scholarly journals Leaf Senescence and Protein Metabolism in Creeping Bentgrass Exposed to Heat Stress and Treated with Cytokinins

2007 ◽  
Vol 132 (4) ◽  
pp. 467-472 ◽  
Author(s):  
Mahalaxmi Veerasamy ◽  
Yali He ◽  
Bingru Huang
Keyword(s):  
Heat Stress ◽  
Protein Content ◽  
Leaf Senescence ◽  
Protein Metabolism ◽  
Soluble Protein ◽  
Protease Activity ◽  
Creeping Bentgrass ◽  
Zeatin Riboside ◽  
Soluble Protein Content ◽  
Leaf Chlorophyll

Heat stress induces leaf senescence and causes changes in protein metabolism. The objective of this study was to investigate effects of exogenous application of a synthetic form of cytokinin, zeatin riboside (ZR), on protein metabolism associated with leaf senescence under heat stress for a cool-season grass species. Creeping bentgrass (Agrostis stolonifera L.) (cv. Penncross) plants were exposed to optimum temperature control (20/15 °C, day/night) and heat stress (35/30 °C) in growth chambers. Before heat stress treatments, foliage was sprayed with 10 μmol ZR or water (untreated) for 3 days and then once per week during 35 days of heat stress. Leaf chlorophyll content, photochemical efficiency (Fv/Fm), and soluble protein content declined, whereas protease activity increased during heat stress. Treatments with ZR helped maintain higher leaf chlorophyll content, Fv/Fm, and soluble protein content under heat stress. Protease activity in ZR-treated plants was lower than that of untreated plants. Zeatin riboside-treated plants had less severe degradation of ribulose-1,5-bisphosphate carboxylase proteins than untreated plants exposed to heat stress. In addition, ZR treatment upregulated the expression of 32- and 57-kDa proteins under heat stress conditions. These results demonstrated that the exogenous application of ZR ameliorated the negative effects of heat stress, as manifested by suppression or delay of leaf senescence. Cytokinins may have helped to alleviate heat stress injury, probably by slowing down the action of protease and by induction or upregulation of heat-shock proteins.

scholarly journals Heat-induced Leaf Senescence and Hormonal Changes for Thermal Bentgrass and Turf-type Bentgrass Species Differing in Heat Tolerance

2007 ◽  
Vol 132 (2) ◽  
pp. 185-192 ◽  
Author(s):  
Yan Xu ◽  
Bingru Huang
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Leaf Senescence ◽  
Heat Tolerance ◽  
Photochemical Efficiency ◽  
Creeping Bentgrass ◽  
Zeatin Riboside ◽  
Hormonal Changes ◽  
Heat Tolerant ◽  
Aba Content

Leaf senescence can be induced by many environmental stresses, including supraoptimal temperatures. The objectives of this study were to evaluate leaf senescence induced by heat stress for two Agrostis species contrasting in heat tolerance and to examine whether heat-induced leaf senescence in both species was associated with changes in three major senescence-related hormones: ethylene, abscisic acid (ABA), and cytokinins. Plants of heat-tolerant rough bentgrass (Agrostis scabra Willd.) and heat-sensitive creeping bentgrass (Agrostis stolonifera L.) were exposed to 35/30 °C (day/night) (high temperature) or 20/15 °C (control) for 35 d in growth chambers. Turf quality, photochemical efficiency (Fv/Fm), and the contents of two pigments (chlorophyll and carotenoid) for both species decreased under high temperature; however, heat-tolerant A. scabra exhibited delayed and less severe decline in all parameters compared with heat-sensitive A. stolonifera. Ethylene production rate increased in both species at 35 °C, but the increase was observed 21 days later in A. scabra compared with that in A. stolonifera. ABA content increased at the initiation of heat stress and then declined in both species after prolonged heat stress. However, the timing of the increase was delayed for 7 days and the highest level of ABA content was less in A. scabra (4.0 times that of the control) than that in A. stolonifera (5.9 times that of the control). Decreases in both forms of cytokinins (transzeatin/zeatin riboside and isopentenyl adenosine) were also delayed for 14 days and less pronounced in A. scabra. Correlation analysis revealed that leaf senescence induced by heat stress was negatively correlated to ethylene and ABA accumulation and positively correlated to cytokinin production. Delayed leaf senescence in A. scabra under heat stress could be related to slower and less magnitude of changes in ethylene, ABA, and cytokinins.

scholarly journals Changes in Protein Content, Protease Activity, and Amino Acid Content Associated with Heat Injury in Creeping Bentgrass

2005 ◽  
Vol 130 (6) ◽  
pp. 842-847 ◽  
Author(s):  
Yali He ◽  
Xiaozhong Liu ◽  
Bingru Huang
Keyword(s):  
Heat Stress ◽  
Amino Acid ◽  
Protein Content ◽  
Total Protein ◽  
Acid Content ◽  
Protease Activity ◽  
Amino Acid Content ◽  
Creeping Bentgrass ◽  
Total Protein Content ◽  
Turf Quality

Various physiological processes may deteriorate in response to increasing temperatures, contributing to the decline in turf quality for cool-season turfgrasses during heat stress. This study was performed to investigate metabolic changes (membrane lipid peroxidation, total protein content, amino acid content, and protease activity) associated with turf quality decline for creeping bentgrass (Agrostis stolonifera Huds.) in response to gradually increasing temperatures for a short duration and prolonged exposure to lethally high temperature. Plants were subjected to increasing temperatures of 20, 25, 30, 35, and 40 °C for 7 days at each level of temperature [gradual heat stress (GHS)] or exposed to high temperature of 40 °C for 28 days [prolonged heat stress (PHS)] in growth chambers. During the GHS treatment, significant decline in turf quality occurred when plants were exposed to 30 °C for 7 days; simultaneously, malondialdehyde (MDA) content increased and total protein content in shoots decreased significantly compared to those at 20 °C. Protease activity increased at 25 °C and then decreased as temperature was elevated from 30 to 40 °C during the GHS treatment. Amino acid content decreased under GHS, beginning at 25 °C. Under the PHS treatment, turf quality declined and MDA content increased significantly, beginning at 14 days of PHS, while total protein content decreased at 7 days of PHS. Protease activity and amino acid content increased at 7 days of PHS, and then declined with longer stress duration. Our results indicated that protease activity, and amino acid and total protein content were more responsive to GHS or PHS than that of lipid peroxidation and turf quality. Changes in metabolic parameters of protease activity, amino acid and total protein content, and lipid peroxidation may contribute to leaf senescence and poor turf performance under severe or prolonged heat stress conditions for creeping bentgrass.

scholarly journals Chitosan (CTS) Alleviates Heat-Induced Leaf Senescence in Creeping Bentgrass by Regulating Chlorophyll Metabolism, Antioxidant Defense, and the Heat Shock Pathway

Molecules ◽  
2021 ◽  
Vol 26 (17) ◽  
pp. 5337
Author(s):  
Cheng Huang ◽  
Yulong Tian ◽  
Bingbing Zhang ◽  
Muhammad Jawad Hassan ◽  
Zhou Li ◽  
...  
Keyword(s):  
Heat Stress ◽  
Heat Shock ◽  
Leaf Senescence ◽  
Heat Tolerance ◽  
Antioxidant Defense ◽  
Creeping Bentgrass ◽  
Grass Species ◽  
Antioxidant Enzyme Activities ◽  
Ros Scavenging ◽  
Chlorophyll Metabolism

Chitosan (CTS) is a deacetylated derivative of chitin that is involved in adaptive response to abiotic stresses. However, the regulatory role of CTS in heat tolerance is still not fully understood in plants, especially in grass species. The aim of this study was to investigate whether the CTS could reduce heat-induced senescence and damage to creeping bentgrass associated with alterations in antioxidant defense, chlorophyll (Chl) metabolism, and the heat shock pathway. Plants were pretreated exogenously with or without CTS (0.1 g L−1) before being exposed to normal (23/18 °C) or high-temperature (38/33 °C) conditions for 15 days. Heat stress induced detrimental effects, including declines in leaf relative water content and photochemical efficiency, but significantly increased reactive oxygen species (ROS) accumulation, membrane lipid peroxidation, and Chl loss in leaves. The exogenous application of CTS significantly alleviated heat-induced damage in creeping bentgrass leaves by ameliorating water balance, ROS scavenging, the maintenance of Chl metabolism, and photosynthesis. Compared to untreated plants under heat stress, CTS-treated creeping bentgrass exhibited a significantly higher transcription level of genes involved in Chl biosynthesis (AsPBGD and AsCHLH), as well as a lower expression level of Chl degradation-related gene (AsPPH) and senescence-associated genes (AsSAG12, AsSAG39, Asl20, and Ash36), thus reducing leaf senescence and enhancing photosynthetic performance under heat stress. In addition, the foliar application of CTS significantly improved antioxidant enzyme activities (SOD, CAT, POD, and APX), thereby effectively reducing heat-induced oxidative damage. Furthermore, heat tolerance regulated by the CTS in creeping bentgrass was also associated with the heat shock pathway, since AsHSFA-6a and AsHSP82 were significantly up-regulated by the CTS during heat stress. The potential mechanisms of CTS-regulated thermotolerance associated with other metabolic pathways still need to be further studied in grass species.

scholarly journals Effects of Water Particles in the Jinjiang River Estuary on the Physiological and Biochemical Characteristics of Microcystit Flos-Aquae

2021 ◽  
Author(s):  
Yiting Nan ◽  
Peiyong Guo ◽  
Hui Xing ◽  
Sijia Chen ◽  
Bo Hu ◽  
...  
Keyword(s):  
Particle Size ◽  
Particulate Matter ◽  
Protein Content ◽  
Suspended Particulate Matter ◽  
Soluble Protein ◽  
Suspended Particles ◽  
Dose Effect ◽  
Soluble Protein Content ◽  
Sod Activity ◽  
Suspended Particulate

Abstract The effects of different concentrations (100,150,200,250 mg/L) and different particle sizes (0–75µm, 75–120µm, 120–150µm, 150–500µm) on soluble protein content, SOD and CAT activity, MDA content, chlorophyll a content and photosynthetic parameters of Microcystis flos-aquae were studied, the mechanism of the effect of suspended particulate matter on the physiology and biochemistry of Microcystis flos-aquae was discussed. The results showed that the soluble protein content of Microcystis flos-aquae did not change obviously after being stressed by suspended particles of different concentration/diameter. The SOD activity of Microcystis flos-aquae increased at first and then decreased with the increase of the concentration of suspended particulate matter. The SOD activity of Microcystis flos-aquae reached 28.03 U/mL when the concentration of suspended particulate matter was 100 mg/L. The CAT activity of Microcystis flos-aquae increased with the increase of the concentration of suspended particles, and reached the maximum value of 12.45 U/mgprot in the concentration group of 250 mg/L, showing a certain dose-effect. The effect of small particle size on SOD, CAT and MDA of Microcystis flos-aquae was more significant than that of large particle size. The larger the concentration and the smaller the particle size, the stronger the attenuation of light and the lower the content of chlorophyll a. Both Fv/Fm and Fv/F0 of Microcystis flos-aquae increased at first and then decreased under different concentration/size of suspended particles. The relative electron transfer rate gradually returned to the normal level with the passage of time. There was no significant difference in α value between treatment group and control group, ETRmax and Ik decreased.

scholarly journals Mutation in neurospora crassa with leaf extract of citrus aurantifolia and their soluble protein content

1970 ◽  
Vol 19 (2) ◽  
pp. 151-155
Author(s):  
Apurba Lal Ray ◽  
Mahbuba Akhter Jahan ◽  
Tahsina Rahim
Keyword(s):  
Neurospora Crassa ◽  
Protein Content ◽  
Soluble Protein ◽  
Mycelial Growth ◽  
Leaf Extract ◽  
Mutagenic Effect ◽  
Wild Type ◽  
Soluble Protein Content ◽  
Citrus Aurantifolia ◽  
Morphological Mutants

Leaf extract of Citrus aurantifolia exhibited remarkable inhibitor effect on the radial mycelial growth of Neurospora crassa. The extract also showed mutagenic effect and atleast six morphological mutants of the fungus were detected including albino (al 243), vigorous (vg 117), fluffy (fl 220), colonial (cl 232), conidial band (con. band 171) and dirty (dir 83). The mutants were used for estimation of soluble protein in comparison with the wild type (Ema). The soluble protein content increased to some extent in case of the mutants con. band 171 (192.86 μg/ml), cl 232 (188.57 μg/ml) and vg 117 (186.43 μg/ml) as compared to the wild type (182.14 μg/ml). On the other hand, the soluble protein content was remarkably decreased in case of the mutant al 243 (94.28 μg/ml), which was about 50% less than the control. This indicates that the leaf extract not only effect colony morphology but possesses profound effect on growth and metabolism of the fungus. Key words: Neurospora crassa; Mutation; Leaf extract; Soluble protein DOI: http://dx.doi.org/10.3329/dujbs.v19i2.8958 DUJBS 2010; 19(2): 151-155

Impact of Temperatures and pH on Soluble Protein Content and Protein Profile of PY79 (Wild Type) and Sporulation Defective Mutant Strains of Bacillus

2007 ◽  
Vol 2 (11) ◽  
pp. 866-870
Author(s):  
Saira Anwar . ◽  
Anjum Nasim Sabri . ◽  
Hazir Rehman . ◽  
Muhammad Faisal . ◽  
Shahida Hasnain .
Keyword(s):  
Protein Content ◽  
Soluble Protein ◽  
Protein Profile ◽  
Wild Type ◽  
Soluble Protein Content ◽  
Defective Mutant ◽  
Mutant Strains

scholarly journals Mycorrhizal efficacy of trifoliate orange seedlings on alleviating temperature stress

2011 ◽  
Vol 57 (No. 10) ◽  
pp. 459-464 ◽  
Author(s):  
Q.S. Wu
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Protein Content ◽  
Temperature Stress ◽  
Soluble Protein ◽  
Mycorrhizal Colonization ◽  
Poncirus Trifoliata ◽  
Trifoliate Orange ◽  
Soluble Protein Content ◽  
Entry Points

Citrus plants often suffer from temperature stress, which seriously inhibits tree growth and even results in tree death. The present experiment was conducted to evaluate the effects of Glomus mosseae on growth, root morphology, superoxide dismutase (SOD) and catalase (CAT) activities, and soluble protein content of trifoliate orange (Poncirus trifoliata) seedlings at low (15°C), optimum (25°C) and high (35°C) temperatures. Sixty-eight days after temperature stresses, mycorrhizal colonization and number of both entry points and vesicles were significantly inhibited by low or high temperature. Mycorrhizal seedlings recorded significantly higher growth characteristics than non-mycorrhizal seedlings at both optimum and high temperatures, but the beneficial effects were almost lost at low temperature. Generally, mycorrhizal seedlings presented notably higher root traits (projected area, surface area, number of forks and volume) than non-mycorrhizal seedlings regardless of temperature levels. Mycorrhizal colonization significantly increased SOD and CAT activities and soluble protein content at high temperature, increased only SOD activity at optimum temperature, and decreased only soluble protein content at low temperature. It suggests that mycorrhizal alleviation of temperature stress in trifoliate orange seedlings was at high temperature, but the alleviation was obviously weakened at low temperature.

Ozone effects on soluble protein content of Acer negundo, Quercus robur and Platanus spp. pollen

Aerobiologia ◽  
2013 ◽  
Vol 29 (3) ◽  
pp. 443-447 ◽  
Author(s):  
H. Ribeiro ◽  
L. Duque ◽  
R. Sousa ◽  
I. Abreu
Keyword(s):  
Protein Content ◽  
Soluble Protein ◽  
Quercus Robur ◽  
Soluble Protein Content ◽  
Acer Negundo

Effects of auxins on soluble carbohydrates, starch and soluble protein content in Aechmea blanchetiana (Bromeliaceae) cultured in vitro

2010 ◽  
Vol 125 (3) ◽  
pp. 451-455 ◽  
Author(s):  
Edison Paulo Chu ◽  
Armando Reis Tavares ◽  
Shoey Kanashiro ◽  
Patricia Giampaoli ◽  
Erika Szeibel Yokota
Keyword(s):  
Protein Content ◽  
Soluble Protein ◽  
Soluble Carbohydrates ◽  
Soluble Protein Content

Photosynthesis, vegetative habit and culinary properties of sage (Salvia officinalis) in response to low-light conditions

2014 ◽  
Vol 94 (5) ◽  
pp. 881-889 ◽  
Author(s):  
Christine Mapes ◽  
Yan Xu
Keyword(s):  
Protein Content ◽  
Plant Height ◽  
Soluble Protein ◽  
Photochemical Efficiency ◽  
Leaf Size ◽  
Salvia Officinalis ◽  
Light Conditions ◽  
Soluble Protein Content ◽  
Low Light ◽  
Double Blind

Mapes, C. and Xu, Y. 2014. Photosynthesis, vegetative habit and culinary properties of sage (Salvia officinalis) in response to low-light conditions. Can. J. Plant Sci. 94: 881–889. Culinary sage (Salvia officinalis) is known to grow better at sunny locations with good drainage. However, when there is a necessity to propagate it in controlled environments with minimal additional lighting, or at shady locations, how significantly its growth and production would be restricted has not been well investigated. The objective of this study was to examine the responses of sage grown in a greenhouse over the winter when ambient light in the greenhouse is lower than 212 μmol m−2 s−1 (or a daily light integral of 9.2 mol m−2 d−1). Sage seedlings were planted in growing media and covered with various shade cloths to reach 70, 50 and 30% of the ambient irradiance. Photochemical efficiency and in situ chlorophyll status were estimated at 7, 21, and 56 d. The daily leaf emergence rate was calculated by monitoring changes in leaf number. Plant height, leaf size, biomass, aroma rating and soluble protein content of the sage plants grown under various light levels were measured at 84 d. The results indicate that light impacted the integrity of chloroplasts and the photosynthetic capacity of sage plants, as manifested by the lower the light level, the more the declines in variable fluorescence/maximal fluorescence and chlorophyll content index. Biochemical analysis revealed that the concentration of chlorophyll (per gram leaf dry mass) slightly increased under 50 and 30% light, but that of carotenoids was not changed. Light also affected the vegetative habit of sage plants. With reduced light intensity, plant height increased, whereas leaf size and number decreased. Double-blind aroma testing suggested that adequate light intesity might be required for the biosynthesis of essential oil in sage, attenuating its aroma. The soluble protein content in sage leaves declined at 50 and 30% light, suggesting a deminished source of essential amino acids contained in the plant. In summary, sage responds sensitively to reducing irradiance, which directly restricts its photosynthesis, and thus alters its vegetative growth and culinary properties.

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