Plant shade response: have the aquaporins some role in this response?

MILENA MANZUR; MOIRA SUTKA; GABRIELA AMODEO; ROMINA SELLARO

Foz de Iguazú

Congreso; 11t Inetnational Congress of Plant Molecular Biology; 2015

The shade avoidance syndrome (SAS) is one of the best studied forms of plant phenotypic plasticity. This syndrome involved an extra growth of some parts of plant body (e.g. hypocotyls, leaf petiole). Thus, extra photosynthesis products, nutrients and water availability are necessary for this response. In particular, water channel activity may have a crucial role to satisfy water demand for such extra growth. It is well known that Plasma Intrinsic Proteins (PIP) function as water channels and their activity is affected by several stress conditions. The aim of this work was evaluate is PIP aquaporins are involved in shade avoidance response. For this we analyzed aquaporin gene expression on microarrays of Arabidopsis thaliana under shade effect (i.e. low R/FR ratio), and we also studied shade effect on hypocotyls elongation in aquaporin mutants of A. thaliana. We found that under shade conditions the only PIP aquaporins that were over expressed in the wild type genotype were PIP1;1, PIP1;3, PIP2;1, PIP2;3, PIP2;4, PIP2;6. When analyzing hypocotyls elongation, we found that pip2;2-3, pip2;2-4, pip2;6-1, pip2;6-2 showed lower change in hypocotyl length respect to wild type and pip2;1-1, pip2;1-2 mutants. To our knowledge these are the first evidences that suggest that these PIP2 aquaporins might be involved in plant growth regulation associated to the shade avoidance syndrome.