scholarly journals Changes in Agronomic and Physiological Traits of Sugarcane Grown with Saline Irrigation Water

Agronomy ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 722
Author(s):  
Kenta Watanabe ◽  
Hiroo Takaragawa ◽  
Masami Ueno ◽  
Yoshinobu Kawamitsu
Keyword(s):  
Salt Concentration ◽  
Irrigation Water ◽  
Stomatal Closure ◽  
Co2 Assimilation ◽  
Physiological Traits ◽  
Sugar Concentration ◽  
Saline Irrigation ◽  
Saccharum Spp ◽  
The Relationship ◽  
Harmful Effects

In Japan, the highest salt concentration in irrigation water for sugarcane cultivation has been reported to be above 2500 mg L−1, which may cause harmful effects to the crops; however, little information is available on the relationship between the salinity of irrigation water and sugarcane. To investigate its effects on agronomic and physiological traits, a Japanese cultivar, Saccharum spp cv. NiF8, was grown with 0, 200, 500, 1000, 2000, and 3000 mg NaCl L−1 under pot conditions. The treatments significantly lowered leaf area; however, NaCl levels up to 500 mg L−1 did not greatly reduce culm weight and juice sugar concentration. These traits were impaired when the tested cultivar was grown with 1000 mg NaCl L−1 or higher, indicating that salt concentration is desired to be lower than 1000 mg L−1. CO2 assimilation rate was inhibited mainly due to stomatal closure caused by salt stress. The treatments significantly altered Na+, Cl−, and K+ concentrations in juice but not those in leaf, suggesting that juice analysis is an effective method to estimate its salinization status. Culm weight and juice sugar concentration were severely affected as juice conductivity exceeded 900 mS m−1; thereby, sugarcane plants of NiF8 possessing conductivity above this level could be considered salt-stressed where water salinity is a concern.

Modelling Stomatal Responses to Environment in Macadamia integrifolia

1991 ◽  
Vol 18 (6) ◽  
pp. 649 ◽  
Author(s):  
J Lloyd
Keyword(s):  
Stomatal Closure ◽  
Co2 Assimilation ◽  
Leaf Temperature ◽  
Least Squares Regression ◽  
Gain Ratio ◽  
Humidity Response ◽  
Macadamia Integrifolia ◽  
Stomatal Responses ◽  
Simple Equations ◽  
The Relationship

Gas exchange measurements were made of photosynthetic and stomatal responses of Macadamia integrifolia under controlled conditions. Test leaves were subjected to a range of temperatures, humidities and photon irradiances. When stomatal responses to humidity were plotted as a function of vapour mol fraction difference (D) a similar curvilinear response was observed at all temperatures and at photon irradiances of 200 and 1500 μmol quanta m-2 s-1. By contrast, when expressed as a function of relative humidity, different slopes in the humidity response were observed, and at high photon irradiances, stomatal conductances (gs) appeared to have an optimum temperature below 15�C. Simple equations to quantify responses to leaf temperature (TI) and D were developed, the best of which was gs = [1-k1(1-[Tl/Topt)]/k2√D, where Topt is the leaf temperature at which maximal stomatal opening is observed and k1 and k2 are constants fitted by non-linear least squares regression analysis. Calculation of the gain ratio of CO2 assimilation (A) to transpiration (E) (δA/δE) was complicated by effects of D on the relationship between A and leaf intercellular mol fraction of CO2 (CI). Calculation of δA/δE using A/CI relationships derived by varying external CO2 mol fraction at constant D showed the gain ratio to be virtually constant (1.5 mmol mol-1) across a range of leaf temperatures and vapour mol fraction differences but, when calculated directly from the relationship between A and gs, a decrease in δA/δE with D was observed. Macadamia leaves have heavily sclerified bundle sheath extensions and it is considered that this dependence was an artefact due to non-uniform stomatal closure in response to increasing D. It is shown that, at any given temperature, a stomatal response of the form gsD-1/2 gives rise to an approximately constant δA/δE.

scholarly journals Manganese toxicity disrupts indole acetic acid homeostasis and suppresses the CO2 assimilation reaction in rice leaves

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Daisuke Takagi ◽  
Keiki Ishiyama ◽  
Mao Suganami ◽  
Tomokazu Ushijima ◽  
Takeshi Fujii ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Indole Acetic Acid ◽  
Molecular Mechanisms ◽  
Stomatal Closure ◽  
Co2 Assimilation ◽  
Terrestrial Plants ◽  
Mn Toxicity ◽  
Growth Defects ◽  
The Relationship ◽  
Excessive Accumulation

AbstractDespite the essentiality of Mn in terrestrial plants, its excessive accumulation in plant tissues can cause growth defects, known as Mn toxicity. Mn toxicity can be classified into apoplastic and symplastic types depending on its onset. Symplastic Mn toxicity is hypothesised to be more critical for growth defects. However, details of the relationship between growth defects and symplastic Mn toxicity remain elusive. In this study, we aimed to elucidate the molecular mechanisms underlying symplastic Mn toxicity in rice plants. We found that under excess Mn conditions, CO2 assimilation was inhibited by stomatal closure, and both carbon anabolic and catabolic activities were decreased. In addition to stomatal dysfunction, stomatal and leaf anatomical development were also altered by excess Mn accumulation. Furthermore, indole acetic acid (IAA) concentration was decreased, and auxin-responsive gene expression analyses showed IAA-deficient symptoms in leaves due to excess Mn accumulation. These results suggest that excessive Mn accumulation causes IAA deficiency, and low IAA concentrations suppress plant growth by suppressing stomatal opening and leaf anatomical development for efficient CO2 assimilation in leaves.

scholarly journals Manganese toxicity disrupts indole acetic acid homeostasis and suppresses CO2 assimilation reaction in rice plants

2021 ◽  
Author(s):  
Daisuke Takagi ◽  
Keiki Ishiyama ◽  
Mao Suganami ◽  
Tomokazu Ushijima ◽  
Takeshi Fujii ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Indole Acetic Acid ◽  
Molecular Mechanisms ◽  
Stomatal Closure ◽  
Co2 Assimilation ◽  
Terrestrial Plants ◽  
Mn Toxicity ◽  
Rice Plants ◽  
Growth Defects ◽  
The Relationship

Despite the essentiality of Mn in terrestrial plants, its excessive accumulation in plant tissues causes growth defects, known as Mn toxicity. Mn toxicity can be divided into apoplastic and symplastic types depending on its onset. For growth defects, symplastic rather than apoplastic Mn toxicity is hypothesised to be more critical. However, details of the relationship between growth defects and symplastic Mn toxicity remains elusive. In this study, we aimed to elucidate the molecular mechanisms of symplastic Mn toxicity in rice plants. We found that under excess Mn conditions, CO2 assimilation was inhibited by stomatal closure, and both carbon anabolic and catabolic activities were decreased. In addition to stomatal dysfunction, stomatal and leaf anatomical development were also altered by excess Mn accumulation. Furthermore, the indole acetic acid (IAA) concentration was decreased, and auxin-responsive gene expression analyses showed IAA-deficient symptoms in leaves due to excess Mn accumulation. These results suggest that excessive Mn accumulation causes IAA deficiency, and low IAA concentrations suppress plant growth by suppressing stomatal opening and leaf anatomical development for efficient CO2 assimilation in leaves.

The Relationship between Priority and Value of Irrigation Water Used with Prior Appropriation Water Rights

2020 ◽  
Vol 96 (3) ◽  
pp. 384-398 ◽  
Author(s):  
Gi-Eu Lee ◽  
Kimberly Rollins ◽  
Loretta Singletary
Keyword(s):  
Irrigation Water ◽  
Water Rights ◽  
Value Of Irrigation Water ◽  
The Relationship

Novas Considerações sobre a Fotoproteção no Brasil: Revisão de Literatura/New Considerations on the Photoprotection in Brazil: Literature Review

1970 ◽  
Vol 5 (3) ◽  
pp. 80-96
Author(s):  
Mayara Motta Melo ◽  
Clarissa Santos de Carvalho Ribeiro
Keyword(s):  
Skin Cancer ◽  
Solar Radiation ◽  
Literature Review ◽  
Sun Exposure ◽  
International Consensus ◽  
De Se ◽  
Literature Reviews ◽  
Relationship Of ◽  
The Relationship ◽  
Harmful Effects

RESUMOA incidência do câncer de pele vem aumentando a cada ano. Sabe-se que entre outros fatores, a radiação solar é a principal responsável pelo desenvolvimento dessa patologia. A prevenção, feita através da fotoproteção, teria grande impacto nesse cenário. No entanto, as orientações sobre como se proteger dos malefícios do sol devem ser coerentes com a incidência solar da região, os hábitos da população e o fototipo da pele. Os conceitos sobre fotoproteção foram definidos por entidades européias e norte americanas e não devem ser reproduzidos para o Brasil de forma aleatória, pois a incidência solar no Brasil é muito maior, a população tem fototipos diferentes e o hábito de se expor ao sol é muito mais frequente. Portanto, faz-se necessário elaborar conceitos próprios para o Brasil e conscientizar a população sobre os perigos da radiação solar para que a incidência do câncer de pele reduza definitivamente. Essa revisão visa mostrar a relação da radiação solar no Brasil com a pele dos brasileiros e evidenciar a importância da fotoproteção para essa população. Para isso foi feito um levantamento de artigos originais, revisões de literatura, consensos brasileiros e internacionais e livros de dermatologia.Palavras-chave: Fotoproteção, Câncer de pele, Exposição solar, Radiação ultravioleta, Vitamina D. ABSTRACTThe incidence of skin cancer is increasing every year. It is known that among other factors, solar radiation is the main responsible for the development of this pathology. Prevention, made by photoprotection, would have great impact in this scenario. However, the guidelines on how to protect themselves from the sun's harmful effects should be consistent with the sunlight of the region, the habits of the population and the phototype skin. The concepts of photoprotection were defined by European and North American entities and should not be played for Brazil at random, as the solar incidence in Brazil is much higher, people have different skin types and the habit of sun exposure is much more frequent. Therefore, it is necessary to draw up own concepts for Brazil and raise awareness about the dangers of solar radiation, so that the incidence of skin cancer can be definitely reduced. This review aims to show the relationship of solar radiation in Brazil with the skin of Brazilian and to highlight the importance of sun protection for this population. With this purpose, it was  made a survey of original articles, literature reviews , Brazilian and international consensus and dermatology books.Keywords: Photoprotection, Skin cancer, Sun exposure, Ultraviolet radiation, D vitamin.

Experimental Hypercholesterolemia and Auditory Function in the Chinchilla

1982 ◽  
Vol 90 (6) ◽  
pp. 814-818 ◽  
Author(s):  
Tetsuo Morizono ◽  
Michael A. Sikora
Keyword(s):  
Differential Susceptibility ◽  
Control Group ◽  
High Cholesterol Diet ◽  
Auditory Function ◽  
Cholesterol Levels ◽  
Auditory Dysfunction ◽  
Experimental Hypercholesterolemia ◽  
Susceptibility To Noise ◽  
The Relationship ◽  
Harmful Effects

Possible harmful effects of a high-cholesterol diet on auditory function were suggested by our previous work in rabbits, in which evoked potentials were measured from a chronic electrode inserted into the inferior colliculus. However, serum cholesterol levels in those rabbits tended to be extraordinarily high, ie, more than 1,500 mg/dL. Chinchillas were used in the present work as an animal model to study the relationship between hypercholesterolemia and auditory dysfunction. One percent cholesterol in standard Chinchow was fed to chinchillas for three months. The experimental groups showed a high mean cholesterol level of 437 ± 394 mg/dL (N = 9). Isopotential curve of the cochlear microphonics, threshold of action potentials (AP), and endocochlear DC potential did not differ from those in the control group. When moderately intense sound (12 kHz, 95 dB SPL) was given for ten minutes, however, the reduction in AP threshold was significantly greater (P=.036) in the cholesterol group. It is postulated that hypercholesterolemia may be one of the factors involved in differential susceptibility to noise.

When history perpetuates stereotypes and narratives: The burden of historical representations on well-being

2021 ◽  
Author(s):  
Raymond Boateng
Keyword(s):  
Social Identity ◽  
Well Being ◽  
Self Esteem ◽  
Social Identification ◽  
Potential Impact ◽  
Historical Representations ◽  
The Relationship ◽  
Harmful Effects

Previous research outlined that historical representations of different groups underlie stereotypes and prejudice. Considering the gap in the literature on historical representations and their potential impact on the well-being of Africans, we hypothesised that historical representations of Africans and perceptions of these representations among Africans (N = 225 in Europe relate to well-being outcomes in that population. Furthermore, we predicted that the relationship between historical representations and well-being is mediated by stereotype confirmation concerns and social identification. Consistent with our predictions, historical representations were associated with poorer well-being. Particularly, historical representations were related to increased anxiety and low self-esteem through their relationship with stereotype confirmation concerns. Social identity mitigated the harmful effects of historical representations on self-esteem. However, social identity did not mediate the association between historical representations and anxiety. Our findings highlight the effects of historical representations on well-being.

scholarly journals Pickle and Chutney Development from Fresh Hog Plum (Spondias dulcis)

2013 ◽  
Vol 5 (2) ◽  
pp. 67-72
Author(s):  
MHR Bhuiyan
Keyword(s):  
Chemical Composition ◽  
Vitamin C ◽  
Moisture Content ◽  
Salt Concentration ◽  
Storage Stability ◽  
Sugar Concentration ◽  
Initial Concentration ◽  
Overall Acceptability ◽  
Similar Product ◽  
Hog Plum

The experiment was conducted to develop pickle and chutney from fresh hog plum fruit. The pickle was made with 5%, 10%, 15% and 20% salt concentration. The chutneys were made with 25%, 30%, 35% and 40% sugar concentration. Among them, the best pickle and chutney was identified on the basis of overall acceptability. The study showed that the color, flavor, texture and overall acceptability of different pickles and the chutneys were different. The pickle (P15) made with 15% salt and the chutney (C40) made with 40% sugar concentration was best among others of the similar product. Higher concentration of sugar and salt gives higher acceptability for chutney and pickle, respectively. Among different changes in chemical composition, moisture and vitamin C concentration were prominent during preparation of pickle and chutney. The moisture content was 59.69% and 43.08% for pickle and chutney respectively which were nearly two third to half of the initial concentration of fresh hog plum fruit. The storage stability was studied for both the products and it is seen that chutney (4 month) was lower than storage stability of pickle (5 month).DOI: http://dx.doi.org/10.3329/jesnr.v5i2.14604 J. Environ. Sci. & Natural Resources, 5(2): 67-72 2012

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