GREENER

Genetic control of plant senescence, growth and shade avoidance by the REVOLUTA and WRKY network

01/09/2015 to 31/08/2017

Senescence aiming at recycling and reallocation of nutrients is mediated by a higly regulated genetic program
and determined by development and environmental factors. Premature senescence induced under stress, such as shade, lead to a large decrease in plant performance. Several lines of evidence suggest that delaying senescence leads to a better shade avoidance and productivity, but “stay-green” phenotype effects on growth trajectory and shade tolerance remains unclear. Amongst the “stay-green” genes, the WRKY53 transcription factor, has been shown to play a central role in the molecular control of age-induced leaf senescence. Recently, REVOLUTA (REV), a transcription factor known to promote growth under shade condition, has been identified as direct and positive regulator of WRKY53 expression. Previous studies showed that REV likely engages in different protein complexes to regulate the WRKY53 expression, through a tightly controlled homo- or heterodimerization. The WRKY53 pathway mediated by REV could act as a main part in the regulation of plant shade avoidance through senescence processes. This project aims at elucidating the molecular mechanisms by which REV controls WRKY53 expression and contributes to the regulation of the timing of senescence in relation with plant growth and shade avoidance. Particular emphasis will be placed on identifying the interacting partners involved in the regulation of WRKY53 expression by the REV transcription factor. Growth, development and
shade avoidance syndromes will be dissected in detail during Arabidopsis life cycle. Hence, I am proposing to
elucidate the regulation of a major physiological process with a multidisciplinary approach, bridging the gap
between the field of genetics, ecophysiology and ecology. This project will have a great potential to increase our
understanding of the control of leaf senescence and will aid the development of crops with efficient delayed
senescence.