Female gametogénesis requires mitochondrial ferredoxins in Arabidopsis

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

Mar del Plata

Congreso; Reunion Anual de la Sociedad Argentina de Investigaciones en Bioquimica y Biología Molecular; 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. Here, we 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 abortions and reciprocal crossings showed that transmission trough the FG is compromised. DIC studies revealed adxr mutants with abnormal FGs. The study of cell identity by using the expression of specific markers indicated that all cells are specified in those embryo sacs that are able to reach maturity. However, aniline blue staining showed abnormal growing patterns of pollen tubes (PTs), including PTs invading embryo sacs and the attraction of two PTs, which suggests a communication problem between the male and the female gametophytes. The expression pattern of ADXR was only detected inside the FG in the ovule. Furthermore, expression was also detected in leaves, sepals and stomata. Plants carrying artificial miRNAs (amiRs) targeting ADXR, ADX1 and ADX2 are under study to know if these three genes have sporophytic functions.