The MED30 sub 1 unit of Mediator Complex is essential for early plant 2 development and promotes flowering in Arabidopsis thaliana

IÑIGO, S; DIEGO F. FIOL; HERNÁN LORENZI; PABLO DIEGO CERD�N; ARELLANO, SOFÍA MAITE; ANA R SEDE; JORGE PROMETEO MUSCHIETTI; AIMÉ JASKOLOWSKI; LEONARDO A ARIAS; OLDRA, MARÍA BELÉN; GABRIELA C PAGNUSSAT

DEVELOPMENT

COMPANY OF BIOLOGISTS LTD

Lugar: Cambridge; Año: 2019 vol. 146 p. 1 - 7

0950-1991

Mediator is a large multiprotein complex that is virtually required for the28 transcription of most, if not all, genes transcribed by RNA Polymerase II. A core set 29 of subunits are essential to assemble a functional Mediator in vitro and therefore 30 the corresponding loss of function mutants are expected to be lethal. The MED30 31 subunit is essential in animal systems, but it is absent in yeast. Here we report that 32 MED30 is essential for both male gametophyte and embryo development in the 33 model plant Arabidopsis thaliana. Mutant med30 pollen grains are viable and some 34 of them can germinate and target the ovules, but embryos abort shortly after 35 fertilization, suggesting that MED30 is important for the paternal control of early 36 embryo development. If gametophyte defects are bypassed by specific pollen 37 complementation, loss of MED30 leads to early embryo development arrest. Later38 in plant development, MED30 promotes flowering through multiple signaling39 pathways; its downregulation leads to a phase change delay, downregulation of40 SPL3, FT and SOC1, and upregulation of FLC.