Unravelling the impact of UCP1 overexpression in barley and upon stability of Group VII ethylene response factor transcription factors in Arabidopsis

Abstract

The research plan presented in this application is a continuation of the Collaborative Project (BBSRC/EMBRAPA BB/N004523/1). A part of the project was conducted during a BEPE project of the applicant (FAPESP 2015/25881-1). Barley plants were transformed with a construct targeted at overexpression (oe) of Arabidopsis UCP1. In addition, a series of mutants for the N-End Rule pathway were transformed with the Arabidopsis UCP1-oe construct. Homozygous lines for the barley transgenic events were obtained by the Wilson group (UoN). In parallel homozygous lines for Arabidopsis transgenic events were selected in Campinas. These Arabidopsis genetic series and the barley UCP1-oe plants will be used to complete the experiments during the second BEPE.The aim of the project is to examine the mechanism by which UCP1-oe reconfigures cellular metabolism and induces the observed hypoxic response. The data already produced indicates that UCP1-oe triggers hypoxia by altering the N-End Rule pathway . Next steps will include the study of the connection between UCP1 and the N-End Rule pathway during plant development and how this pathway contributes to the stress-response in UCP1-oe phenotypes. We have already shown that UCP1-oe makes tobacco plants more tolerant to multiple stresses and increases yield . Flower development, in particular pollen formation, plays a key role in plant seed production, but is also extremely vulnerable to abiotic stress. We observed that flowers from UCP1-oe lines act as stronger photoassimilate sinks during drought stress, resulting in enhanced drought resilience and increased yield. Nevertheless, we still poorly understand the effect of UCP1 on pollen formation and plant reproduction. This programme of parallel work in Arabidopsis and Barley will allow us to better understand the mechanism by which UCP1-oe produces a string response to abiotic stresses in a model tractable system alongside an important crop.