Functional Analysis of Sporophytic Transcripts Repressed by the Female Gametophyte in the Ovule of Arabidopsis thaliana

Abstract

To investigate the genetic and molecular regulation that the female gametophyte could exert over neighboring sporophytic regions of the ovule, we performed a quantitative comparison of global expression in wild-type and nozzle/sporocyteless (spl) ovules of Arabidopsis thaliana (Arabidopsis), using Massively Parallel Signature Sequencing (MPSS). This comparison resulted in 1517 genes showing at least 3-fold increased expression in ovules lacking a female gametophyte, including those encoding 89 transcription factors, 50 kinases, 25 proteins containing a RNA-recognition motif (RRM), and 20 WD40 repeat proteins. We confirmed that eleven of these genes are either preferentially expressed or exclusive of spl ovules lacking a female gametophyte as compared to wild-type, and showed that six are also upregulated in determinant infertile1 (dif1), a meiotic mutant affected in a REC8-like cohesin that is also devoided of female gametophytes. The sporophytic misexpression of IOREMPTE, a WD40/transducin repeat gene that is preferentially expressed in the L1 layer of spl ovules, caused the arrest of female gametogenesis after differentiation of a functional megaspore. Our results show that in Arabidopsis, the sporophytic-gametophytic cross talk includes a negative regulation of the female gametophyte over specific genes that are detrimental for its growth and development, demonstrating its potential to exert a repressive control over neighboring regions in the ovule.

Identification of lncRNAs involved in rice ovule development and female gametophyte abortion by genome-wide screening and functional analysis

“…In recent years, researchers have identified crosstalk between the ovule sporophytic tissue and female gametophyte [15]. Changes in gene expression in the ovule sporophytic tissue will affect the normal growth and development of the female gametophyte, and gene expression in the female gametophyte will also affect ovule sporophytic tissue [16–19].…”

The meiotic transcriptome architecture of plants

“…In contrast to the relatively well-studied male meiotic transcriptome, female meiosis was less examined so far, probably due to the difficulties to obtain the corresponding material of whole early pistils or even isolated megaspore mother cells. One study examined the stigma transcriptome (Li et al, 2007 ), and genetic ablation was used to study genes preferentially expressed in the mature ovule (Sanchez-Leon et al, 2012 ; Armenta-Medina et al, 2013 ) and in the mature embryo sac (Johnston et al, 2007 ; Jones-Rhoades et al, 2007 ; Steffen et al, 2007 ). Furthermore, individual cell types in the mature embryo sac were examined (Wuest et al, 2010 ; Ohnishi et al, 2011 ), but all these studies looked at post-meiotic transcriptomes.…”

Genome-wide transcriptome analysis of female-sterile rice ovule shed light on its abortive mechanism

“…Early investigations have proved that crosstalk exists between the female gametophyte and sporophytic ovule tissues (Bencivenga et al 2011). The genes expressed in the sporophytic ovule tissues can affect the female gametophyte development, and the female gametophyte can also affect the sporophyte ovule tissues (Johnston et al 2007;Armenta-Medina et al 2013).…”