Photosynthetic limitation and mechanisms of photoprotection under drought and recovery of Calotropis procera, an evergreen C3 from arid regions
| Autor: | Silvia Pereira, Ana Maria Benko-Iseppon, Diego Gomes Ramos, Rebeca Rivas, Gabriella Frosi, Mauro Santos |
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| Rok vydání: | 2017 |
| Předmět: |
0106 biological sciences
0301 basic medicine Physiology AMAX fungi Drought tolerance RuBisCO food and beverages Plant Science Biology Evergreen biology.organism_classification Photosynthesis 01 natural sciences 03 medical and health sciences 030104 developmental biology Calotropis procera Photoprotection Botany Genetics biology.protein Photorespiration 010606 plant biology & botany |
| Zdroj: | Plant Physiology and Biochemistry. 118:589-599 |
| ISSN: | 0981-9428 |
| Popis: | Calotropis procera is a C3 plant native from arid environmental zones. It is an evergreen, shrubby, non-woody plant with intense photosynthetic metabolism during the dry season. We measured photosynthetic parameters and leaf biochemical traits, such as gas exchange, photochemical parameters, A/Ci analysis, organic solutes, and antioxidant enzymes under controlled conditions in potted plants during drought stress, and following recovery conditions to obtain a better insight in the drought stress responses of C. procera. Indeed, different processes contribute to the drought stress resilience of C. procera and to the fast recovery after rehydration. The parameters analyzed showed that C. procera has a high efficiency for energy dissipation. The photosynthetic machinery is protected by a robust antioxidant system and photoprotective mechanisms such as alternative pathways for electrons (photorespiration and day respiration). Under severe drought stress, increased stomatal limitation and decreased biochemical limitation permitted C. procera to maintain maximum rate of Rubisco carboxylation (Vc,max) and photosynthetic rate (Amax). On the other hand, limitation of stomatal or mesophyll CO2 diffusion did not impair fast recovery, maintaining Vc,max, chloroplast CO2 concentration (Cc) and mesophyll conductance (gm) unchanged while electron flow used for RuBP carboxylation (Jc) and Amax increased. The ability to tolerate drought stress and the fast recovery of this evergreen C3 species was also due to leaf anti-oxidative stress enzyme activity, and photosynthetic pigments. Thus, these different drought tolerance mechanisms allowed high performance of photosynthetic metabolism by drought stressed plants during the re-watering period. |
| Databáze: | OpenAIRE |
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