scholarly journals Endoproteinase activities in wheat leaves upon water deficit.

1996 ◽  
Vol 43 (3) ◽  
pp. 515-519 ◽  
Author(s):  
B Zagdańska ◽  
K Wiśniewski
Keyword(s):  
Water Deficit ◽  
Cysteine Proteinase ◽  
Ph Dependence ◽  
Serine Proteinase ◽  
Aspartic Proteinase ◽  
Water Deficiency ◽  
Drought Conditions ◽  
Wheat Leaves

In wheat leaves acclimated and non-acclimated to water deficit the azocaseinolytic activities of endoproteinases were increased about 7-fold under drought conditions. Under such conditions both the pH dependence profile and the endoproteinase pattern were also changed. The predominant contribution of serine proteinase (about 50% of total endoproteinase activity) remains unaltered in the drought stressed leaves. Cysteine proteinase was induced to the same extent in the drought-stressed leaves irrespective of the acclimation pretreatment, while the contribution of aspartic proteinase was reduced upon water deficit but in the acclimated stressed leaves was as high as in the non-stressed leaves. These changes in the pattern of endoproteinases seem to imply that the water deficiency affects endogenous proteolysis.

Expression and Inhibition Analysis of Recombinant Protease Inhibitor of Solamum Americanum in E. Coli

2011 ◽  
Vol 343-344 ◽  
pp. 1053-1058
Author(s):  
Zhen Yu Wang ◽  
Jia Li ◽  
Min Zhe Li ◽  
Tong Cun Zhang
Keyword(s):  
Cysteine Proteinase ◽  
Serine Proteinase ◽  
Competitive Inhibitor ◽  
Inhibitory Effect ◽  
Aspartic Proteinase ◽  
E Coli ◽  
Solanum Americanum ◽  
Strong Inhibitory Effect ◽  
Noncompetitive Inhibitor ◽  
Inhibition Analysis

SaPIN2a, the proteinase inhibitor of nightshade (Solanum americanum), has been proposed to regulate proteolysis in phloem development. In this study, we expressed and characterized recombinant SaPIN2a in Escherichia coli. Purified recombinant SaPIN2a (rSaPIN2a) had a strong inhibitory effect on serine proteinase chymotrypsin (IC50 36.1 nmol/L), but its inhibitory activities toward trypsin (IC50 398.6 nmol/L) and especially toward subtilisin (IC50 5004 nmol/L) were low. It did not inhibit cysteine proteinase papain and aspartic proteinase cathepsin D. rSaPIN2a was a competitive inhibitor of trypsin, and a noncompetitive inhibitor of chymotrypsin and subtilisin.

Rate of Photosynthesis and Transpiration of Winter Wheat Leaves and Ears Under Water Deficit Conditions

2008 ◽  
Vol 23 (2) ◽  
pp. 326-335
Author(s):  
Jacek Olszewski ◽  
Agnieszka Pszczółkowska ◽  
Tomasz Kulik ◽  
Gabriel Fordoński ◽  
Krystyna Płodzień ◽  
...  
Keyword(s):  
Winter Wheat ◽  
Water Deficit ◽  
Rate Of Photosynthesis ◽  
Wheat Leaves

scholarly journals Overexpression of MdATG8i improves water use efficiency in transgenic apple by modulating photosynthesis, osmotic balance, and autophagic activity under moderate water deficit

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Xin Jia ◽  
Ke Mao ◽  
Ping Wang ◽  
Yu Wang ◽  
Xumei Jia ◽  
...  
Keyword(s):  
Water Use Efficiency ◽  
Water Deficit ◽  
Water Use ◽  
Photosynthetic Capacity ◽  
Critical Role ◽  
Drought Conditions ◽  
Moderate Drought ◽  
Use Efficiency ◽  
Autophagic Activity

AbstractWater deficit is one of the major limiting factors for apple (Malus domestica) production on the Loess Plateau, a major apple cultivation area in China. The identification of genes related to the regulation of water use efficiency (WUE) is a crucial aspect of crop breeding programs. As a conserved degradation and recycling mechanism in eukaryotes, autophagy has been reported to participate in various stress responses. However, the relationship between autophagy and WUE regulation has not been explored. We have shown that a crucial autophagy protein in apple, MdATG8i, plays a role in improving salt tolerance. Here, we explored its biological function in response to long-term moderate drought stress. The results showed that MdATG8i-overexpressing (MdATG8i-OE) apple plants exhibited higher WUE than wild-type (WT) plants under long-term moderate drought conditions. Plant WUE can be increased by improving photosynthetic efficiency. Osmoregulation plays a critical role in plant stress resistance and adaptation. Under long-term drought conditions, the photosynthetic capacity and accumulation of sugar and amino acids were higher in MdATG8i-OE plants than in WT plants. The increased photosynthetic capacity in the OE plants could be attributed to their ability to maintain optimal stomatal aperture, organized chloroplasts, and strong antioxidant activity. MdATG8i overexpression also promoted autophagic activity, which was likely related to the changes described above. In summary, our results demonstrate that MdATG8i-OE apple lines exhibited higher WUE than WT under long-term moderate drought conditions because they maintained robust photosynthesis, effective osmotic adjustment processes, and strong autophagic activity.

scholarly journals Drought Adaptation in Fuchsia magellanica and Its Effect on Freezing Tolerance

2008 ◽  
Vol 133 (1) ◽  
pp. 11-19 ◽  
Author(s):  
Majken Pagter ◽  
Karen K. Petersen ◽  
Fulai Liu ◽  
Christian R. Jensen
Keyword(s):  
Water Potential ◽  
Water Deficit ◽  
Freezing Tolerance ◽  
Woody Plants ◽  
Xylem Sap ◽  
Water Deficiency ◽  
Frost Injury ◽  
Different Types ◽  
Curvilinear Relation ◽  
Reduced Water

Fuchsia (Fuchsia L.) is a popular woody ornamental, but it is very susceptible to frost injury during winter. As drought stress may be used to enhance freezing tolerance in woody plants, the effects of different types of water deficit on growth, selected physiological traits, and freezing tolerance were examined in Fuchsia magellanica Lam. ‘Riccartonii’. Drought responses were investigated after 6 weeks of pretreatment, where individual plants grown in a greenhouse under conditions of unrestricted water supply were compared with plants subjected to cyclic or continuous water deficit. After an additional 4 weeks of treatment at short day (10 h) and low temperature (8 °C day/4 °C night), freezing tolerance was examined. Both continuous and cyclic water deficit plants reduced water loss by reducing aboveground biomass and by efficient stomatal regulation. Continuous water deficit plants tended to adjust osmotically, while cyclic water deficit induced significantly higher xylem sap abscisic acid [(ABA)xylem] and leaf proline concentrations and a lower leaf water potential (ψl) than continuous water deficit, indicating that F. magellanica responds differently to continuous water deficit and to fast drying associated with stress phases of cyclic water deficit. The root water potential (ψr) and (ABA)xylem were negatively linearly correlated, implying that increasing water deficiency stimulated formation of ABA in the roots. An inverse, curvilinear relation between (ABA)xylem and stomatal conductance (g s) indicated that root-originated ABA might control g s during mild water deficits. Neither cold-acclimating conditions alone nor combined with water deficit increased stem freezing tolerance, indicating that F. magellanica lacks cold-acclimation ability under the inductive conditions used in this study.

scholarly journals Mutations in the tomato gibberellin receptors suppress xylem proliferation and reduce water loss under water-deficit conditions

2020 ◽  
Vol 71 (12) ◽  
pp. 3603-3612 ◽  
Author(s):  
Natanella Illouz-Eliaz ◽  
Idan Nissan ◽  
Ido Nir ◽  
Uria Ramon ◽  
Hagai Shohat ◽  
...  
Keyword(s):  
Water Deficit ◽  
Water Status ◽  
Stomatal Closure ◽  
Normal Growth ◽  
Hydraulic Conductance ◽  
Xylem Vessel ◽  
Leaf Water Content ◽  
Whole Plant ◽  
Drought Conditions ◽  
Better Than

Abstract Low gibberellin (GA) activity in tomato (Solanum lycopersicum) inhibits leaf expansion and reduces stomatal conductance. This leads to lower transpiration and improved water status under transient drought conditions. Tomato has three GIBBERELLIN-INSENSITIVE DWARF1 (GID1) GA receptors with overlapping activities and high redundancy. We tested whether mutation in a single GID1 reduces transpiration without affecting growth and productivity. CRISPR-Cas9 gid1 mutants were able to maintain higher leaf water content under water-deficit conditions. Moreover, while gid1a exhibited normal growth, it showed reduced whole-plant transpiration and better recovery from dehydration. Mutation in GID1a inhibited xylem vessel proliferation, which led to lower hydraulic conductance. In stronger GA mutants, we also found reduced xylem vessel expansion. These results suggest that low GA activity affects transpiration by multiple mechanisms: it reduces leaf area, promotes stomatal closure, and reduces xylem proliferation and expansion, and as a result, xylem hydraulic conductance. We further examined if gid1a performs better than the control M82 in the field. Under these conditions, the high redundancy of GID1s was lost and gid1a plants were semi-dwarf, but their productivity was not affected. Although gid1a did not perform better under drought conditions in the field, it exhibited a higher harvest index.

Water Relations in Young Growing Wheat Leaves after Application of (2-Chloroethyl)trimethyl- ammoniumchloride (CCC) to the Roots of Wheat Seedlings

1985 ◽  
Vol 40 (9-10) ◽  
pp. 745-747
Author(s):  
Jutta Bode ◽  
Aloysius Wild
Keyword(s):  
Water Relations ◽  
Reducing Sugars ◽  
Triticum Aestivum L ◽  
Water Deficiency ◽  
Pressure Potential ◽  
Tissue Water ◽  
Wheat Seedlings ◽  
Diffusive Resistance ◽  
Wheat Leaves ◽  
Synthetic Growth

Abstract The influence on the water relations of the third developing leaf of (2-chloroethyl)trimethylammoniumchloride, a synthetic growth regulator, applied to the roots of young wheat plants (Triticum aestivum L.) has been investigated. The tissue water potential and the pressure potential were found to be reduced by several bars in comparison to the untreated controls, whereas the osmotic potential remained unchanged. The content of soluble reducing sugars was considerably increased in the cell sap of CCC-treated leaves. With this accumulation, however, the turgor was not maintained. Additionally, CCC-treated leaves showed considerably lower transpiration rates and higher diffusive resistance than the controls. Thus, the application of CCC to the roots causes alterations in the water relations of developing wheat leaves, which resemble those induced by water deficiency.

scholarly journals Gas exchange alteration caused by water deficit during the bean reproductive stage

2010 ◽  
Vol 14 (1) ◽  
pp. 11-16 ◽  
Author(s):  
Lauricio Endres ◽  
José L. de Souza ◽  
Iedo Teodoro ◽  
Paula M. G. Marroquim ◽  
Claudiana M. dos Santos ◽  
...  
Keyword(s):  
Water Deficit ◽  
Crop Productivity ◽  
Vegetative Stage ◽  
Water Deficiency ◽  
Phaseolus Vulgaris L ◽  
Physiological Factors ◽  
Gas Exchanges ◽  
Grain Productivity ◽  
Entire Plant ◽  
Phase Water

The purpose of the present study was to analyze gas exchanges in leaves and the parameters of productivity of beans (Phaseolus vulgaris, L.) submitted to two water deficiency periods during which three water regimes were employed: W1 (1,0 ETo during the entire plant cycle); W2 (1,0 ETo up to the flowering period and irrigation interruption from the 37 to the 51st day following sowing, and W3 (in addition to the reproductive phase, water deficit was also applied during the vegetative stage). Photosynthesis was one of the main physiological factors affected by water deficit. This was not only caused by the stomata closure, but also by carboxilation reduction due to metabolic damage. This effect was, however, offset 24 h after rehydration. During flowering, the water deficit caused crop productivity to drop significantly, reducing the number of pods and the number of seeds per pod, independently of the water deficit during the vegetative stage. The weight of 100 seeds however, was the same regardless of treatment. These results suggest that the water deficit caused the reduction of photo-assimilates, which affected grain productivity. Nevertheless, once properly formed, seeds developed totally; a strategy of the plant to produce less seeds under stress, but viable to perpetuate the species.

scholarly journals Consequences of Seed Priming with Salicylic Acid and Hydro Priming on Smooth Vetch Seedling Growth under Water Deficiency

2017 ◽  
Vol 9 (12) ◽  
pp. 259
Author(s):  
Amin Namdari ◽  
Abolfazl Baghbani
Keyword(s):  
Salicylic Acid ◽  
Water Deficit ◽  
Seedling Growth ◽  
Glycine Betaine ◽  
Soluble Sugars ◽  
Early Growth ◽  
Water Deficit Stress ◽  
Growth Stages ◽  
Water Deficiency ◽  
Available Water

Due to low rainfall at early autumn, smooth vetch seedling growth in rain-fed lands often is limited by water deficit stress yet the data regarding the reactions of smooth vetch to water deficit at early growth stages are pretty rare. The objective of current study was to examine possibility of using priming treatments (hydro priming and priming salicylic acid) to alleviate the inhibitory effect of water deficiency during early growth of Smooth Vetch. In this respect, seeds were soaked in distilled water (hydro priming) or 0.5 mM solution of SA for 36 h at 10 °C then dried back to original moisture content. Pots were irrigated for 25 days at four levels of available water containing field capacity (FC), 75% FC, 50% FC and 25% FC. In general, seedling emergence and early growth were markedly limited by increasing water deficiency. However, priming treatments particularly with SA caused considerable improvement in either emergence or growth of seedlings (dry weight, length). The obtained results showed that primed samples exhibited higher accumulation of proline, glycine betaine (GB) under all levels of available water except 100% FC and also higher total soluble sugars (TSS) and trehalose under severe water deficit (25% FC). SA primed samples had higher relative water content especially under higher levels of water deficiency. The more balanced water status within SA primed samples also was accompanied with higher accumulation of proline and glycine betaine. There were significant differences between two priming treatments in terms of proline and GB content within seedlings and SA priming considerably increased proline and GB accumulation. In contrast to proline and GB, TSS and trehalose content wasn’t influenced by SA treatment and both hydro and SA primed samples showed statistically similar quantities.

scholarly journals Shading as a means of mitigating water deficit in seedlings of Campomanesia xanthocarpa (Mart.) O. Berg

2020 ◽  
Vol 48 (1) ◽  
pp. 234-244
Author(s):  
Edinéia M.M. BARTIERES ◽  
Silvana P.Q. SCALON ◽  
Daiane M. DRESCH ◽  
Edvânia A.S. CARDOSO ◽  
Mailson V. JESUS ◽  
...  
Keyword(s):  
Water Content ◽  
Water Deficit ◽  
Relative Water Content ◽  
Growth Characteristics ◽  
Water Deficiency ◽  
Cultivation Conditions ◽  
Continuous Irrigation ◽  
Intermittent Irrigation ◽  
Relative Water ◽  
Number Of Leaves

In this research it was hypothesized that Campomanesia xanthocarpa can overcome some level of water deficiency by adjusting physiological parameters and that shading minimizes the water deficit effects while maintaining elevated photosynthetic rates and relative water content of the leaves and makes a resumption of metabolism and growth when the water supply is normalized. The seedlings were submitted to two water regimes (continuous irrigation - CI and intermittent irrigation - II), three shading percentages (0, 30 and 70%) and six evaluation times (Start - T0, 1st Photosynthesis Zero - 1st P0, 1st Recovery - 1st REC, 2nd Photosynthesis Zero - 2nd P0, 2nd Recovery - 2nd REC and END). Plants under water deficit at 0% shading led to a reduction in photosynthetic metabolism, relative water content (RWC), leaf area, number of leaves, and height, especially during the stress periods 1st and 2nd P0. The 30 and 70% shading mitigated the stressful effect of water deficit on C. xanthocarpa seedlings. The results did not confirm the hypothesis that C. xanthocarpa seedlings are intolerant to water deficit since, although sensitive, they presented a potential for recovery of photosynthetic and growth characteristics under all cultivation conditions. It was concluded that that shading minimizes the stressful effects of water deficit.

scholarly journals Proteolysis of ankyrin and of band 3 protein in chemically induced cell fusion. Ca2+ is not mandatory for fusion

1984 ◽  
Vol 218 (2) ◽  
pp. 295-305 ◽  
Author(s):  
R D A Lang ◽  
C Wickenden ◽  
J Wynne ◽  
J A Lucy
Keyword(s):  
Membrane Proteins ◽  
Lipid Bilayers ◽  
Cysteine Proteinase ◽  
Serine Proteinase ◽  
Band 3 ◽  
Human Erythrocytes ◽  
General Mechanism ◽  
Band 3 Protein ◽  
Fusion Reactions ◽  
Chlorpromazine Hydrochloride

Human erythrocytes were fused by incubation with 0.5-2 mM-chlorpromazine hydrochloride at pH 6.8-7.6. Fusogenic preparations of chlorpromazine were cloudy suspensions of microdroplets, and below pH 6.8 chlorpromazine gave clear solutions that were inactive. Unlike control cells, the lateral mobility of the intramembranous particles of the PF-fracture face of chlorpromazine-treated cells was relatively unrestricted, since the particles were partly clustered at 37 degrees C and they exhibited extensive cold-induced clustering. Ca2+ stimulated fusion, but fusion was only very weakly inhibited by EGTA (10 mM) and by N-ethylmaleimide (50 mM); pretreatment of the cells with Tos-Lys-CH2Cl (7-amino-1-chloro-3-L-tosylamidoheptan-2-one) (7.5 mM) markedly inhibited fusion. Changes in the membrane proteins of erythrocytes fused by chlorpromazine, before and after treatment with chymotrypsin to remove band 3 protein, were investigated. The several observations made indicate that the Ca2+-insensitive component of fusion is associated with degradation of ankyrin (band 2.1 protein) to band 2.3-2.6 proteins and to smaller polypeptides by a serine proteinase that is inhibited by Tos-Lys-CH2Cl, and that the component of fusion inhibited by EGTA and N-ethylmaleimide is associated with degradation of band 3 protein to band 4.5 protein by a Ca2+-activated cysteine proteinase. Proteolysis of ankyrin appeared to be sufficient to permit the chlorpromazine-induced fusion of human erythrocytes, but fusion occurred more rapidly when band 3 protein was also degraded in the presence of Ca2+. Since other cells have structures comparable with the spectrin-actin skeleton of the erythrocyte membrane, the observations reported may be relevant to the initiation of naturally occurring fusion reactions in biomembranes. It is also suggested that, should polypeptides with fusogenic properties be produced from integral and skeletal membrane proteins by endogenous proteolysis, their formation would provide a general mechanism for the fusion of lipid bilayers in biomembrane fusion reactions.

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