The role of peltate scales in desiccation tolerance of Pleopeltis polypodioides
- 869 Downloads
The extreme drought tolerance of the resurrection fern is in part the result of the dorsal scales that assist in water distribution and controlled desiccation.
We studied the effect of peltate scales on water uptake and loss of the desiccation-tolerant epiphytic fern Pleopeltis polypodioides using optical and FTIR microscopy and staining with calcofluor, solophenyl flavine7GFE, and Ruthenium Red. We provide information on structure, property, and function of the scales by measuring water uptake and dehydration, contact angles, and metabolic activity. Peltate scales mainly contain cellulose, xylogalactans, and pectin. Water is absorbed from the center of scales, and the overlapping arrangement of scales facilitates surface spreading of water. Intact fronds hydrated fully within 5 h of imbibition of the apical pinna, without scales water uptake stopped after 1 h. Hydration rates via rhizomes followed a longer time course but also improved in the presence of scales. Fronds with and without scales lost half of their water content in 15 or 4 h, respectively. The overall metabolism of rapidly dehydrated fronds was significantly reduced compared with slowly dehydrated fronds. Thus, water management and metabolism of Pleopeltis are dependent on surface properties determined by peltate scales.
KeywordsResurrection fern Water uptake Dehydration FTIR microscopy Metabolism
Fourier transform infrared spectroscopy
We thank Dr. T. Pesacreta for providing solophenyl flavine 7GFE 500 and Dr. O. Kizilkaya for his help with FTIR spectroscopy. This research was partially supported by NASA grants NNX10AP91G and NNX13AN05A.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
Online Resource Video S1 Spreading of calcofluor solution on the dorsal surface of P. polypodioides. During the first 30 min of imbibition, the dye spreads from the apical pinnae towards rachis and the stipe. During the course of spreading, the dye strongly bounds to the peltate scales. Images were taken at 1 min intervals for 30 min (MP4 2471 kb)
Online Resource Video S2 Uptake of water through the central disc of the scale. Images were taken at 2 s intervals (MP4 960 kb)
Online Resource Video S3 Water movement underneath the scales and uptake via stalk of scale. Images that were taken at 2 s intervals (MP4 1129 kb)
- Benzing D (1976) Bromeliad trichomes: structure, function, and ecological significance. Selbyana 1:330–348Google Scholar
- Fernández V, Sancho-Knapik D, Paula Guzmán, Javier Peguero-Pina J, Gil L, Karabourniotis G, Khayet M, Fasseas C, Alejandro Heredia-Guerrero J, Antonio Heredia, Eustaquio G-P (2014) Wettability, polarity, and water absorption of holm oak leaves: effect of leaf side and age. Plant Physiol 166:168–180CrossRefPubMedCentralPubMedGoogle Scholar
- Haberlandt G (1914) The dermal system in physiological plant anatomy. MacMillan, LondonGoogle Scholar
- Kappen L, Valladares F (2007) Opportunistic growth and desiccation tolerance: the ecological success of poikilohydrous autotrophs. In: Pugnaire F, Valladares F (eds) Handbook of functional plant ecology. Marcel Dekker, New York, pp 10–80Google Scholar
- McCleery E (1907) Stellate hairs and peltate scales of Ohio plants. Ohio Nat 7:51–56Google Scholar
- Müller L, Starnecker G, Winkler S (1981a) A contribution to the ecology of epiphytic ferns from southern Brazil. I. Water absorbing trichomes. Flora 171:55–63Google Scholar
- Müller L, Starnecker G, Winkler S (1981b) Zur Ökologie epiphytischer Farne in Südbrasilien—I. Saugschuppen. Flora 171:55–63Google Scholar
- Rundel P (1982) Water uptake by organs other than roots. In: Lange O, Nobel P, Osmond C (eds) Encyclopedia of plant physiology. Springer, Berlin, pp 111–134Google Scholar
- Schönherr J (2006) Characterization of aqueous pores in plant cuticles and permeation of ionic solutes. J Exp Biol 57:2471–2491Google Scholar
- Zenkteler E, Jędrzejczyk I (2012) Morphology and anatomy of the rhizome of Polypodium × mantoniae Rothm. In: Gola E, Szczęśniak E (eds) Genus Polypodium L. in Poland. Polish Botanical Society, Wroclaw, pp 27–38Google Scholar