivo, high-temperature treatments on electron transport reactions for two desert succulents, Agave deserti and Opuntia ficus-indica, species which can tolerate 60{degree}C. Whole chain electron transport averaged 3{degree}C more sensitive to a 1-hour high-temperature treatment than did PSII (Photosystem II) which in turn averaged 3{degree}C more sensitive than did PSI. For plants maintained at day/night air temperatures of 30{degree}C/20{degree}C, treatment at 50{degree}C cause these reactions to be inhibited an average of 39% during the first hour, an additional 31% during the next 4 hours, and 100% by 12 hours. Upon shifting the plants from 30{degree}C/20{degree}C to 45{degree}C/35{degree}C, the high temperatures where activity was inhibited 50% increased 3{degree}C to 8{degree}C for the three electron transport reactions, the half-times for acclimation averaging 5 days for A. deserti and 4 days for O. ficus-indica. For the 45{degree}C/35{degree}C plants treated at 60{degree}C for 1 hour, PSI activity was reduced by 54% for A. deserti and 36% for O. ficus-indica. Acclimation leads to a toleration of very high temperatures without substantial disruption of electron transport for these desert succulents, facilitating their survival in hot deserts. Indeed, the electron transport reactions of these species tolerate longer periods at higher temperatures than any other vascular plants so far reported.

• DOE Contract Number: AC03-76SF00012
• OSTI ID: 6867380
• Journal Information: Plant Physiology; (USA), Vol. 84:4; ISSN 0032-0889
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
CACTI
TEMPERATURE EFFECTS
PHOTOSYNTHESIS
PHOTOSYNTHETIC REACTION CENTERS
PLANT GROWTH
SENSITIVITY
TOLERANCE
CHEMICAL REACTIONS
GROWTH
MAGNOLIOPHYTA
MAGNOLIOPSIDA
PHOTOCHEMICAL REACTIONS
PLANTS
SYNTHESIS
560200* - Thermal Effects