title: Dehydration protection provided by a maternal cuticle improves offspring fitness in the moss Funaria hygrometrica.
abstract: OBJECTIVE
  In bryophytes the sporophyte offspring are in contact with, nourished from, and partially surrounded by the maternal gametophyte throughout their lifespan. During early development, the moss sporophyte is covered by the calyptra, a cap of maternal gametophyte tissue that has a multilayered cuticle. In this study the effects on sporophyte offspring fitness of removing the maternal calyptra cuticle, in combination with dehydration stress, is experimentally determined.
  
  
  METHODS
  Using the moss Funaria hygrometrica, calyptra cuticle waxes were removed by chemical extraction and individuals were exposed to a short-term dehydration event. Sporophytes were returned to high humidity to complete development and then aspects of sporophyte survival, development, functional morphology, and reproductive output were measured.
  
  
  RESULTS
  It was found that removal of calyptra cuticle under low humidity results in significant negative impacts to moss sporophyte fitness, resulting in decreased survival, increased tissue damage, incomplete sporophyte development, more peristome malformations, and decreased reproductive output.
  
  
  CONCLUSIONS
  This study represents the strongest evidence to date that the structure of the calyptra cuticle functions in dehydration protection of the immature moss sporophyte. The investment in a maternal calyptra with a multilayered cuticle increases offspring fitness and provides a functional explanation for calyptra retention across mosses. The moss calyptra may represent the earliest occurance of maternal protection via structural provisioning of a cuticle in green plants.
authors.affiliation: University of Connecticut, Department of Ecology and Evolutionary Biology, 75 North Eagleville Road, U-3043, Storrs, CT 06269, USA. jessica.m.budke@gmail.com
authors.forename: Jessica M
authors.initials: JM
authors.lastname: Budke
authors.forename: Bernard
authors.initials: B
authors.lastname: Goffinet
authors.forename: Cynthia S
authors.initials: CS
authors.lastname: Jones
mesh_terms: D019068:Bryopsida / Q000254:growth & development / Q000502:physiology* / Q000648:ultrastructure; D003681:Dehydration; D055993:Germ Cells, Plant / Q000166:cytology / Q000254:growth & development / Q000648:ultrastructure; D019441:Plant Epidermis / Q000166:cytology / Q000502:physiology*; D012098:Reproduction