Peroxidase Activity in <i>Ulva lactuca </i>under Desiccation

Murthy, M. S. R.; Sharma, Chand

doi:10.1515/botm.1989.32.6.511

Cited by 13 publications

(9 citation statements)

References 11 publications

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“…Desiccation enhances the uptake of NO, and N H t in Fucus distichus and has a similar effect on HPOZ-uptake when P limitation is induced by N enrichment (Thomas and Turpin 1980). Photosynthetic rates in air are generally enhanced by moderate desiccation (see Madsen and Maberly 1990), and studies on the activities of a variety of enzymes suggest that emersion produces a general stimulation of several aspects of metabolism (Murthy et al 1986, Murthy and Sharma 1989. The increase in N uptake following emersion may be a mechanism to counteract an N deficit that occurs when metabolically active plants are isolated from their source of nutrients.…”

Section: Limitation Stressmentioning

confidence: 99%

Stress Tolerance in Intertidal Seaweeds

Davison

Pearson

1996

Journal of Phycology

476

347

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Intertidal seaweeds are periodically exposed to air where they experience a variety of potentially stressful environmental conditions, including nutrient limitation, high light, high and low temperature, desiccation, and osmotic stress. This paper considers the current understanding of stress tolerance in intertidal seaweeds and discusses ways in which future research could increase our understanding of the role of environmental factors in the ecology and physiology of these algae. We believe research is required in at least three areas. 1) Laboratory physiological studies have established that correlations exist between stress tolerance and the vertical distribution of species. However, little information is available on the importance of stress in determining community structure in nature. Field experiments are essential to relate the impact of single or multiple stresses on the survival, growth, and reproductive output of macroalgae. In paticular, it is necessary to clarify the role of sublethal stress in determining the outcome of competitive interactions. 2) With the exception of obvious lethal effects or damage associated with extreme environmental conditions, such as unusually hot and dry weather, it is difficult to evaluate the occurrence and severity of stress in natural populations of seaweeds. There is a need to develop molecular and biochemical markers specific for individual stresses or groups of stresses to allow the unambiguous and direct determination of stress in situ. 3) Despite the apparent importance of stress in intertidal seaweeds, we are largely ignorant of the mechanistic basis of tolerance. The application of currently available tools of molecular and cell biology to the investigation of stress‐induced transcriptional and translational changes could enormously increase our understanding of both the sites of, and pathways involved in, stress tolerance. In summary, there are numerous unanswered fundamental questions about the stress tolerance of intertidal seaweeds, providing opportunities for research ranging from field ecology to molecular biology and biochemistry.

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Section: Limitation Stressmentioning

confidence: 99%

Stress Tolerance in Intertidal Seaweeds

Davison

Pearson

1996

Journal of Phycology

476

347

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“…A different response to desiccation is displayed by Ulva lactuca (Chlorophyta) when growing in the upper littoral zone. Here, activities of the enzymes, nitrate reductase, amylase, invertase, and peroxidase, are markedly increased presumably as part of an adaptation mechanism to extended periods of emergence 5–7 . However, thermal stress responses in intertidal seaweeds have received little attention.…”

Section: Introductionmentioning

confidence: 99%

Thermal stress responses of a sterile mutant of Ulva pertusa (Chlorophyta)

Kakinuma¹,

Shibahara²,

Ikeda

et al. 2001

Fisheries Sci

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SUMMARY: The thermal stress responses of a sterile mutant of the marine alga Ulva pertusa were investigated at 20°C and 30°C. The amounts of the photosynthetic pigments, β‐carotene, chlorophylls a and b, lutein, neoxanthin, and violaxanthin, were 1.4–2.4 times higher in the 30°C‐cultivated alga than in the 20°C‐cultivated alga. The free amino acids, asparagine, aspartic acid, glutamine, glutamic acid, glycine, and serine, were abundant in the 20°C‐cultivated alga, and increased 1.9–10.5‐fold in response to thermal stress (30°C). Total carbon and nitrogen contents also increased in the 30°C‐cultivated alga. Sodium dodecylsulfate‐polyacrylamide gel electrophoretic patterns of total proteins extracted from both temperature‐treated algae showed the increases of 20, 25, and 90 kDa proteins in the 30°C‐cultivated alga. Isozyme assays for 20 enzymes showed a different banding pattern only in the case of glutamate dehydrogenase (GDH). Although it was observed that both temperature‐treated algae possessed NAD+‐ and NADP+‐specific GDH, the 30°C‐cultivated alga had an additional NADP+‐specific GDH (NADP‐GDH). These results suggest that NADP‐GDH compensates for the thermally induced decreases in nitrogen assimilation efficiency and thereby regulates nitrogen metabolism under conditions of temperature stress.

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“…Following environmental stress, ROS levels accumulate much more rapidly in nonacclimated (i.e., less‐stress‐tolerant) species (Pastori and Trippi 1993, Collén and Davison 1999a,b) than in conditioned (stress‐tolerant) species (Butow et al 1994, Tottempudi et al 1994). The activities of antioxidant enzymes can be significantly higher in more‐stress‐tolerant organisms (Murthy and Sharma 1989, Dummermuth et al 2003, Choo et al 2004). Thus, enzymatic activity reflecting the status of an organelle’s oxidative machinery may be used as an indicator of cell acclimation and stress (Downs et al 2000, Miller‐Morey and Van Dolah 2004).…”

mentioning

confidence: 99%

INTRASPECIFIC VARIATION IN STRESS‐INDUCED HYDROGEN PEROXIDE SCAVENGING BY THE ULVOID MACROALGA ULVA LACTUCA¹

Ross

Alstyne

2007

Journal of Phycology

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We investigated the presence and kinetics of the oxidative stress response in intertidal and subtidal individuals of the ulvoid macroalga Ulva lactuca L. Stress responses, as measured with both enzymatic and fluorescent-based antioxidant assays, differed between individuals collected from a subtidal and an intertidal habitat. Subtidal individuals secreted significantly more hydrogen peroxide (H 2 O 2 ) than intertidal individuals when subjected to osmotic stress or desiccation. The activity of reactive-oxygenscavenging enzymes and the ability to scavenge exogenous H 2 O 2 were lower in subtidal than in intertidal individuals, suggesting that subtidal individuals are less stress tolerant. In vitro experimentation demonstrated that millimolar concentrations of dimethylsulfoniopropionate (DMSP) and its breakdown products could efficiently scavenge H 2 O 2 , with DMSP being a less-effective scavenger than dimethyl sulfide (DMS), acrylic acid, and acrylate. The addition of H 2 O 2 at concentrations of 2.5 mM or greater induced the cleavage of DMSP into DMS and acrylic acid in subtidal individuals. Intertidal individuals were affected in the same manner with the addition of 5 mM H 2 O 2 . There were no differences in the amounts of DMSP cleavage in subtidal and intertidal algae when the algae were subjected to hyposaline conditions. Our data suggest that the oxidative-stress-induced cleavage of DMSP affords products with efficient H 2 O 2 -scavenging abilities. In addition, U. lactuca individuals growing in intertidal habitats are better acclimatized to changing environments and thus have a higher threshold for oxidative stress than conspecifics in subtidal habitats.

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Peroxidase Activity in Ulva lactuca under Desiccation

Cited by 13 publications

References 11 publications

Stress Tolerance in Intertidal Seaweeds

Stress Tolerance in Intertidal Seaweeds

Thermal stress responses of a sterile mutant of Ulva pertusa (Chlorophyta)

INTRASPECIFIC VARIATION IN STRESS‐INDUCED HYDROGEN PEROXIDE SCAVENGING BY THE ULVOID MACROALGA ULVA LACTUCA¹

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Peroxidase Activity in Ulva lactuca under Desiccation

Cited by 13 publications

References 11 publications

Stress Tolerance in Intertidal Seaweeds

Stress Tolerance in Intertidal Seaweeds

Thermal stress responses of a sterile mutant of Ulva pertusa (Chlorophyta)

INTRASPECIFIC VARIATION IN STRESS‐INDUCED HYDROGEN PEROXIDE SCAVENGING BY THE ULVOID MACROALGA ULVA LACTUCA1

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INTRASPECIFIC VARIATION IN STRESS‐INDUCED HYDROGEN PEROXIDE SCAVENGING BY THE ULVOID MACROALGA ULVA LACTUCA¹