An Omics approach on Marchantia polymorpha single FERONIA and MARIS homologs confirms links between cell wall integrity and abscisic acid
Plant cells are surrounded by an extracellular cell wall that shields them from their abiotic and biotic environment. To coordinate their growth with their cell wall status, they have developed cell wall integrity mechanisms at the center of which lies the transmembrane Malectin-like receptor kinase FERONIA (FER). FER controls a myriad of plant developmental processes including sexual reproduction, cell growth and morphogenesis, often intersecting with phytohormones-dependent pathways such as abscisic acid (ABA) or plant immunity. Interestingly, FER and its downstream receptor-like cytoplasmic kinase MARIS (MRI) were shown to cooperate similarly in the control of root hair and rhizoid integrity for the vascular model Arabidopsis and the early diverging bryophyte model Marchantia polymorpha, respectively. Here, we carried out comparative transcriptomics and proteomics approach on Mpfer-1 and Mpmri-1 knock-down mutant plants and the wild-type strains Tak-1 and Tak-2. Our -omics analyses revealed that globally, MpFER and MpMRI largely cooperate to negatively regulate transcriptional and translational networks in particular those related to plant defense and ABA responses. Moreover, Mpfer-1 plants were found to be hypersensitive to ABA-dependent growth inhibition indicating that FER's function of negatively regulating ABA-related growth responses is conserved between bryophytes and vascular plants. Overall design: To reveal pathways that could be regulated by the ancestral MpFER/MpMRI module or alternative compensatory ones that are up-regulated in the absence of the module in Marchantia, comparative transcriptomic (RNA-seq)  analyses of Mpfer-1 (male) and Mpmri-1 (female) lines with short bursting rhizoids and their respective wild-type male (Tak-1) and female (Tak-2) strains with intact rhizoids were carried out. For this purpose, 3-week-old Marchantia thalli grown on cellophane membranes were collected and RNA were extracted and submited to RNAseq.