IMPACT OF HEAVY METALS ON PHYSIOLOGICAL AND PROTEOMIC RESPONSES OF WILLOWS (SALIX SP.)

Poster (2012)

In 2010, around 3,800 sites in Wallonia (Belgium) were identified as potentially contaminated by heavy metals, a result of their past industrial and agricultural activities [1]. The technique of using ... [more ▼]

In 2010, around 3,800 sites in Wallonia (Belgium) were identified as potentially contaminated by heavy metals, a result of their past industrial and agricultural activities [1]. The technique of using plants to remediate contaminated sites (phytoremediation) has been studied for over twenty years. In particular, the use of trees (alder, willow, poplar) has been considered because of their large biomass production [2] [3] [4] [5]. The aim of this study was to identify the potential of local willow ecotypes to grow in the presence of heavy metals using lysimeters filled with dredging sludge. Several willow ecotypes were compared realizing morphological and physiological measurements (chlorophyll fluorescence, electrolyte leakage, carbohydrate content). The plant responses to metal stress were also investigated using a proteomic approach. Heavy metals contents in leaves and stems were analysed. With this study, the potential of these trees to valorise contaminated, abandoned sites in Belgium was evaluated. [1] Cellule Etat de l'environnement wallon (2010). Tableau de bord de l'environnement wallon. SPW-DGARNE-DEMNA-DEE. [2] Dickinson N. M. (2000). Strategies for sustainable woodland on contaminated soils. Chemosphere 41(1-2): 259-263. [3] Meers E., Lamsal S., Vervaeke P., Hopgood M., Lust N. and Tack F. M. G. (2005). Availability of heavy metals for uptake by Salix viminalis on a moderately contaminated dredged sediment disposal site. Environ Pollut 137(2): 354-364. [4] Meers E., Vandecasteele B., Ruttens A., Vangronsveld J. and Tack F. M. G. (2007). Potential of five willow species (Salix spp.) for phytoextraction of heavy metals. Environ Exp Bot 60(1): 57-68. [5] Rosselli W., Keller C. and Boschi K. (2003). Phytoextraction capacity of trees growing on a metal contaminated soil. Plant Soil 256(2): 265-272. [less ▲]

What we have learned about the physiology of in vitro adventitious rooting of woody plants and how it relates to improvements in the practice

in Niemi, Karoliina (Ed.) Adventitious root formation of forest trees and horticultural plants - from genes to applications (2009)

Natural auxins and synthetic analogs are the most powerful exogenous stimulators of adventitious rooting of ligneous as well as for herbaceous cuttings. For several years we have investigated the ... [more ▼]

Natural auxins and synthetic analogs are the most powerful exogenous stimulators of adventitious rooting of ligneous as well as for herbaceous cuttings. For several years we have investigated the physiology of rooting, including the metabolism of endogenous auxins and their molecular mechanisms of action. Our work has resulted in discoveries leading to practical strategies allowing faster and improved rooting of cuttings from shoots raised in vitro, and subsequently resulting in roots better adapted for acclimatization and to overcome so-called (apparent) recalcitrance-to-rooting of some species. In this chapter we describe: (i) how variation in auxin treatments during rooting can be used to regulate the endogenous levels of auxins; (ii) the importance of not maintaining auxin treatment throughout the whole rooting process, thereby the endogenous auxin level itself not always being high; (iii) the division of the organogenetic process into at least three main rooting interdependent phases, i.e. induction, initiation, and expression, with different durations depending on the species and with different requirements for each phase, and (iv) how polyamines, even if less effective from outside, and their metabolism are as important as auxins in the rooting process. We will also describe how cross-talk between hormones, manipulations with related genes and mutants, and some similarities between the induction of rooting and evocation of flowering, offer new tools for further progress in the field. [less ▲]

Quantitative changes in protein expression of cadmium-exposed poplar plants

in Proteomics (2008), 8

Two PR-1 loci detected in the native cultivated potato Solanum phureja appear differentially expressed upon challenge by late blight

in Physiological and Molecular Plant Pathology (2005), 67(3-5, SEP-OCT), 155-163

Plant pathogenesis-related proteins are toxic to invading pathogens. Among them, the Subfamily PR-1 represents low-molecular weight proteins of unknown biochemical function. Here, we describe the cloning ... [more ▼]

Plant pathogenesis-related proteins are toxic to invading pathogens. Among them, the Subfamily PR-1 represents low-molecular weight proteins of unknown biochemical function. Here, we describe the cloning and isolation of two PR-1 genes (PR-1b1 (GenBank accession no. SPH493450) and PR-1b2 (SPH493451)) that encode predicted basic proteins. We isolated them from Solanum phureja, a native Andean potato with horizontal resistance to late blight, caused by the oomycete Phytoplithora infestans. We demonstrate that the PR-1 genes belong to a small multigene family with an estimated copy number of 4-6 with one of them located oil chromosome IX as determined by genetic mapping. The expression of PR-1 genes was different in late blight resistant and Susceptible genotypes. Therefore, we propose that both PR-1 genes may play a role in horizontal late blight resistance of S. phureja. (c) 2006 Elsevier Ltd. All rights reserved. [less ▲]

Carbohydrates and resistance to Phytophthora infestans in potato plants

in Acta Physiologiae Plantarum (2003), 25(2), 171-178

Plants generally deal with biotic or abiotic stresses by altering components as for example cell wall constituents and metabolites. Infection by Phytophthora infestans, the causal agent of late blight ... [more ▼]

Plants generally deal with biotic or abiotic stresses by altering components as for example cell wall constituents and metabolites. Infection by Phytophthora infestans, the causal agent of late blight, constitutes a stress condition for the plants and they react to it with changes arising in their metabolism depending on the resistance level of the plants. The present work compares two potato hybrids differing in their level of horizontal resistance to late blight. Carbohydrate content in stems and leaves of infected and uninfected plants was determined by HPLC. Some carbohydrates accumulated in the stems of the resistant hybrid infected by P. infestans, whereas they remained unchanged in the susceptible hybrid. On the other hand, in the leaves, these carbohydrates accumulated only in the infected susceptible hybrid. [less ▲]

Auxins in the biology of roots

in Waisel, Yoav; Eshel, Amram; Kafkafi, Uzi (Eds.) Auxins in the biology of roots (2002)

Integrating phytohormone metabolism and action with primary biochemical pathways. I. Interrelationships between auxins, cytokinins, ethylene and polyamines in growth and development processes

in Greppin, Hubert; Penel, Claude; Broughton, Walter (Eds.) et al Integrated Plant Systems (2000)

The paper begins with a review of the phytohormone (plant hormone) concept vs the sense of the mammalian hormones. The term "plant growth regulators" including new naturally occurring substances is ... [more ▼]

The paper begins with a review of the phytohormone (plant hormone) concept vs the sense of the mammalian hormones. The term "plant growth regulators" including new naturally occurring substances is discussed in regard to their effects on both growth and development processes, and possible different mechanisms of action in two different physiological directions. Mutual interactions between auxins, cytokinins, ethylene and polyamines are examined in several growth and development processes, showing the complexity of approach of the hormonal actions in plants . The indissociability of some hormonal relationships, and their obligatory integration with primary biochemical pathways is finally shown. [less ▲]

Changes in the Concentrations of Auxins and Polyamines During Rooting of in-Vitro-Propagated Walnut Shoots

in Tree Physiology (1996), 16(5), 515-9

Rooting was induced in in-vitro-propagated walnut (Juglans regia L.) shoots by subculturing the shoots on rooting medium containing agar and 3 mg l(-1) indole-3-butyric acid (IBA) for 7 days in darkness ... [more ▼]

Rooting was induced in in-vitro-propagated walnut (Juglans regia L.) shoots by subculturing the shoots on rooting medium containing agar and 3 mg l(-1) indole-3-butyric acid (IBA) for 7 days in darkness. Changes in the concentrations of endogenous free indole-3-acetic acid (IAA), indole-3-acetylaspartic acid (IAAsp) and free polyamines were determined during culture on root-inducing medium. In extracts of whole shoots, the concentration of free IAA showed a transient peak at 60 h (around 48 h in extracts from basal shoot portions) and then remained at a relatively low concentration for the remainder of the 7-day culture period. The concentration of IAAsp in extracts of whole shoots peaked at about the same time as the concentration of free IAA, whereas the IAAsp concentration in extracts from basal shoot portions peaked earlier, at around 12 h. The concentrations of free polyamines in extracts of whole shoots increased soon after the shoots were transferred to root-inducing medium. The concentrations of IAA and IAAsp remained stable when the rooted shoots were transferred to a vermiculite/gelrite mixture (without auxin) and grown in light. [less ▲]