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Antagonistic control of flowering time by functionally specialized poly(A) polymerases in Arabidopsis thaliana
Author(s) -
Czesnick Hjördis,
Lenhard Michael
Publication year - 2016
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.13280
Subject(s) - biology , polyadenylation , arabidopsis thaliana , mutant , gene isoform , arabidopsis , microbiology and biotechnology , phenotype , genetics , messenger rna , gene
Summary Polyadenylation is a critical 3′‐end processing step during maturation of pre‐ mRNA s, and the length of the poly(A) tail affects mRNA stability, nuclear export and translation efficiency. The Arabidopsis thaliana genome encodes three canonical nuclear poly(A) polymerase ( PAPS ) isoforms fulfilling specialized functions, as reflected by their different mutant phenotypes. While PAPS 1 affects several processes, such as the immune response, organ growth and male gametophyte development, the roles of PAPS 2 and PAPS 4 are largely unknown. Here we demonstrate that PAPS 2 and PAPS 4 promote flowering in a partially redundant manner. The enzymes act antagonistically to PAPS 1, which delays the transition to flowering. The opposite flowering‐time phenotypes in paps1 and paps2 paps4 mutants are at least partly due to decreased or increased FLC activity, respectively. In contrast to paps2 paps4 mutants, plants with increased PAPS 4 activity flower earlier than the wild‐type, concomitant with reduced FLC expression. Double mutant analyses suggest that PAPS 2 and PAPS 4 act independently of the autonomous pathway components FCA , FY and CstF64 . The direct polyadenylation targets of the three PAPS isoforms that mediate their effects on flowering time do not include FLC sense mRNA and remain to be identified. Thus, our results uncover a role for canonical PAPS isoforms in flowering‐time control, raising the possibility that modulating the balance of the isoform activities could be used to fine tune the transition to flowering.