scholarly journals Free proline accumulation in sugarcane under water restriction and spittlebug infestation

2008 ◽  
Vol 65 (6) ◽  
pp. 628-633 ◽  
Author(s):  
Eduardo Rossini Guimarães ◽  
Miguel Angelo Mutton ◽  
Márcia Justino Rossini Mutton ◽  
Maria Inês Tiraboschi Ferro ◽  
Gisele Cristina Ravaneli ◽  
...  
Keyword(s):  
Water Deficit ◽  
Xylem Sap ◽  
Compatible Solutes ◽  
Water Shortage ◽  
Saccharum Officinarum ◽  
Dry Mass ◽  
Proline Accumulation ◽  
Free Proline ◽  
Water Restriction ◽  
Root Cells

Mahanarva fimbriolata (Stål) (Hemiptera: Cercopidae) has become a key pest in the sugarcane (Saccharum officinarum) fields of center-south Brazil. Although some control technologies have shown to be efficient, the damage promoted by this spittlebug species and its interaction with sugarcane are poorly characterized. At high infestation levels the symptoms are similar to those of severe water restriction. This work was conducted to determine whether the stress promoted by spittlebug infestation can be measured in terms of free proline accumulation. The water restriction tolerance of two sugarcane genotypes was also compared. Two experiments were set up in a greenhouse and arranged in a completely randomized design in a 2 x 2 x 4 factorial, with two cultivars (SP80-1816 and RB72454), two stress levels (control and ten nymphs per plant or 50% water restriction), and four sampling dates. The water deficit caused by spittlebug nymphs sucking xylem sap does not result in proline accumulation, illustrating that there are different mechanisms to sense when the water deficit is caused by insect feeding or water potential variation in root cells. The cultivar RB72454 accumulates more free-proline, and the dry mass accumulation and stalk growth are less affected in this cultivar under water restriction. The levels of compatible solutes probably cannot be used to measure spittlebug infestation stress in sugarcane and RB72454 is more tolerant to water shortage than SP80-1816.

scholarly journals DIVERSE STRATEGIES OF RHODODENDRON (Rhododendron sp.) GENOTYPES IN THE WATER SHORTAGE MANAGEMENT

2020 ◽  
Vol 19 (3) ◽  
pp. 159-165
Author(s):  
Peter Ferus ◽  
Dominika Bošiaková ◽  
Jana Konôpková ◽  
Peter Hoťka
Keyword(s):  
Climate Change ◽  
Drought Resistance ◽  
Water Shortage ◽  
Proline Accumulation ◽  
The Other ◽  
Summer Drought ◽  
Free Proline ◽  
Resistance Strategies ◽  
Relative Water ◽  
Leaf Relative Water Content

Rhododendrons in numerous gardens in Central Europe are frequently endangered by adverse summer drought periods associated with the climate change. Therefore, in this work drought-resistance strategies in recent genotypes of these highly aesthetic shrubs were investigated. Dehydrated Rhododendron groenlandicum ‘Helma’, R. obtusum ‘Michiko’ and R. hybridum ‘Polarnacht’ showed high initial stomatal conductances (gS), after few days steeply falling to the stable minimum at ca. 20, 85 and 70% leaf relative water content (RWC), respectively. Except of ‘Polarnacht’, they had relatively large specific leaf area and ‘Michiko’ also free proline accumulation. On the other hand, R. repens ‘Scarlet Wonder’ and R. hybridum ‘Red Jack’ started with half gS values, continuously declining 1.5–2 fold longer compared to the first group of genotypes (RWC of ca. 60 and 75%, respectively). Both produced relatively thick leaves but did not show any osmotic adjustment. Among observed drought-resistance strategies, lower and longer period active transpiration with stomata sensitive to the water loss, as found in R. repens ‘Scarlet Wonder’ and R. × hybridum ‘Red Jack’, were accepted as the most effective for drought-affected rhododendron plantations.

Physiological Aspects of Racomitrium crispipilum Taylor A. (Jaeger) during Dry Season in Páramo de Chingaza, Colombia

2009 ◽  
Vol 30 (1) ◽  
pp. 1-7
Author(s):  
Andrés Felipe Barón ◽  
Walther García ◽  
Luz Marina Melgarejo ◽  
Luis Carlos Montenegro
Keyword(s):  
Water Deficit ◽  
Soluble Protein ◽  
Water Shortage ◽  
Dry Mass ◽  
Dry Season ◽  
Mountain Range ◽  
Relative Water ◽  
The Hours ◽  
Peroxidase Enzyme ◽  
Response To Water

In order to study the response to water deficit of the moss Racomitrium crispipilum (Taylor) A. Jaeger, a bryophyte typical of open sites and expose to water shortage, measurements of its soluble protein and proline contents, and enzymatic activity of catalase and peroxidase were made. Sampling was done in the Páramo de Chingaza, eastern mountain range of Colombia, in the zone of Lagunas de Buitrago during the dry season. We determined that R. crispipilum diminish its relative water content (RWC) from 50% to 4% of its dry mass (DM) (i.e. to <10% of its capacity), without losing the ability to synthesize proteins in the rehydration. Declining RWC was associated with declining soluble protein content and increased activities of catalase and peroxidase. Enzyme activities peacked in the hours at which R. crispipilum exhibited its minimum RWC (21.02 U mg protein-1 min-1 for catalase and 172.66 for peroxidase). Proline was found to be high during the hours of maximum RWC and the earliest hours of diminishing RWC, between 60 and 87.07 mg g dry mass-1 and declines to 18.98 during the afternoon. The results reported in this study give the first evidence that the activities of catalase and peroxidase increase in this species in response to conditions of water deficit. This is likely to be an important component in the mechanism by which this moss tolerates drought periods.

scholarly journals Weed Growth and Dry Matter Partition Under Water Restriction

2016 ◽  
Vol 34 (4) ◽  
pp. 701-708 ◽  
Author(s):  
M.F.P. LIMA ◽  
J.L.D. DOMBROSKI ◽  
F.C.L. FREITAS ◽  
J.R.S. PINTO ◽  
D.V. SILVA
Keyword(s):  
Leaf Area ◽  
Water Deficit ◽  
Dry Matter ◽  
Dry Mass ◽  
Water Restriction ◽  
Weed Species ◽  
Commelina Benghalensis ◽  
Weed Growth ◽  
Cultivated Species ◽  
Number Of Leaves

ABSTRACT The capacity of a weed to adapt to the restriction of growth factors is directly related to its ability to compete for those resources with the cultivated species. An experiment was conducted to evaluate the effect of water restriction on the growth and biomass partitioning of four species of weeds. The experimental design used randomized blocks, with five replications. The treatments were arranged in a 4 x 2 factorial, with the first factor being the weed species (Waltheria indica, Crotalaria retusa, Cleome affinis and Commelina benghalensis) and the second, two water regimes: daily irrigation (Irr) and water restriction (WR). The number of leaves, leaf area, dry mass of the plant and its parts (root, stem and leaf), and the mass distribution among different organs (roots, leaves and stems) were determined. The water deficit in the soil increased the root dry matter for C. retusa, W. indica and C. benghalensis, however, it did not alter the mass of the stem of the weeds. C. retusa and W. indica suffered a reduction on the number of leaves, leaf area, dry matter of the leaves and the plant dry matter under water deficit. W. indica and C. retusa had a reduction on the percentage of biomass allocated to the leaves, and an increment on the percentage of the roots mass, while C. benghalensis and C. affinis had an increase only on the roots mass.

scholarly journals Traditional Varieties of Caupi Submitted to Water Deficit: Physiological and Biochemical Aspects

2019 ◽  
Vol 11 (6) ◽  
pp. 424
Author(s):  
Bruno do Nascimento Silva ◽  
Stelamaris de Oliveira Paula ◽  
Joniele Vieira de Oliveira ◽  
Johny de Souza Silva ◽  
Cândida Hermínia Campos de Magalhães ◽  
...  
Keyword(s):  
Water Deficit ◽  
Water Shortage ◽  
Photochemical Quenching ◽  
Family Farms ◽  
Water Restriction ◽  
High Accumulation ◽  
Brazilian Semiarid ◽  
Severe Water Deficit ◽  
Total Carbohydrates ◽  
Physiological And Biochemical

The cowpea (Vigna unguiculata (L.) Walp) it is a leguminous widely cultivated in Northeast of Brazil. In the state of Ceara, its cultivation is performed mainly by family farms who make use of traditional varieties of good adaptation to the growing region. Thus, characterizing traditional varieties with characteristics of adaptation to regions with water shortage is essential for the production of food in the world, especially in semi-arid regions. In this sense, the objective was to evaluate the physiological and biochemical responses in three genotypes of cowpea, being two traditional varieties grown in Ceara (Sempre-Verde and Cabe&ccedil;a-de-Gato) and a genotype characterized as a standard of drought tolerance (Pingo-de-Ouro-1,2) under three water regimes: irrigated, moderate deficit and severe water deficit. The parameters evaluated were: gas exchange, chlorophyll a fluorescence, photosynthetic pigments, organic solutes (proline, total carbohydrates, reducing and non-reducing carbohydrates), starch and enzyme activity (APX, G-POD, CAT and SOD). The genotype Pingo-de-Ouro-1,2 confirmed its tolerance pattern in a water deficit condition, presenting greater water potential, higher photosynthetic rate, high levels of total carbohydrates and high accumulation of proline. Among the traditional varieties, the Cabe&ccedil;a-de-Gato presented superior photosynthesis to Sempre-Verde higher Electron Transport Rate (ETR), reflecting in a greater photochemical quenching (qP) and a greater accumulation of proline, indicating that this variety presents more pronounced adaptive characteristics for water restriction conditions, which is a common condition to the Brazilian semiarid.

scholarly journals New approaches to the action of silicon to enable the cultivation of Panicum maximum in soil with water restriction

2021 ◽  
Author(s):  
Juan Ricardo Rocha ◽  
Renato Mello Prado ◽  
Marisa Cássia Piccolo
Keyword(s):  
Water Content ◽  
Water Deficit ◽  
Physiological Stress ◽  
Antioxidant Defense System ◽  
Dry Mass ◽  
Water Retention Capacity ◽  
Panicum Maximum ◽  
Water Restriction ◽  
Retention Capacity ◽  
C And N

Abstract Climate change increases the occurrence of droughts, decreasing the production of tropical forages through the induction of physiological stress. Si is expected to broaden the limit from physiological stress of forages grown under water restriction, which may come from an improvement in the stoichiometric homeostasis of Si with N and C, favoring physiological aspects. This study assessed whether Si supply via fertigation improves physiological aspects and the water content in the plant by means of an antioxidant defense system and changes in the C:N:Si stoichiometry during the regrowth of two cultivars of Panicum maximum grown under two soil water regimes (70 and 40% of the soil’s water retention capacity). The forages studied are sensitive to water deficit without silicon supply. The application of Si via fertigation attenuated the water deficit, favoring plant growth by stabilizing the stoichiometric homeostasis C:N and C:Si, which are responsible for increasing the plant capacity of converting accumulated C in dry mass, favoring the water content of the plant tissue and the photosynthetic efficiency. This study highlights the importance of the physiological function of Si, and effects on the stoichiometry of C and N, which are neglected in most research on forages grown under water restriction.

A study of membrane lipids from dehydration-acclimated Brassica napus root cells: formation of a cubic phase under physiological conditions

1990 ◽  
Vol 68 (1) ◽  
pp. 102-105 ◽  
Author(s):  
P. Norberg ◽  
K. Larsson ◽  
C. Liljenberg
Keyword(s):  
Water Deficit ◽  
Membrane Lipids ◽  
Phase Behaviour ◽  
Water Deficit Stress ◽  
Cubic Phase ◽  
Polarization Microscopy ◽  
Root Cells ◽  
X Ray ◽  
X Ray Crystallography ◽  
Microsomal Membranes

Rape seedlings were acclimated to evaporative dehydration by exposure to repeated moderate water-deficit stress. The stress program started after 19 days of growth and consisted of three, 24-h stress periods interspersed with 24-h rewatering periods. After the third stress period the roots were harvested and microsomal membranes were isolated. Control plants were grown under equivalent conditions without stress (nonacclimated cells). Total lipids were extracted from the membranes and investigated with X-ray crystallography and polarization microscopy at different degrees of hydration and temperatures. In excess water, the membrane lipids from both acclimated and nonacclimated cells exhibited a cubic phase. The lipids from the nonacclimated cells formed a hexagonal (HII) phase on dehydration. The lipids from the acclimated cells behaved in a different way during dehydration, where the cubic phase was transformed to an L2 phase via an intermediate HII phase. At increasing temperatures, the hydrated cubic phase started to form an L2 phase at 30 °C and was fully converted to the liquid-type state at 42 °C. The mesomorphic phase behaviour is discussed in relation to membrane activity.Key words: water-deficit stress, microsomal membranes, X-ray crystallography, polarization microscopy.

De novo protein synthesis in relation to ammonia and proline accumulation in water stressed white clover

2004 ◽  
Vol 31 (8) ◽  
pp. 847 ◽  
Author(s):  
Tae-Hwan Kim ◽  
Bok-Rye Lee ◽  
Woo-Jin Jung ◽  
Kil-Yong Kim ◽  
Jean-Christophe Avice ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Water Deficit ◽  
White Clover ◽  
De Novo ◽  
Proline Accumulation ◽  
Leaf Water ◽  
Total N ◽  
Water Parameters ◽  
Leaves And Roots ◽  
De Novo Protein Synthesis

The kinetics of protein incorporation from newly-absorbed nitrogen (N, de novo protein synthesis) was estimated by 15N tracing in 18-week-old white clover plants (Trifolium repens L. cv. Regal) during 7 d of water-deficit treatment. The physiological relationship between kinetics and accumulation of proline and ammonia in response to the change in leaf-water parameters was also assessed. All leaf-water parameters measured decreased gradually under water deficit. Leaf and root dry mass was not significantly affected during the first 3 d when decreases in leaf-water parameters were substantial. However, metabolic parameters such as total N, proline and ammonia were significantly affected within 1 d of commencement of water-deficit treatment. Water-deficit treatment significantly increased the proline and NH3–NH4+ concentrations in both leaves and roots. There was a marked reduction in the amount of N incorporated into the protein fraction from the newly absorbed N (NANP) in water-deficit stressed plants, particularly in leaf tissue. This reduction in NANP was strongly associated with an increased concentration of NH3–NH4+ in roots (P≤0.05) and proline (P≤0.01) in leaves and roots. These results suggest that proline accumulation may be a sensitive biochemical indicator of plant water status and of the dynamics of de novo protein synthesis in response to stress severity.

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