Exploring Redox Modulation of Plant UDP-Glucose Pyrophosphorylase.

UDP-glucose (UDPG) pyrophosphorylase (UGPase) catalyzes a reversible reaction, producing UDPG, which serves as an essential precursor for hundreds of glycosyltransferases in all organisms. In this study, activities of purified UGPases from sugarcane and barley were found to be reversibly redox modulated in vitro through oxidation by hydrogen peroxide or oxidized glutathione (GSSG) and through reduction by dithiothreitol or glutathione. Generally, while oxidative treatment decreased UGPase activity, a subsequent reduction restored the activity.

A MITE insertion abolishes the AP3-3 self-maintenance regulatory loop in apetalous flowers of Nigella damascena.

MADS-box transcription factors are important regulators of floral organ identity through their binding to specific motifs, termed CArG, in the promoter of their target genes. Petal initiation and development depend on class A and B genes, but MADS-box genes of the APETALA3 (AP3) clade are key regulators of this process. In the early diverging eudicot Nigella damascena, an apetalous [T] morph is characterized by the lack of expression of the NdAP3-3 gene, with its expression being petal-specific in the wild-type [P] morph.

AGO104 is a RdDM effector of paramutation at the maize b1 locus.

Although paramutation has been well-studied at a few hallmark loci involved in anthocyanin biosynthesis in maize, the cellular and molecular mechanisms underlying the phenomenon remain largely unknown. Previously described actors of paramutation encode components of the RNA-directed DNA-methylation (RdDM) pathway that participate in the biogenesis of 24-nucleotide small interfering RNAs (24-nt siRNAs) and long non-coding RNAs. In this study, we uncover an ARGONAUTE (AGO) protein as an effector of the RdDM pathway that is in charge of guiding 24-nt siRNAs to their DNA target to create de novo DNA methylation.