Mitochondrial ferredoxins are essential for gametophyte development in Arabidopsis thaliana

BELLIDO, ANDRÉS MARTÍN; DISTÉFANO, AYELÉN MARIANA; ZABALETA, EDUARDO JULIÁN; PAGNUSSAT, GABRIELA CAROLINA

Iguazú Falls

Congreso; International Plant Molecular Biology Congress IPMB; 2015

In Arabidopsis, the female gametophyte (FG) is a polarized structure composed by seven cells: the egg cell, the central cell, two synergids and three antipodal cells. We here show the study of Arabidopsis mutants with insertions in nuclear genes encoding for mitochondrial ferredoxins and a ferredoxin reductase (ADX and ADXR respectively). Siliques of +/adxr heterozygous plants presented around 30% of abortions and reciprocal crossings showed that transmission trough the FG is compromised. DIC studies revealed adxr mutants with abnormal FG and embryos that are not able to reach complete maturation. The identity of all cells inside adxr embryo sacs was analyzed by studying the expression of cell specific markers for egg cell, central cell, antipodal and synergid cells. Pollination with marker pLAT52-RFP line as a pollen donor and aniline blue staining assays, showed abnormal growing patterns of pollen tubes (PT), including invading embryo sacs and attraction of two PT, which suggest a communication problem between the male and the female gametophytes. The expression pattern of ADXR indicates that its expression is specific for the gametophytic cells of the ovules. Furthermore, expression is also detected in leaves, sepals and stomata indicating that ADXR might have sporophytic functions as well.