The Arabidopsis LFR Gene Is Required for the Formation of Anther Cell Layers and Normal Expression of Key Regulatory Genes

Abstract

The anther is the male reproductive organ in flowering plants. Although some genes were reported to be involved in anther development, the molecular mechanisms underlying the transcriptional regulation of these genes is unclear. lfr-2 (leaf and flower related-2), the null allele of Arabidopsis thaliana LFR (LEAF AND FLOWER RELATED), was male-sterile. The anthers of lfr-2 plants were defective in sporogenous cell formation, tapetum development, and pollen development. In agreement with these phenotypes, expression studies showed that LFR was expressed in all cell layers of the anther, and that expression was particularly strong in the tapetal cells and pollen grains. Quantitative RT-PCR analysis revealed that LFR is required for the normal transcription of some anther development-related genes, such as AMS, CALS5, and DYT1, MS1 and MS2, and ROXY2. Genetic analysis showed that SPL was epistatic to LFR while LFR was epistatic to DYT1. We propose that LFR may be a crucial component in the regulation of a genetic network that modulates anther development.

Dynamic Changes in ANGUSTIFOLIA3 Complex Composition Reveal a Growth Regulatory Mechanism in the Maize Leaf

“…LFR is very broadly expressed in the different Arabidopsis organs but reaches its highest expression levels in young growing tissue. Mutation of LFR results in a delay in leaf appearance, narrow leaves, and even male sterility (Wang et al, 2009;Wang et al, 2012). LUH is a transcriptional corepressor belonging to the same class as LEUNIG (LUG) (Causier et al, 2012), which was also identified in all performed maize TAP experiments.…”

Scalable Phylogenetic Profiling using MinHash Uncovers Likely Eukaryotic Sexual Reproduction Genes

“…One particular family of interest which was returned in our search results is already characterized in angiosperms: LFR or leaf and flower related [40] . This protein family is required for the development of reproductive structures in flowers and serves as a master regulator of the expression of many reproduction related genes, but its role in lower eukaryotes remains undescribed despite its broad evolutionary conservation.…”

One novel cis-element is essential for correct DYSFUNCTIONAL TAPETUM 1 (DYT1) expression in Arabidopsis thaliana

“…Most of anther regulatory genes, including TDF1, AMS, AtMYB80 are found to be downstream of DYT1 (Sorensen et al 2003;Zhu et al 2008;Phan et al 2012), and very few seem to occupy the upstream position. As mentioned before, SPL/NZZ and LFR are upstream of DYT1 (Bencivenga et al 2012;Wang et al 2012); however, none of these genes is anther specific and cannot confer DYT1 0 s anther-specific expression. Thus, other unknown upstream gene(s) should collaborate with SPL/NZZ and LFR to confer the male organ-specific expression profile of DYT1.…”

“…In Arabidopsis thaliana SPL/NZZ, LFR, EMS1/EXS and TPD1, etc., have been found as DYT1-upstream genes (Yang et al 1999(Yang et al , 2003(Yang et al , 2005Canales et al 2002;Zhao et al 2002;Wijeratne et al 2007;Liu et al 2009;Wang et al 2012). Under the mutant backgrounds of these genes, DYT1 expression is largely down-regulated (Zhang et al 2006).…”

“…EMS1/EXS and TPD1 as a receptor-like kinase and a ligand genes respectively, much likely regulate DYT1 expression through a protein phosphorylation pathway (Canales et al 2002;Zhao et al 2002;Yang et al 2003). Both SPL/NZZ and LFR encode putative nuclear proteins involved in transcription regulation (Schiefthaler et al 1999;Yang et al 1999;Wang et al 2012). However, even if SPL/NZZ has been found to play a fundamental role in both male and female gametogenesis long before (Ye et al 2010;Bencivenga et al 2012), no recognition site, such as DNA-binding motif of SPL/NZZ, or LFR, has been reported.…”