The mitocondrial ferredoxin ADXR is crucial for normal development and fertilization of the female gametophyte in Arabidopsis thaliana

ANDRES M. BELLIDO; AYELEN M. DISTÉFANO; EDUARDO J. ZABALETA; GABRIELA C. PAGNUSSAT

Rosario

Congreso; ICPMB 8th International Conference for Plant Mitochondrial Biology; 2013

ICPMB

In Arabidopsis, the female gametophyte or embryo sac is a highly polarized structure composed by seven cells: two gametic cells, the egg cell and the central cell, and five accessory cells: two synergids and three antipodal cells. We here show the study of an Arabidopsis mutant with an insertion in ADXR a nuclear gene encoding for a mitochondrial adrenodoxin-like ferrodoxin. The silique analysis of heterozygous plants ADXR/adxr, determined a percentage of abortion of 38,4%, indicating that the insertion is affecting the gametophyte development or function. Reciprocal crossings show that transmission trough the female gametophyte is severely compromised. DIC microscopy studies revealed that mutants embryo sac are able to reach maturity but showed alterations in the attraction of pollen tubes, suggesting that communication between the female and the male gametophytes is impaired in the mutants. Intracellular localization of ADXR during the female gametophyte development is also presented by the use of translational fusions with GFP-GUS. Additionally, the identity of all cells inside adxr embryo sacs was analyzed by the use of cell specific markers for egg cell, central cell, antipodal and synergid cells