scholarly journals Transcriptional insights into sugarcane aquaporin genes under water deficit conditions

2021 ◽  
Author(s):  
DEVENDRA KUMAR
Keyword(s):  
Water Deficit ◽  
Water Status ◽  
Crop Productivity ◽  
Transcript Analysis ◽  
Efficient Utilization ◽  
Sod Activity ◽  
Antioxidant Responses ◽  
New Germplasm

Abstract Water deficit in soil during formative growth stage adversely hinders the crop productivity. Plant develop a key chain of mechanisms to cope these strains. Characterization of genotypes under water deficit will provide the basis for breeding new germplasm for efficient utilization of water and nutrients and adaptation to water stress. To achieve this, two tolerant (Co 98014 and Co 0118) and two sensitive (CoJ 85 and Co 89003) sugarcane genotypes were assessed for antioxidant responses followed by differential expression of three aquaporin genes (ShPIP2-1, ShPIP-5 and ShPIP2-6) under two water deficit conditions. The MDA and H2O2 contents were significantly higher (p<0.05) in sensitive genotypes as compared to tolerant ones, whereas SOD activity was higher (p<0.05) in tolerant than sensitive genotypes. The transcript analysis of AQPs reveals upregulation of ShPIP2;5, whereas down-regulation of ShPIP2;1 and ShPIP2;6 when plants were imposed to water deficit conditions. The findings under study suggested the role of PIP2 AQPs in regulation of plant water status under water deficit conditions.

scholarly journals Transcriptional insights into sugarcane aquaporin genes under water deficit conditions

2021 ◽  
Author(s):  
DEVENDRA KUMAR
Keyword(s):  
Water Deficit ◽  
Water Status ◽  
Antioxidant Response ◽  
Crop Productivity ◽  
Transcript Analysis ◽  
Efficient Utilization ◽  
Sod Activity ◽  
New Germplasm

Abstract Water deficit in soil during formative growth stage adversely hinders the crop productivity. Plant develop a key chain of mechanisms to cope these strains. Characterization of genotypes under water deficit will provide the basis for breeding new germplasm for efficient utilization of water and nutrients and adaptation to water stress. To achieve this, two tolerant (Co 98014 and Co 0118) and two sensitive (CoJ 85 and Co 89003) sugarcane genotypes were assessed for antioxidant response followed by differential expression of three aquaporin genes (ShPIP2-1, ShPIP-5 and ShPIP2-6) under two water deficit conditions. The MDA and H2O2 contents were significantly higher (p < 0.05) in sensitive genotypes as compared to tolerant ones, whereas SOD activity was higher (p < 0.05) in tolerant than sensitive genotypes. The transcript analysis of AQPs reveals upregulation of ShPIP2;5, whereas down-regulation of ShPIP2;1 and ShPIP2;6 when plants were imposed to water deficit conditions. The findings under study suggested the role of PIP2 AQPs in regulation of plant water status under water deficit conditions.

scholarly journals Identification of an isoflavonoid transporter required for the nodule establishment of the Rhizobium-Fabaceae symbiotic interaction

2021 ◽  
Author(s):  
Wanda Biala-Leonhard ◽  
Laura Zanin ◽  
Stefano Gottardi ◽  
Rita de Brito Francisco ◽  
Silvia Venuti ◽  
...  
Keyword(s):  
Functional Characterization ◽  
Crop Productivity ◽  
Signaling Cascades ◽  
Nutritional Deficiencies ◽  
White Lupin ◽  
Symbiotic Interaction ◽  
Phosphate Availability ◽  
Rhizobial Symbiosis

Nitrogen (N) as well as Phosphorus (P) are key nutrients determining crop productivity. Legumes have developed strategies to overcome nutrient limitation by e.g., forming a symbiotic relationship with N-fixing rhizobia and the release of P-mobilizing exudates and are thus able to grow without supply of N or P fertilizers. The legume-rhizobial symbiosis starts with root release of isoflavonoids, that act as signaling molecules perceived by compatible bacteria. Subsequently, bacteria release nod factors, which induce signaling cascades allowing the formation of functional N-fixing nodules. We report here the identification and functional characterization of a plasma membrane-localized MATE-type transporter (LaMATE2) involved in the release of genistein from white lupin roots. The LaMATE2 expression in the root is upregulated under N deficiency as well as low phosphate availability, two nutritional deficiencies that induce the release of this isoflavonoid. LaMATE2 silencing reduced genistein efflux and even more the formation of symbiotic nodules, supporting the crucial role of LaMATE2 in isoflavonoid release and nodulation. Furthermore, silencing of LaMATE2 limited the P-solubilization activity of lupin root exudates. Transport assays in yeast vesicles demonstrated that LaMATE2 acts as a proton-driven isoflavonoid transporter.

Diurnal changes in leaflet gas exchange, water status and antioxidant responses in Carapa guianensis plants under water-deficit conditions

2012 ◽  
Vol 35 (1) ◽  
pp. 13-21 ◽  
Author(s):  
Kaliene da Silva Carvalho ◽  
Hugo Alves Pinheiro ◽  
Reginaldo Alves Festucci-Buselli ◽  
Dalton Dias da Silva Júnior ◽  
Gledson Luiz Salgado de Castro ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Water Deficit ◽  
Water Status ◽  
Diurnal Changes ◽  
Antioxidant Responses ◽  
Carapa Guianensis

scholarly journals   Antioxidative mechanisms on selenium accumulation in Pteris vittata L., a potential selenium phytoremediation plant

2012 ◽  
Vol 58 (No. 3) ◽  
pp. 105-110 ◽  
Author(s):  
R.W. Feng ◽  
C.Y. Wei
Keyword(s):  
Superoxide Dismutase ◽  
Enzyme Activity ◽  
Pteris Vittata ◽  
Sod Activity ◽  
Antioxidant Responses ◽  
Industrial Activities ◽  
Chinese Brake Fern ◽  
Selenium Accumulation ◽  
Pteris Vittata L

Selenium (Se) contamination due to industrial activities has received increasing concerns. Phytoremediation has been suggested to be an efficient and feasible way to remove Se from Se-contaminated environment. Recently, an arsenic (As) hyperaccumulator Pteris vittata L. (Chinese Brake fern) was found to be a Se accumulator. This study was carried out to investigate Se accumulation mechanisms concentrating on antioxidant responses of this plant to six levels of selenite (0, 1, 2, 5, 10, and 20 mg/L). The results showed that Chinese Brake fern can accumulate a large amount of Se without any visible toxic symptoms and significant decreases in its biomass. However, the root took up more Se than the fronds. The highest concentration of Se in the roots and fronds was 1.536 mg/kg and 242 mg/kg, respectively, demonstrating a typical accumulation character to Se. Addition of 2 mg/L Se decreased, but &ge; 5&nbsp;mg/L Se enhanced the production of malondialdehyde (MDA), suggesting an antioxidant role of low dosages of Se. The enzymes of catalase (CAT), ascorbate peroxidase (APX) and peroxidase (POD) contributed their anti-oxidative functions only under low dosages of Se, as shown by their increased activities at Se levels &le; 5 mg/L and lowered activities at Se levels &gt; 5 mg/L. The concentration of glutathione (GSH) and enzyme activity of glutathione reductase (GR) were stimulated by &ge; 5 mg/L Se. Superoxide dismutase (SOD) activity was also enhanced by 20 mg/L Se. Our results suggest that SOD, GSH and GR were likely responsible for, but enzymes of POD, APX, and CAT have limited roles in Se accumulation in Chinese Brake fern. &nbsp;

scholarly journals Grasses suppress shoot-borne roots to conserve water during drought

2016 ◽  
Vol 113 (31) ◽  
pp. 8861-8866 ◽  
Author(s):  
Jose Sebastian ◽  
Muh-Ching Yee ◽  
Willian Goudinho Viana ◽  
Rubén Rellán-Álvarez ◽  
Max Feldman ◽  
...  
Keyword(s):  
Root Growth ◽  
Water Deficit ◽  
Water Availability ◽  
Water Status ◽  
Primary Root ◽  
Root Systems ◽  
Crop Productivity ◽  
Grass Species ◽  
Poaceae Family ◽  
Crown Roots

Many important crops are members of the Poaceae family, which develop root systems characterized by a high degree of root initiation from the belowground basal nodes of the shoot, termed the crown. Although this postembryonic shoot-borne root system represents the major conduit for water uptake, little is known about the effect of water availability on its development. Here we demonstrate that in the model C4 grass Setaria viridis, the crown locally senses water availability and suppresses postemergence crown root growth under a water deficit. This response was observed in field and growth room environments and in all grass species tested. Luminescence-based imaging of root systems grown in soil-like media revealed a shift in root growth from crown-derived to primary root-derived branches, suggesting that primary root-dominated architecture can be induced in S. viridis under certain stress conditions. Crown roots of Zea mays and Setaria italica, domesticated relatives of teosinte and S. viridis, respectively, show reduced sensitivity to water deficit, suggesting that this response might have been influenced by human selection. Enhanced water status of maize mutants lacking crown roots suggests that under a water deficit, stronger suppression of crown roots actually may benefit crop productivity.

scholarly journals Identification of an Isoflavonoid Transporter Required for the Nodule Establishment of the Rhizobium-Fabaceae Symbiotic Interaction

2021 ◽  
Vol 12 ◽  
Author(s):  
Wanda Biała-Leonhard ◽  
Laura Zanin ◽  
Stefano Gottardi ◽  
Rita de Brito Francisco ◽  
Silvia Venuti ◽  
...  
Keyword(s):  
Functional Characterization ◽  
Crop Productivity ◽  
Signaling Cascades ◽  
Nutritional Deficiencies ◽  
White Lupin ◽  
Symbiotic Interaction ◽  
Phosphate Availability ◽  
Rhizobial Symbiosis

Nitrogen (N) as well as Phosphorus (P) are key nutrients determining crop productivity. Legumes have developed strategies to overcome nutrient limitation by, for example, forming a symbiotic relationship with N-fixing rhizobia and the release of P-mobilizing exudates and are thus able to grow without supply of N or P fertilizers. The legume-rhizobial symbiosis starts with root release of isoflavonoids that act as signaling molecules perceived by compatible bacteria. Subsequently, bacteria release nod factors, which induce signaling cascades allowing the formation of functional N-fixing nodules. We report here the identification and functional characterization of a plasma membrane-localized MATE-type transporter (LaMATE2) involved in the release of genistein from white lupin roots. The LaMATE2 expression in the root is upregulated under N deficiency as well as low phosphate availability, two nutritional deficiencies that induce the release of this isoflavonoid. LaMATE2 silencing reduced genistein efflux and even more the formation of symbiotic nodules, supporting the crucial role of LaMATE2 in isoflavonoid release and nodulation. Furthermore, silencing of LaMATE2 limited the P-solubilization activity of lupin root exudates. Transport assays in yeast vesicles demonstrated that LaMATE2 acts as a proton-driven isoflavonoid transporter.

Medicago truncatula response to water-deficit stress: whole plant perspectives

2021 ◽  
Author(s):  
◽  
Verónica Castañeda Presa
Keyword(s):  
Water Deficit ◽  
Medicago Truncatula ◽  
Water Status ◽  
Water Deficit Stress ◽  
World Population ◽  
Fibrous Root ◽  
Model Plant ◽  
Whole Plant ◽  
Plant Level

Medicago truncatula is a forage legume with agricultural but also scientifical interest, being used as a model plant for the study of legumes’ biology. Within a climate change context, it is of great importance to maintain/increase plant yield in stressful growth conditions to meet the requirements of the increasing world population. In order to achieve this, it is mandatory to further understand the adaptive response of plants to water-deficit stress, for which the use of this model plant results of great utility. In the present study, the simultaneous study of various plant organs with particular focus on the root system allows us a more integrative understanding of water-deficit response mechanisms from a whole-plant perspective. The root tissue was studied in Chapter 1, distinguishing between the thick taproot and the much thinner fibrous root. The different behaviour of both root types under well-watered as well as under water-deficit conditions was studied from a physiological and metabolic perspec-tive. This study highlighted the active role of the taproot rather than being considered a mere nutrient storage organ. The taproot showed a more resilient nature towards water-deficit stress than the fibrous root, while sucrose cleavage modulation, together with proline metabolism sug-gested a crucial role of these pathways in the root adaptation to water-deficit stress. In Chapter 2 we aimed to address different water-deficit conditions that can affect plant water status, using iso-osmotical conditions of salinity (NaCl and KCl), lack of irrigation and an osmoticum (PEG). This approach allows us to identify the similarities and differences in the mechanisms involved in the response to each stress at the whole-plant level. While PEG was dismissed as a reliable drought-stress mimicker, NaCl and KCl led to similar responses, with a slightly higher negative effect of KCl on plant metabolism. On the other hand, an emphasis on the shoot and root protection was observed for NaCl and no-irrigation stress, respectively. The study of the phloem sap allowed us to better understand the responses to the different water-deficit conditions at a whole-plant level. In summary, this study provides further insight into the response at the whole-plant level of M. truncatula to water-deficit conditions from a biochemical, metabolic and physiological point of view.

scholarly journals Photochemical and Antioxidant Responses in the Leaves of Xerophyta viscosa Baker and Digitaria sanguinalis L. under Water Deficit

2005 ◽  
Vol 60 (5-6) ◽  
pp. 435-443 ◽  
Author(s):  
Yasemin Ekmekci ◽  
Andreas Bohms ◽  
Jennifer A. Thomson ◽  
Sagadevan G. Mundree
Keyword(s):  
Oxidative Damage ◽  
Water Deficit ◽  
Chlorophyll A ◽  
Photosynthetic Pigment ◽  
Photochemical Efficiency ◽  
Digitaria Sanguinalis ◽  
Protective Mechanisms ◽  
Sod Activity ◽  
Antioxidant Responses ◽  
Photochemical Efficiency Of Psii

In this study, photochemical and antioxidant responses of the monocotyledonous resurrection plant Xerophyta viscosa Baker and the crab grass Digitaria sanguinalis L. under water deficit were investigated as a function of time. Water deficit was imposed by withholding irrigation for 21 d. Gas exchange and chlorophyll a fluorescence analyses indicated that the dehydration treatment caused photoinhibition in both species. The reduction in the photosynthesis rate in both species during water deficit probably contributed to the decline in the photochemical efficiency of PSII and electron transport rate. However, the stomatal conductance of both species did not change during treatment whereas the intercellular CO2 pressure increased after 10 d of water deficit treatment. These observations could be related to nonstomatal limitations. The increasing net transpiration rate of both species may have contributed to leaf cooling because of water limitations. Prolonged water deficit resulted in photosynthetic pigment chlorophyll (a + b) and carotenoids content loss in only D. sanguinalis. Both species especially D. sanguinalis had increased the level of anthocyanin after 15 d of treatment, possibly to prevent the damaging effect of photooxidation. The total SOD activity of D. sanguinalis was significantly different from X. viscosa during the treatment. The total peroxidase activity in D. sanguinalis was significantly higher than in X. viscosa. X. viscosa acclimated to water deficit with no ultimate apparent oxidative damage due to endogenous protective mechanisms of resurrection. In case of D. sanguinalis, water deficit induced considerable stress and possibly caused some oxidative damage, despite the upregulation of protection mechanisms.

Digital x-ray mapping of nanometer-size supported bimetallic catalysts

1988 ◽  
Vol 46 ◽  
pp. 530-531
Author(s):  
L. T. Germinario
Keyword(s):  
Background Radiation ◽  
Metal Cluster ◽  
Single Element ◽  
Beam Diameter ◽  
X Rays ◽  
X Ray ◽  
Major Interest ◽  
Induced Changes

Understanding the role of metal cluster composition in determining catalytic selectivity and activity is of major interest in heterogeneous catalysis. The electron microscope is well established as a powerful tool for ultrastructural and compositional characterization of support and catalyst. Because the spatial resolution of x-ray microanalysis is defined by the smallest beam diameter into which the required number of electrons can be focused, the dedicated STEM with FEG is the instrument of choice. The main sources of errors in energy dispersive x-ray analysis (EDS) are: (1) beam-induced changes in specimen composition, (2) specimen drift, (3) instrumental factors which produce background radiation, and (4) basic statistical limitations which result in the detection of a finite number of x-ray photons. Digital beam techniques have been described for supported single-element metal clusters with spatial resolutions of about 10 nm. However, the detection of spurious characteristic x-rays away from catalyst particles produced images requiring several image processing steps.

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