Maize aquaporins transcriptional regulation: cis- and trans-eQTLs.

LAURIE MASTRIAUX; LINDA JEANGUENIN; SANTIAGO ALVAREZ PRADO; CLAUDE WELCKER; FRANÇOIS TARDIEU; FRANÇOIS CHAUMONT

Congreso; Plant Biology 2017; 2017

Plasma membrane intrinsic proteins (PIPs) areaquaporins that facilitate the passive movement of water through biologicalmembranes. These membranous channels are known to be involved innumerous physiological and cellular processes such as hydraulic conductivity,transpiration, photosynthesis and osmoregulation in plants. In a context ofclimatic changes, these proteins could turn out to be key targets for selectionof plant crops varieties optimized for water use efficiency.Whereas ZmPIPmRNA levels in maize tissues have been shown to vary according to thedifferent developmental stages and under varying environmental conditions, themolecular actors and mechanisms regulating the transcription of these genesremain largely unknown. Relying on the genetic material (256 maize genotypesand 800k SNPs collection) and expertise of the European DROPS (DROught tolerantyielding PlantS) project, we are currently performing GWAS analyses in order toidentify promising eQTLs involved in ZmPIPgene regulation in the mature and the elongation zones of the leaf. We arefocusing on five ZmPIP genes (PIP1;1, PIP1;3, PIP2;1, PIP2;2 and PIP2;5), whose expression profiles were the most variable amonggenotypes in preliminary experiments. ZmPIPmRNA levels were measured by RT-qPCR (reverse transcriptase ? quantitativepolymerase chain reaction). GWAS analyses allowed the identification of highlysignificant cis-eQTLs in most cases,as well as promising potential zone-specific trans-eQTL deserving further investigation.