Identification and characterization of a female gametophyte defect in sdk1-7 +/- abi3-6 +/- heterozygotes of Arabidopsis thaliana

Abstract

Successful reproduction in angiosperms is dependent on the highly synchronous development of their male and female gametophytes and the ensuing fusion of the gametes from these reproductive tissue types. When crossing a T-DNA insertion line sdk1-7-/-(Salk_024564), one of the S-domain receptor kinases involved in ABA responses with a fast neutron deletion line abi3-6-/-, the F1 heterozygotes (sdk1-7+/-abi3-6 +/-) displayed 50% ovule abortion suggesting a likely gametophytic defects. We identified and characterized an early stage female gametophyte developmental defect in the heterozygous mutant ovules. Recombination frequency analysis of the F2 progenies from selfed heterozygotes revealed a possible pseudo-linkage of sdk1-7 and abi3-6 suggesting a reciprocal translocation event in the heterozygote. Our study emphasizes the importance of robust analysis to distinguish gametophytic defect phenotypes caused by genetic interactions and that resulting from possible chromosomal translocation events.

Hormonal Regulation of Ovule Initiation in Arabidopsis

“…Regarding JA, it has been shown that JA regulates stamen development in Arabidopsis but also late ovule development and fertility in tomato through the function of MYC2/JAI1 (Schubert et al 2019;Huang et al 2023). In the case of ABA, it was reported a high ovule abortion in F1 plants from the cross of sdk1-7, one of the S-domain receptor kinases involved in ABA responses, with a null abi3-6 (Sankaranarayanan et al 2020). A more detailed analysis is the specific role of these hormones, and other plant growth regulators in ovule development would be crucial to better understand the complex hormonal network governing ovule primordia emergence.…”