Molecular dynamics in germinating, endophyte-colonized quinoa seeds

Aims: The pseudo-cereal quinoa has an outstanding nutritional value. Seed germination is unusually fast, and plant tolerance to salt stress exceptionally high. Seemingly all seeds harbor bacterial endophytes. This work examines mitogen-activated protein kinase (MAPK) activities during early development. It evaluates possible contribution of endophytes to rapid germination and plant robustness. Methods: MAPK activities were monitored in water- and NaCl-imbibed seeds over a 4-h-period using an immunoblot-based approach. Cellulolytic and pectinolytic abilities of bacteria were assessed biochemically, and cellular movement, biofilm, elicitor and antimicrobial compound synthesis genes sequenced. GyrA-based, cultivation-independent studies provided first insight into endophyte diversity. Results: Quinoa seeds and seedlings exhibit remarkably complex and dynamic MAPK activity profiles. Depending on seed origin, variances exist in MAPK patterns and probably also in endophyte assemblages. Mucilage-degrading activities enable endophytes to colonize seed surfaces of a non-host species, chia, without apparent adverse effects. Conclusions: Owing to their motility, cell wall-loosening and elicitor-generating abilities, quinoa endophytes have the potential to drive cell expansion, move across cell walls, generate damage-associated molecular patterns and activate MAPKs in their host. Bacteria may thus facilitate rapid germination and confer a primed state directly upon seed rehydration. Transfer into non-native crops appears both desirable and feasible.V167-B09(VLID)190449

Symbiosis-regulated genes in Lotus japonicus

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Post-Translational Modification and Secretion of Azelaic Acid Induced 1 (AZI1), a Hybrid Proline-Rich Protein from Arabidopsis

Arabidopsis EARLI-type hybrid proline-rich proteins (HyPRPs) consist of a putative N-terminal secretion signal, a proline-rich domain (PRD), and a characteristic eight-cysteine-motif (8-CM). They have been implicated in biotic and abiotic stress responses. AZI1 is required for systemic acquired resistance and it has recently been identified as a target of the stress-induced mitogen-activated protein kinase MPK3. AZI1 gel migration properties strongly indicate AZI1 to undergo major post-translational modifications. These occur in a stress-independent manner and are unrelated to phosphorylation by MAPKs. As revealed by transient expression of AZI1 in Nicotiana benthamiana and Tropaeolum majus, the Arabidopsis protein is similarly modified in heterologous plant species. Proline-rich regions, resembling arabinogalactan proteins point to a possible proline hydroxylation and subsequent O-glycosylation of AZI1. Consistently, inhibition of prolyl hydroxylase reduces its apparent protein size. AZI1 secretion was examined using Arabidopsis protoplasts and seedling exudates. Employing Agrobacterium-mediated leaf infiltration of N. benthamiana, we attempted to assess long-distance movement of AZI1. In summary, the data point to AZI1 being a partially secreted protein and a likely new member of the group of hydroxyproline-rich glycoproteins. Its dual location suggests AZI1 to exert both intra- and extracellular functions

<i>Tropaeolum</i> Tops Tobacco – Simple and Efficient Transgene Expression in the Order Brassicales

<div><p>Transient expression systems are valuable tools in molecular biology. Agrobacterial infiltration of leaves is well-established in tobacco, but has led to limited success in the model plant <i>Arabidopsis thaliana</i>. An efficient expression system combining the advantages of <i>Arabidopsis</i> (well-characterised) and the simplicity of leaf infiltration is desirable. Here, I describe <i>Agrobacterium tumefaciens</i>-mediated transformation of <i>Tropaeolum</i><i>majus</i> (nasturtium, order Brassicales) as a remarkably simple, cheap and highly efficient transient expression system. It provides the <i>Arabidopsis</i> community with a tool to study subcellular localisation, protein–protein interactions and reporter gene activities (e.g. luciferase, β-glucuronidase) in a genetic background that is closely related to their primary model organism. Unlike <i>Arabidopsis</i><i>, </i><i>Tropaeolum</i> is capable of engaging in endomycorrhizal associations and is therefore relevant also to symbiosis research. RNAi-based approaches are more likely to succeed than in the distantly-related <i>Nicotiana</i> transformation system. <i>Tropaeolum</i><i>majus</i> was voted the “medicinal plant of the year 2013”. Conquering this plant for genetic manipulations harbours potential for biotechnological and pharmacological applications.</p> </div

Comparison of protein profiles in <i>Arabidopsis</i><i>, </i><i>N</i><i>. benthamiana</i> and <i>Tropaeolum</i><i>majus</i>.

<p>20 µg protein extracted from <i>Arabidopsis</i> rosette leaves, <i>Nicotiana</i><i>benthamiana</i> or <i>Tropaeolum</i><i>majus</i> leaves were separated by SDS-PAGE (12%) and visualised by Coomassie Blue staining.</p

Poinsettia protoplasts - a simple, robust and efficient system for transient gene expression studies

Abstract Background Transient gene expression systems are indispensable tools in molecular biology. Yet, their routine application is limited to few plant species often requiring substantial equipment and facilities. High chloroplast and chlorophyll content may further impede downstream applications of transformed cells from green plant tissue. Results Here, we describe a fast and simple technique for the high-yield isolation and efficient transformation (>70%) of mesophyll-derived protoplasts from red leaves of the perennial plant Poinsettia (Euphorbia pulccherrima). In this method no particular growth facilities or expensive equipments are needed. Poinsettia protoplasts display an astonishing robustness and can be employed in a variety of commonly-used downstream applications, such as subcellular localisation (multi-colour fluorescence) or promoter activity studies. Due to low abundance of chloroplasts or chromoplasts, problems encountered in other mesophyll-derived protoplast systems (particularly autofluorescence) are alleviated. Furthermore, the transgene expression is detectable within 90 minutes of transformation and lasts for several days. Conclusions The simplicity of the isolation and transformation procedure renders Poinsettia protoplasts an attractive system for transient gene expression experiments, including multi-colour fluorescence, subcellular localisation and promoter activity studies. In addition, they offer hitherto unknown possibilities for anthocyan research and industrial applications.</p

Angiosperm phylogeny and phylogenetic relation within the order Brassicacales.

<p>Positions of plant species mentioned in the manuscript are indicated. The image was modified from the „Angiosperm Phylogeny Website – Missouri Botanical Garden“. Reprinted from http://www.mobot.org/MOBOT/research/APweb/ under a CC BY license, with permission from Peter F. Stevens, original copyright 2013. (<a href="http://www.mobot.org/mobot/research/apweb/" target="_blank"><u>http://www.mobot.org/MOBOT/research/APweb/</u></a>).</p

Leaf appearance after infiltration.

<p><b>A</b>) symptom-free leaf at 7 days post-infiltration. <b>B</b>) necrosis in leaves 21 days post-infiltration. Note that symptoms occur only around the infiltration site (syringe release) but not in the remaining infiltrated area.</p