Characterization of a female gametophytic mutant in Arabidopsis thaliana

IGLESIAS, MJ; TOSSI, V; GERGOFF, G; FANELLO, D; LARRAMBURU, E; GONZALEZ, ME; LOBATO, C; TUROWSKI, V; VILLARREAL, V; GÓMEZ-LOBATO, ME; MITTON, F; MANSILLA, Y; REUTEMANN, A; GONORAZKY, G; PAGNUSSAT, G; ZABALETA, E

San Miguel de Tucumán, Tucumán, Argentina

Congreso; XLV Reunión anual Sociedad argentina de investigación en bioquímica y biología molecular; 2009

Sociedad argentina de investigación en bioquímica y biología molecular

Development and function of gametophytes are crucial for plant reproduction. However, relatively little is known about the molecular basis of embryo sac development. We characterized a Ds insertion line (MEE 42) with defects in female transmission efficiency. The phenotype of MEE 42 was studied by DIC microscopy of whole-mount preparations of ovules. Mutant ovuleswere found to be affected during post-pollination processes. Embryo development was arrested at one-cell zygotic stage. Endosperm development was also arrested. Some ovules appearedunfertilized, suggesting that the mutation is also affecting pollen tube (PT) guidance or fertilization. To further study the nature of the fertilization failure, we analyzed PT growth patterns by anilineblue staining. Although pollen tubes were found at the micropyle of both WT and mutant ovules, some mutant ovules showed abnormal PT growth patterns. To characterize the identity of the synergide cells -responsible for PT attraction- we tested the expression of a synergide marker. Similar GUS staining patterns were observed in WT and MEE42 mutant embryo sacs. The flanking sequence of the Ds element was confirmed for the 5’ end of the DS element byusing Ds and specific primers to be in At3g63080, encoding a glutathione peroxidase.