Gamete expression of TALE class HD genes activates the diploid sporophyte program in Marchantia polymorpha

eLife

Felix Althoff¹  Sabine Zachgo¹  John L Bowman²  Eduardo Flores-Sandoval²  Madlen I Rast-Somssich²  Tom Dierschke³ 

[1] Botany Department, University of Osnabrück, Osnabrück, Germany;School of Biological Sciences, Monash University, Melbourne, Australia;School of Biological Sciences, Monash University, Melbourne, Australia;Botany Department, University of Osnabrück, Osnabrück, Germany;

关键词: TALE-homeodomain;    plant evolution;    Marchantia;    alternation of generations;    Other;   

DOI  :  10.7554/eLife.57088

来源: eLife Sciences Publications, Ltd

【 摘 要 】

Eukaryotic life cycles alternate between haploid and diploid phases and in phylogenetically diverse unicellular eukaryotes, expression of paralogous homeodomain genes in gametes primes the haploid-to-diploid transition. In the unicellular chlorophyte alga Chlamydomonas, KNOX and BELL TALE-homeodomain genes mediate this transition. We demonstrate that in the liverwort Marchantia polymorpha, paternal (sperm) expression of three of five phylogenetically diverse BELL genes, MpBELL234, and maternal (egg) expression of both MpKNOX1 and MpBELL34 mediate the haploid-to-diploid transition. Loss-of-function alleles of MpKNOX1 result in zygotic arrest, whereas a loss of either maternal or paternal MpBELL234 results in variable zygotic and early embryonic arrest. Expression of MpKNOX1 and MpBELL34 during diploid sporophyte development is consistent with a later role for these genes in patterning the sporophyte. These results indicate that the ancestral mechanism to activate diploid gene expression was retained in early diverging land plants and subsequently co-opted during evolution of the diploid sporophyte body.

【 授权许可】

CC BY