| Title: | Changes in photosynthetic rate and stress volatile emissions through desiccation-rehydration cycles in desiccation-tolerant epiphytic filmy ferns (Hymenophyllaceae) |
| Author(s): | Niinemets U; Bravo LA; Copolovici L; |
| Address: | "Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Kreutzwaldi 1, Tartu, 51014, Estonia. Estonian Academy of Sciences, Kohtu 6, Tallinn, 10130, Estonia. Departamento de Ciencias, Agronomicas y Recursos Naturales, Facultad de Ciencias Agropecuarias y Forestales, and Center of Plant, Soil Interaction and Natural Resources Biotechnology, Scientific and Technological Bioresource Nucleus, Universidad de La Frontera, Temuco, 1145, Chile. Faculty of Food Engineering, Tourism and Environmental Protection, Institute of Research, Innovation and Development in Technical and Natural Sciences, 'Aurel Vlaicu' University, Romania, 2 Elena Dragoi, Arad, 310330, Romania" |
| ISSN/ISBN: | 1365-3040 (Electronic) 0140-7791 (Print) 0140-7791 (Linking) |
| Abstract: | "Exposure to recurrent desiccation cycles carries a risk of accumulation of reactive oxygen species that can impair leaf physiological activity upon rehydration, but changes in filmy fern stress status through desiccation and rewatering cycles have been poorly studied. We studied foliage photosynthetic rate and volatile marker compounds characterizing cell wall modifications (methanol) and stress development (lipoxygenase [LOX] pathway volatiles and methanol) through desiccation-rewatering cycles in lower-canopy species Hymenoglossum cruentum and Hymenophyllum caudiculatum, lower- to upper-canopy species Hymenophyllum plicatum and upper-canopy species Hymenophyllum dentatum sampled from a common environment and hypothesized that lower canopy species respond more strongly to desiccation and rewatering. In all species, rates of photosynthesis and LOX volatile emission decreased with progression of desiccation, but LOX emission decreased with a slower rate than photosynthesis. Rewatering first led to an emission burst of LOX volatiles followed by methanol, indicating that the oxidative burst was elicited in the symplast and further propagated to cell walls. Changes in LOX emissions were more pronounced in the upper-canopy species that had a greater photosynthetic activity and likely a greater rate of production of photooxidants. We conclude that rewatering induces the most severe stress in filmy ferns, especially in the upper canopy species" |
| Keywords: | Dehydration Ferns/metabolism/*physiology Lipoxygenase/metabolism Metabolic Networks and Pathways Methanol/metabolism *Photosynthesis Respiratory Burst Volatile Organic Compounds/metabolism Water/metabolism Hymenophyllaceae desiccation kinetics emission bu; |
| Notes: | "MedlineNiinemets, Ulo Bravo, Leon A Copolovici, Lucian eng 322603/ERC_/European Research Council/International Research Support, Non-U.S. Gov't 2018/04/01 Plant Cell Environ. 2018 Jul; 41(7):1605-1617. doi: 10.1111/pce.13201. Epub 2018 May 10" |
