1,312 research outputs found
Discovering the role of mitochondria in the iron deficiency-induced metabolic responses of plants
No full textIn plants, iron (Fe) deficiency-induced chlorosis is a major problem, affecting both yield and quality of crops. Plants have evolved multifaceted strategies, such as reductase activity, proton extrusion, and specialised storage proteins, to mobilise Fe from the environment and distribute it within the plant. Because of its fundamental role in plant productivity, several issues concerning Fe homeostasis in plants are currently intensively studied. The activation of Fe uptake reactions requires an overall adaptation of the primary metabolism because these activities need the constant supply of energetic substrates (i.e., NADPH and ATP). Several studies concerning the metabolism of Fe-deficient plants have been conducted, but research focused on mitochondrial implications in adaptive responses to nutritional stress has only begun in recent years. Mitochondria are the energetic centre of the root cell, and they are strongly affected by Fe deficiency. Nevertheless, they display a high level of functional flexibility, which allows them to maintain the viability of the cell. Mitochondria represent a crucial target of studies on plant homeostasis, and it might be of interest to concentrate future research on understanding how mitochondria orchestrate the reprogramming of root cell metabolism under Fe deficiency. In this review, I summarise what it is known about the effect of Fe deficiency on mitochondrial metabolism and morphology. Moreover, I present a detailed view of the possible roles of mitochondria in the development of plant responses to Fe deficiency, integrating old findings with new and discussing new hypotheses for future investigations
Understanding plant nutrition for a sustainable agriculture
No full textNowadays a worrying requirement of food haunts the scientific community: crop production must double to keep pace with growth in the global population, which will reach 9 billion people by the year 2050. Additionally, a decrease in available arable land has been estimated, therefore the plant science community should provide solutions to maintain and increase food production. Plants represent an important food source for both humans and animals. Plant production strongly depends on the availability of mineral nutrients. Macronutrients (i.e. nitrogen, phosphate, potassium, sulphate) and micronutrients (i.e. iron, copper, zinc) are essential for various aspects of plant growth and development.
To cope with nutrient limitations, plants have developed a set of physiological and morphological responses to match resource availability with growth requirements. Such responses are regulated by a complex sensing and signaling mechanism that allows plants to monitor the external and internal concentration of mineral nutrients. Understanding such mechanisms represent a major issue in plant physiology and crop production, with potential impact on the design of new biofortification strategies for improving yields as well as the nutritional value of crops.
Nutrient sensing and signalling in plants involves both local and systemic pathways. When a variation in the nutrient availability is perceived by the cell, specific signal molecules induce a transcriptional reprogramming mechanism at the nucleus level. At the tissue level, roots are expected to play the initial role in sensing the local mineral nutrient status of the soil. Through a long-distance signalling pathway, nutrient stress signals reach all plant organs, inducing the plant adaptation mechanisms.
Here, the current knowledge about the nutrient sensing and signalling mechanisms related to some elements will be presented
Does a similar metabolic reprogramming occur in Fe-deficient plant cells and animal tumour cells?
No full textEffect of Fe deficiency on mitochondrial alternative NAD(P)H dehydrogenases in cucumber roots
No full textIron deficiency affects the function of respiratory chain, mainly at the complex I and complex II levels. Since plant mitochondria posses alternative NAD(P)H dehydrogenases located in the inner-membrane, oxidising NAD(P)H from both cytosol and matrix, we investigated these activities in mitochondria of Fe-deficient roots. External and internal NAD(P)H dehydrogenase activities increased in Fe-deficient mitochondria. Accordingly, NDB1 protein strongly accumulates while NDA1 does not show relevant differences in Fe-deficient roots. The data presented support, for the first time, the hypothesis that Fe deficiency induces the alternative NAD(P)H dehydrogenases bypassing the impaired complex I
The fate and the role of mitochondria in Fe-deficient root of strategy I plants
No full textSilicon is the second most abundant mineral element in soil, it has important role in alleviating various environmental stresses and enhancing plant resistance against pathogen, but the exact mechanism by which Si mediates pathogen resistance remains unclear. One of the resistance mechanisms is related to silicon deposition in leaf that acts as a physical barrier to hinder pathogen penetration. But more evidence show that silicon can induce defense responses that are functionally similar to systemic acquired resistance, Si-treated plants can significantly increase antioxidant enzyme activities and the production of antifungal compounds such as phenolic metabolism product, phytoalexins and pathogenesis-related proteins etc. Molecular and biochemical detections show that Si can activate the expression of defense-related genes and may play important role in the transduction of plant stress signal such as salicylic acid, jasmonic acid and ethylene
Iron-Requiring Enzymes in the Spotlight of Oxygen
No full textIron (Fe) is a cofactor required for a variety of essential redox reactions in plant metabolism. Thus, plants have developed a complex network of interacting pathways to withstand Fe deficiency, including metabolic reprogramming. This opinion aims at revisiting such reprogramming by focusing on: (i) the functional relationships of Fe-requiring enzymes (FeREs) with respect to oxygen; and (ii) the progression of FeREs engagement, occurring under Fe deficiency stress. In particular, we considered such progression of FeREs engagement as strain responses of increasing severity during the stress phases of alarm, resistance, and exhaustion. This approach can contribute to reconcile the variety of experimental results obtained so far from different plant species and/or different Fe supplies
PARAMETRI FISIOLOGICI E BIOCHIMICI ATTI AD EVIDENZIARE DIFFERENZE ADATTATIVE IN PORTAINNESTI DI VITE A DIVERSA SUSCETTIBILITA’ ALLO STRESS IDRICO
No full textLa maggior parte dei vigneti è collocata in zone semiaride che, date le caratteristiche lussureggianti delle piante, determinano una migliore qualità dei frutti. La scarsa, ma regolata irrigazione viene infatti adottata con lo scopo di inibire la crescita vegetativa della vite, migliorando al tempo stesso resa e qualità produttiva. Nonostante piante di Vitis siano in grado di sopravvivere anche a condizioni di siccità estreme, lo stess idrico è tuttavia responsabile di circa il 41% delle perdite di produzioni degli Stati Uniti. I genotipi oggetto del presente studio (Barbera franco di piede, portainnesti 161.49, SO4, 420 A,) sono stati scelti in funzione della loro importanza agronomica-produttiva e del grado di suscettibilità allo stress idrico imposto. Le prove sono state condotte in coltura idroponica allevando il materiale vegetale in una condizione di controllo e una, atta a simulare la condizione di stress idrico, mediante l’aggiunta di 100 g/L di polietilenglicole, una sostanza osmoticamente attiva. Dopo aver valutato il contenuto relativo di acqua fogliare (RWC), sono stati analizzati alcuni parametri direttamente correlabili alla chiusura stomatica (evapotraspirazione, conduttanza stomatica, CO2 interna), prima risposta allo stress idrico volta a ridurre la perdita di acqua attraverso la traspirazione. Poiché la chiusura degli stomi ABA- e Ca2+-dipendente causa una diminuzione della fotosintesi, dalle foglie dei genotipi oggetto di studio sono state estratte le membrane tilacoidali, su cui sono state eseguite misure di trasporto elettronico fotosintetico. Sempre a livello fogliare è stata inoltre valutata l’attività della RuBisCo, con lo scopo di correlare diversi livelli di fissazione della CO2, con un diverso grado di tolleranza allo stress. L’identificazione e la valutazione dei parametri che determinano una diversa tolleranza tra genotipi forniranno strumenti utili per a) lo screening di portainnesti a diversa suscettibilità b) la creazione di nuovi portainnesti dotati di maggiore efficienza nell’utilizzo di acqua
Regolazione dei meccanismi di acquisizione e di omeostasi del ferro in piante a strategia I : analisi biochimica e molecolare degli aspetti metabolici implicati
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