Desiccation rate affects chlorophyll and carotenoid content and the recovery of the aquatic moss Fontinalis antipyretica (Fontinalaceae)

• Published in: Hattoria Vol. 10; pp. 53 - 60
• Main Authors: CARVALHO, Ricardo CRUZ DE, BRANQUINHO, Cristina, SILVA, Jorge MARQUES DA
• Format: Journal Article
• Language: English
• Published: Hattori Botanical Laboratory 2019
• ISSN: 2185-8241; 2423-8961
• DOI: 10.18968/hattoria.10.0_53

  In the Mediterranean climate, during the hot and dry summer, small streams dry out exposing the aquatic bryophyte Fontinalis antipyretica L. ex Hedw. to desiccation, losing all cellular water content. Previous works showed that fast dehydration (less than two hours) is extremely severe, unabling recovery upon rehydration. On the other hand, slow dehydration allows the recovery of the bryophyte through induction of desiccation tolerance mechanisms. To explore how the photosynthetic apparatus responds to contrasting dehydration rates, we measured the chlorophyll a fluorescence parameter Fv/Fm (maximum potential quantum efficiency of Photosystem II) as a proxy to photosynthetic fitness and analysed the content of the pigments (chlorophylls and carotenoids). In slowly dehydrated Fontinalis antipyretica, the content of the pigments remained constant down to RWC of 40–50%, while the loss was striking in fast dehydrated samples as early as RWC of 70–80% RWC, showing different threshold values for different desiccation rates.