Publications by authors named "Melissa S Hillwig"

Comparison of Arabidopsis thaliana (Arabidopsis) gene expression induced by Myzus persicae (green peach aphid) feeding, aphid saliva infiltration and abscisic acid (ABA) treatment showed a significant positive correlation. In particular, ABA-regulated genes are over-represented among genes that are induced by M. persicae saliva infiltration into Arabidopsis leaves.

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RNase T2 enzymes are conserved in most eukaryotic genomes, and expression patterns and phylogenetic analyses suggest that they may carry out an important housekeeping role. However, the nature of this role has been elusive. Here we show that RNS2, an intracellular RNase T2 from Arabidopsis thaliana, is essential for normal ribosomal RNA recycling.

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T2-family acidic endoribonucleases are represented in all genomes. A physiological role for RNase T2 has yet to be defined for metazoa. RNASET2 mutation in humans is linked with a leukoencephalopathy that arises in infancy characterized by cortical cysts and multifocal white matter lesions.

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Article Synopsis
  • Previous SDS PAGE gel analysis showed distinct protein patterns in floral nectars from petunia and tobacco, with petunia nectar containing significant RNase activities.
  • To identify the active proteins, RNase bands were excised, digested with trypsin, and analyzed through LC-MS/MS, revealing S-RNases and other proteins like peroxidases and fructokinases.
  • RT-PCR assays confirmed the expression of these proteins in petunia floral nectary, highlighting their potential role in antimicrobial activity within nectar.
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Article Synopsis
  • Plants often create nectar to attract insect pollinators, which can lead to microbial growth, so they develop mechanisms to prevent this.
  • In Nicotiana species, hydrogen peroxide provides anti-microbial action, while Petunia hybrida shows antibacterial properties through different means, despite lower hydrogen peroxide levels.
  • Research revealed unique RNase proteins in petunia nectar, suggesting evolutionary links between these enzymes and defense mechanisms in flowers, marking the first discovery of RNase activities in nectar.
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The plant RNase T2 family is divided into two different subfamilies. S-RNases are involved in rejection of self-pollen during the establishment of self-incompatibility in three plant families. S-like RNases, on the other hand, are not involved in self-incompatibility, and although gene expression studies point to a role in plant defense and phosphate recycling, their biological roles are less well understood.

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Background: Members of the Ribonuclease (RNase) T2 family are common models for enzymological studies, and their evolution has been well characterized in plants. This family of acidic RNases is widespread, with members in almost all organisms including plants, animals, fungi, bacteria and even some viruses. While several biological functions have been proposed for these enzymes in plants, their role in animals is unknown.

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Injured plants induce a wide range of genes whose products are thought to help to repair the plant or to defend against opportunistic pathogens that might infect the wounded plant. In Arabidopsis thaliana L., oligogalacturonides (OGAs) and jasmonic acid (JA) are the main regulators of the signaling pathways that control the local and systemic wound response, respectively.

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