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Arabidopsis poly(A) polymerase PAPS 1 limits founder‐cell recruitment to organ primordia and suppresses the salicylic acid‐independent immune response downstream of EDS 1/ PAD 4
Author(s) -
Trost Gerda,
Vi Son Lang,
Czesnick Hjördis,
Lange Peggy,
Holton Nick,
Giavalisco Patrick,
Zipfel Cyril,
Kappel Christian,
Lenhard Michael
Publication year - 2014
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/tpj.12421
Subject(s) - biology , primordium , microbiology and biotechnology , arabidopsis , gene isoform , polyadenylation , arabidopsis thaliana , immune system , mutant , gene , genetics , messenger rna
Summary Polyadenylation of pre‐ mRNA s by poly(A) polymerase ( PAPS ) is a critical process in eukaryotic gene expression. As found in vertebrates, plant genomes encode several isoforms of canonical nuclear PAPS enzymes. In Arabidopsis thaliana these isoforms are functionally specialized, with PAPS1 affecting both organ growth and immune response, at least in part by the preferential polyadenylation of subsets of pre‐ mRNA s. Here, we demonstrate that the opposite effects of PAPS1 on leaf and flower growth reflect the different identities of these organs, and identify a role for PAPS1 in the elusive connection between organ identity and growth patterns. The overgrowth of paps1 mutant petals is due to increased recruitment of founder cells into early organ primordia, and suggests that PAPS1 activity plays unique roles in influencing organ growth. By contrast, the leaf phenotype of paps1 mutants is dominated by a constitutive immune response that leads to increased resistance to the biotrophic oomycete Hyaloperonospora arabidopsidis and reflects activation of the salicylic acid‐independent signalling pathway downstream of ENHANCED DISEASE SUSCEPTIBILITY1 (EDS1)/PHYTOALEXIN DEFICIENT4 (PAD4). These findings provide an insight into the developmental and physiological basis of the functional specialization amongst plant PAPS isoforms.