Background SFARs (seed fatty acid reducers) belonging to the GDSL lipases/esterases family have been reported to reduce fatty acid storage and composition in mature Arabidopsis seeds. GDSL lipases/esterases are hydrolytic enzymes that possess multifunctional properties, such as broad substrate specificity, regiospecificity, and stereoselectivity. Studies on the physiological functions and biochemical characteristics of GDSL lipases/esterases in plants are limited, so it is important to elucidate the molecular functions of GDSL-type genes.ResultsWe found that SFAR4 (At3g48460), a fatty acid reducer belonging to the Arabidopsis GDSL lipases/esterases family, was intensely expressed in embryo protrusion, early seedlings, and pollen. The characterization of recombinant SFAR4 protein indicated that it has short-length p-nitrophenyl esterase activity. In addition, SFAR4 enhanced the expression of genes involved in fatty acid metabolism during seed germination and seedling development. SFAR4 elevated the expression of COMATOSE, which transports fatty acids into peroxisomes, and of LACS6 and LACS7, which deliver long-chain acetyl-CoA for β-oxidation. Furthermore, SFAR4 increased the transcription of PED1 and PNC1, which function in importing peroxisomal ATP required for fatty acid degradation. SFAR4 has another function on tolerance to high glucose concentrations but had no significant effects on the expression of the glucose sensor HXK1.ConclusionsThe results demonstrated that SFAR4 is a GDSL-type esterase involved in fatty acid metabolism during post-germination and seedling development in Arabidopsis. We suggested that SFAR4 plays an important role in fatty acid degradation, thus reducing the fatty acid content.Electronic supplementary materialThe online version of this article (doi:10.1186/s40529-015-0114-6) contains supplementary material, which is available to authorized users.

Epigenetic regulation of gene expression is of fundamental importance for eukaryotic development. EMBRYONIC FLOWER1 (EMF1) is a plant-specific gene that participates in Polycomb group-mediated transcriptional repression of target genes such as the flower MADS box genes AGAMOUS, APETALA3, and PISTILLATA. Here, we investigated the molecular mechanism underlying the curly leaf and early flowering phenotypes caused by reducing EMF1 activity in the leaf primordia of LFYasEMF1 transgenic plants and propose a combined effect of multiple flower MADS box gene activities on these phenotypes. ULTRAPETALA1 (ULT1) functions as a trithorax group factor that counteracts Polycomb group action in Arabidopsis (Arabidopsis thaliana). Removing ULT1 activity rescues both the abnormal developmental phenotypes and most of the misregulated gene expression of LFYasEMF1 plants. Reducing EMF1 activity increases salt tolerance, an effect that is diminished by introducing the ult1-3 mutation into the LFYasEMF1 background. EMF1 is required for trimethylating lysine-27 on histone 3 (H3K27me3), and ULT1 associates with ARABIDOPSIS TRITHORAX1 (ATX1) for trimethylating lysine-3 on histone 4 (H3K4me3) at flower MADS box gene loci. Reducing EMF1 activity decreases H3K27me3 marks and increases H3K4me3 marks on target gene loci. Removing ULT1 activity has the opposite effect on the two histone marks. Removing both gene activities restores the active and repressive marks to near wild-type levels. Thus, ULT1 acts as an antirepressor that counteracts EMF1 action through modulation of histone marks on target genes. Our analysis indicates that, instead of acting as off and on switches, EMF1 and ULT1 mediate histone mark deposition and modulate transcriptional activities of the target genes.

BackgroundBruchid beetles are an important storage pest of grain legumes. Callosobruchus sp. infect mungbean (Vigna radiata) at low levels in the field, multiply during grain storage and can destroy seed stocks in a few months. Resistance against bruchid beetles has been found in wild mungbean V. radiata var. sublobata TC1966 and in cultivated mungbean line V2802.ResultsBruchid resistance data were obtained from recombinant inbred line populations TC1966 (V. radiata var. sublobata) × NM92 (F12) and V2802 (V. radiata) × NM94 (F7). More than 6,000 single nucleotide polymorphic markers were generated through genotyping by sequencing (GBS) for each of these populations and were used to map bruchid resistance genes. One highly significant quantitative trait locus (QTL) associated with bruchid resistance was mapped to chromosome 5 on genetic maps of both populations, suggesting that TC1966 and V2802 contain the same resistance locus. Co-segregation of all markers associated with resistance indicated the presence of only one major resistance QTL on chromosome 5, while QTL analysis based on physical map positions of the markers suggested the presence of multiple QTLs on different chromosomes. The diagnostic capacity of the identified molecular markers located in the QTL to correctly predict resistance was up to 100 %.ConclusionsMolecular markers tightly linked to bruchid resistance loci of two different mungbean resistance sources were developed and validated. These markers are highly useful for developing resistant lines.Electronic supplementary materialThe online version of this article (doi:10.1186/s12870-016-0847-8) contains supplementary material, which is available to authorized users.

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