Arabidopsis Cuticle Control Genes are Downregulated upon Submergence while Genetic Manipulation of Arabidopsis to Decreased Cuticle Thickness Exhibits Minimal Effect on Plant Fitness in Flooded Conditions

Abstract

Flooding costs agricultural producers worldwide billions in lost crop yield each year and with rising temperatures flooding events are expected to increase. The cuticle, as the primary barrier between the plant and its external environment is crucial to its survival and adaption when the environment is changed from air to water. It has been shown that plants which live in more frequently flooded areas typically have thinner cuticles and may exhibit gas films based on cuticle properties. This study aimed to evaluate the effects of cuticle properties on plant survival for the sake of improving plant flooding tolerance by understanding the role and regulation of the cuticle under submergence. The lines cuticle destructing factor 1 overexpressor (CDEF1OX) and ECERFERIUM 1 (cer1) with thinned cuticles relative to wild type were not found to show any fitness advantage under submergence over wild type. Analysis of cuticle regulation in plants with disrupted hypoxia sensing demonstrated no direct connection between hypoxia sensing and the submergence response but did show some correlation between plant energy status and changes in cuticle regulation. Additionally, this study found that Arabidopsis traps air near its central rosette in a gas film but failed to demonstrate if this gas film gave a survival advantage. Altogether, the findings of the study indicate that the advantage of a thinner cuticle and the presence of a gas film are not significant enough to affect Arabidopsis survival in short term submergence in the dark alone but demonstrates the cuticle is still actively regulated during submergence.