Expression analysis of the Arabidopsis thaliana AtSpen2 gene, and its relationship with other plant genes encoding Spen proteins

Abstract

Proteins of the Split ends (Spen) family are characterized by an N-terminal domain, with one or more RNA recognition motifs and a SPOC domain. In Arabidopsis thaliana, the Spen protein FPA is involved in the control of flowering time as a component of an autonomous pathway independent of photoperiod. The A. thaliana genome encodes another gene for a putative Spen protein at the locus At4g12640, herein named AtSpen2. Bioinformatics analysis of the AtSPEN2 SPOC domain revealed low sequence similarity with the FPA SPOC domain, which was markedly lower than that found in other Spen proteins from unrelated plant species. To provide experimental information about the function of AtSpen2, A. thaliana plants were transformed with gene constructs of its promoter region with uidA::gfp reporter genes; the expression was observed in vascular tissues of leaves and roots, as well as in ovules and developing embryos. There was absence of a notable phenotype in knockout and overexpressing lines, suggesting that its function in plants might be specific to certain endogenous or environmental conditions. Our results suggest that the function of Atspen2 diverged from that of fpa due in part to their different transcription expression pattern and divergence of the regulatory SPOC domain.

SUPER STARCHY1/ONAC025 participates in rice grain filling

“…Hence, a direct correlation between expression and phenotype intensity amongst these lines cannot be determined. The phenotype of lesser effect on height in L_8 may be due to a positional effect of the gene (Matzke and Matzke, 1998; Solís‐Guzmán et al, 2017).…”

Histone 2B monoubiquitination complex integrates transcript elongation with RNA processing at circadian clock and flowering regulators

“…Some of the mammalian Spen proteins regulate gene expression via the control of splicing activity (26)(27)(28). In the Arabidopsis genome, only three Spen proteins were retrieved that combined SPOC with one or more RRM motifs: (i) the SPEN3 protein studied in this work with one RRM, (ii) the SPEN2 (AT4G12640) protein with two RRMs with an unknown function [because the knockout and overexpressing lines had no apparent phenotype (29)], and (iii) the flowering-time regulator FPA with three RRMs that controls alternative splicing and polyadenylation of antisense transcripts of the floral repressor FLC (30). The role in floweringtime regulation has also been suggested in rice (Oryza sativa) for the Spen protein encoded by the OsRRMh gene with two RRM motifs, as indicated by the flowering-time delay in the knockdown line (31).…”