The apoplast is an interconnected compartment with a thin water-film that alkalinizes under stress. This systemic pH increase may be a secondary effect without functional implications, arising from ion movements or pr...The apoplast is an interconnected compartment with a thin water-film that alkalinizes under stress. This systemic pH increase may be a secondary effect without functional implications, arising from ion movements or proton-pump regulations. On the other hand, there are increasing indications that it is part of a mechanism to withstand stress. Regardless of this controversy, alkalinization of the apoplast has received little attention. The apoplastic pH （PHapo） increases not only during plant-pathogen interactions but also in response to salinity or drought. Not much is known about the mechanisms that cause the leaf apoplast to alkalinize, nor whether, and if so, how functional impact is conveyed. Controversial explanations have been given, and the unusual complexity of pHapo regulation is considered as the primary reason behind this lack of knowledge. A gathering of scattered information revealed that changes in PHapo convey functionality by regulating stomatal aperture via the effects exerted on abscisic acid. Moreover, apoplastic alkalinization may regulate growth under stress, whereas this needs to be verified. In this review, a comprehensive survey about several physiological mechanisms that alkalize the apoplast under stress is given, and the suitability of apoplastic alkalinization as transducing element for the transmission of sensory information is discussed.展开更多
High-alkali treatment using sodium hydroxide(NaOH)injection can be a therapeutic approach for killing tumor cells.Alkalization can damage cellular structures and lead to cell death.Increased alkalinity can also enhanc...High-alkali treatment using sodium hydroxide(NaOH)injection can be a therapeutic approach for killing tumor cells.Alkalization can damage cellular structures and lead to cell death.Increased alkalinity can also enhance the efficacy of certain chemotherapeutic drugs such as doxorubicin(DOX).In this study,NaOH-loaded starch implants(NST implants)were used to induce hyperalkalization(increase pH)in the tumor environment,thereby inducing necrosis and enhancing the effects of DOX.NaOH is a strongly alkaline substance that can increase the pH when injected into a tumor.However,the administration of NaOH can have toxic side effects because it increases the pH of the entire body,not just at the tumor site.To overcome this problem,we developed an injectable NST implant,in which NaOH can be delivered directly into the tumor.This study showed that NST implants could be easily administered intratumorally in mice bearing 4T1 tumors and that most of the NaOH released from the NST implants was delivered to the tumors.Although some NaOH from NST implants can be systemically absorbed,it is neutralized by the body’s buffering effect,thereby reducing the risk of toxicity.This study also confirmed both in vitro and in vivo that DOX is more effective at killing 4T1 cells when alkalized.It has been shown that administration of DOX after injection of an NST implant can kill most tumors.Systemic absorption and side effects can be reduced using an NST implant to deliver NaOH to the tumor.In addition,alkalinization induced by NST implants not only exerts anticancer effects but can also enhance the effect of DOX in killing cancer cells.Therefore,the combination of NaOH-loaded starch implants and DOX treatment has the potential to be a novel therapy for tumors.展开更多
Pollen tube growth is essential for successful double fertilization, which is critical for grain yield in crop plants. Rapid alkalinization factors(RALFs) function as ligands for signal transduction during fertilizati...Pollen tube growth is essential for successful double fertilization, which is critical for grain yield in crop plants. Rapid alkalinization factors(RALFs) function as ligands for signal transduction during fertilization. However, functional studies on RALF in monocot plants are lacking.Herein, we functionally characterized two pollen-specific RALFs in rice(Oryza sativa) using multiple clustered regularly interspaced palindromic repeats(CRISPR)/CRISPR-associated protein 9-induced loss-of-function mutants,peptide treatment, expression analyses, and tag reporter lines. Among the 41 RALF members in rice, OsRALF17 was specifically expressed at the highest level in pollen and pollen tubes.Exogenously applied OsRALF17 or OsRALF19peptide inhibited pollen tube germination and elongation at high concentrations but enhanced tube elongation at low concentrations, indicating growth regulation. Double mutants of OsRALF17 and OsRALF19(ralf17/19) exhibited almost full male sterility with defects in pollen hydration, germination, and tube elongation,which was partially recovered by exogenous treatment with OsRALF17 peptide. This study revealed that two partially functionally redundant OsRALF17 and OsRALF19 bind to Oryza sativa male-gene transfer defective 2(OsMTD2) and transmit reactive oxygen species signals for pollen tube germination and integrity maintenance in rice. Transcriptomic analysis confirmed their common downstream genes, in osmtd2 and ralf17/19. This study provides new insights into the role of RALF, expanding our knowledge of the biological role of RALF in regulating rice fertilization.展开更多
Faced with the scarcity of surface water accentuated by climate change, particularly in many arid and semi-arid countries, the quality of groundwater used for irrigation is a concern to agronomists and hydrogeologists...Faced with the scarcity of surface water accentuated by climate change, particularly in many arid and semi-arid countries, the quality of groundwater used for irrigation is a concern to agronomists and hydrogeologists. When </span><span style="font-family:Verdana;">these waters are of deep origin, they may have high mineralization and</span><span style="font-family:Verdana;"> chemical compositions unsuitable for irrigation;in particular, they may alter soils and crops. It is therefore important to optimize the spatial estimation of the salinity of these waters and contribute to better knowledge of their quality, through an adapted and robust statistical and geostatistical approach. In the case of north-eastern Algeria, the objective of this study is to characterize the quality of deep waters and to test two interpolation methods (Inverse distance weight and ordinary Kriging) of their electrical conductivity (EC) as an indicator of their salinity and of the risk of damaging irrigated soils. 51 ground</span><span style="font-family:Verdana;">water samples were taken in this region where there are many thermal </span><span style="font-family:Verdana;">springs, the water of which is used for irrigation and often is highly mineralized (EC between 0.6 and 26.6 dS/m). The geology is composed of karstic rocks crossed by large faults that allow deep water to rise. Based on major elements contents, analysis of the hydrochemical facies of these waters shows that the main facies are hyperchlorinated sodium (38%) and sulfated calcium (32%). The RSC (Residual Sodium Carbonate) and SAR (Irrigation water salt) indexes were used to assess the water quality. The results indicate that the majority of the sampled</span><span style="color:red;"> </span><span style="font-family:Verdana;">groundwater present a risk for soils irrigated with these waters (almost 1/3 presents a strong risk). The risk for the soils seems to be explained by the positive value of the residual alkalinity, and the high risks of sodization and alkalinization. T展开更多
The sand fly Lutzomyia longipalpis is the main vector of Leishmania infantum in the Americas.Female sand flies ingest sugar-rich solutions and blood,which are digested in the midgut.Digestion of nutrients is an essent...The sand fly Lutzomyia longipalpis is the main vector of Leishmania infantum in the Americas.Female sand flies ingest sugar-rich solutions and blood,which are digested in the midgut.Digestion of nutrients is an essential function performed by digestive enzymes,which require appropriate physiological conditions.One of the main aspects that influence enzymatic activity is the gut pH,which must be tightly controlled.Considering second messengers are frequently involved in the coordination of tightly regulated physiological events,we investigated if the second messenger cAMP would participate in the process of alkalinization in the abdominal midgut of female L.longipalpis.In midguts containing the indicator dye bromothymol-blue,cAMP stimulated the alkalinization of the midgut lumen.Through another technique based on the use of fluorescein as a pH indicator,we propose that cAMP is involved in the alkalinization of the midgut by activating HCO3-transport from the enterocyte's cytoplasm to the lumen.The results strongly suggested that the carrier responsible for this process would be a HCO3−/Cl−antiporter located in the enterocytes’apical membrane.Hematophagy promotes the release of alkalinizing hormones in the hemolymph;however,when the enzyme adenylyl cyclase,responsible for cAMP production,was inhibited,we observed that the hemolymph from blood-fed L.longipalpis’females did not stimulate midgut alkalinization.This result indicated that hormone-stimulated alkalinization is mediated by cAMP.In the present study,we provide evidences that cAMP has a key role in the control of intestinal pH.展开更多
The present investigation involves the separation of zinc and nickel from a sulfate solution using the acidic leaching of zinc plant residue after cadmium removal step as precursor(42.88 wt%Zn,8.50 wt%Cd and 2.33 wt%N...The present investigation involves the separation of zinc and nickel from a sulfate solution using the acidic leaching of zinc plant residue after cadmium removal step as precursor(42.88 wt%Zn,8.50 wt%Cd and 2.33 wt%Ni).Separation of nickel from the solution was done by pouring it into a strong alkaline sodium hydroxide solution due to precipitation of nickel hydroxide and conversion of zinc to the soluble Zn(OH)_(4)^(2-)complex.Higher degrees of separation were reached by pouring more diluted solutions into the stronger alkaline media.To clear pursue of the process,design of experimental methodology was applied for experiments.Scrutinizing different washing steps on nickel-rich precipitates shows that the washing process decreases zinc content and thereby increases overall selectivity coefficient.Outcomes show that,at the optimized condition,Ni/Zn weight ratio in the solid product becomes about 104 times higher than the initial ratio in the initial feed solution and a nickel concentrate with 29.98 wt%Ni and 5.99 wt%Zn is achieved.At the same time,the chemical analysis of filtrate shows only 4.4 mg·L^(-1)Ni in the alkaline zinc solution,which means that over 99%nickel is recovered.The study on changes of zinc concentration with time shows that the process could be completed only after few minutes.展开更多
文摘The apoplast is an interconnected compartment with a thin water-film that alkalinizes under stress. This systemic pH increase may be a secondary effect without functional implications, arising from ion movements or proton-pump regulations. On the other hand, there are increasing indications that it is part of a mechanism to withstand stress. Regardless of this controversy, alkalinization of the apoplast has received little attention. The apoplastic pH （PHapo） increases not only during plant-pathogen interactions but also in response to salinity or drought. Not much is known about the mechanisms that cause the leaf apoplast to alkalinize, nor whether, and if so, how functional impact is conveyed. Controversial explanations have been given, and the unusual complexity of pHapo regulation is considered as the primary reason behind this lack of knowledge. A gathering of scattered information revealed that changes in PHapo convey functionality by regulating stomatal aperture via the effects exerted on abscisic acid. Moreover, apoplastic alkalinization may regulate growth under stress, whereas this needs to be verified. In this review, a comprehensive survey about several physiological mechanisms that alkalize the apoplast under stress is given, and the suitability of apoplastic alkalinization as transducing element for the transmission of sensory information is discussed.
基金supported by Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(2021R1F1A1047799)supported by the Dongguk University Research Fund of 2021
文摘High-alkali treatment using sodium hydroxide(NaOH)injection can be a therapeutic approach for killing tumor cells.Alkalization can damage cellular structures and lead to cell death.Increased alkalinity can also enhance the efficacy of certain chemotherapeutic drugs such as doxorubicin(DOX).In this study,NaOH-loaded starch implants(NST implants)were used to induce hyperalkalization(increase pH)in the tumor environment,thereby inducing necrosis and enhancing the effects of DOX.NaOH is a strongly alkaline substance that can increase the pH when injected into a tumor.However,the administration of NaOH can have toxic side effects because it increases the pH of the entire body,not just at the tumor site.To overcome this problem,we developed an injectable NST implant,in which NaOH can be delivered directly into the tumor.This study showed that NST implants could be easily administered intratumorally in mice bearing 4T1 tumors and that most of the NaOH released from the NST implants was delivered to the tumors.Although some NaOH from NST implants can be systemically absorbed,it is neutralized by the body’s buffering effect,thereby reducing the risk of toxicity.This study also confirmed both in vitro and in vivo that DOX is more effective at killing 4T1 cells when alkalized.It has been shown that administration of DOX after injection of an NST implant can kill most tumors.Systemic absorption and side effects can be reduced using an NST implant to deliver NaOH to the tumor.In addition,alkalinization induced by NST implants not only exerts anticancer effects but can also enhance the effect of DOX in killing cancer cells.Therefore,the combination of NaOH-loaded starch implants and DOX treatment has the potential to be a novel therapy for tumors.
基金supported by grants from the National Research Foundation, Ministry of Education, Science and Technology (2019R1C1C1002636 and RS-2023-00217064 to Y.-J.K., 2021R1A4A2001968 to S.T.K., and 2021M3E5E6025387 and 2021R1A5A1032428 to K.-H.J.)the New Breeding Technologies Development Program (PJ01661002 to K.-H.J.)the Rural Development Administration, Republic of Korea。
文摘Pollen tube growth is essential for successful double fertilization, which is critical for grain yield in crop plants. Rapid alkalinization factors(RALFs) function as ligands for signal transduction during fertilization. However, functional studies on RALF in monocot plants are lacking.Herein, we functionally characterized two pollen-specific RALFs in rice(Oryza sativa) using multiple clustered regularly interspaced palindromic repeats(CRISPR)/CRISPR-associated protein 9-induced loss-of-function mutants,peptide treatment, expression analyses, and tag reporter lines. Among the 41 RALF members in rice, OsRALF17 was specifically expressed at the highest level in pollen and pollen tubes.Exogenously applied OsRALF17 or OsRALF19peptide inhibited pollen tube germination and elongation at high concentrations but enhanced tube elongation at low concentrations, indicating growth regulation. Double mutants of OsRALF17 and OsRALF19(ralf17/19) exhibited almost full male sterility with defects in pollen hydration, germination, and tube elongation,which was partially recovered by exogenous treatment with OsRALF17 peptide. This study revealed that two partially functionally redundant OsRALF17 and OsRALF19 bind to Oryza sativa male-gene transfer defective 2(OsMTD2) and transmit reactive oxygen species signals for pollen tube germination and integrity maintenance in rice. Transcriptomic analysis confirmed their common downstream genes, in osmtd2 and ralf17/19. This study provides new insights into the role of RALF, expanding our knowledge of the biological role of RALF in regulating rice fertilization.
文摘Faced with the scarcity of surface water accentuated by climate change, particularly in many arid and semi-arid countries, the quality of groundwater used for irrigation is a concern to agronomists and hydrogeologists. When </span><span style="font-family:Verdana;">these waters are of deep origin, they may have high mineralization and</span><span style="font-family:Verdana;"> chemical compositions unsuitable for irrigation;in particular, they may alter soils and crops. It is therefore important to optimize the spatial estimation of the salinity of these waters and contribute to better knowledge of their quality, through an adapted and robust statistical and geostatistical approach. In the case of north-eastern Algeria, the objective of this study is to characterize the quality of deep waters and to test two interpolation methods (Inverse distance weight and ordinary Kriging) of their electrical conductivity (EC) as an indicator of their salinity and of the risk of damaging irrigated soils. 51 ground</span><span style="font-family:Verdana;">water samples were taken in this region where there are many thermal </span><span style="font-family:Verdana;">springs, the water of which is used for irrigation and often is highly mineralized (EC between 0.6 and 26.6 dS/m). The geology is composed of karstic rocks crossed by large faults that allow deep water to rise. Based on major elements contents, analysis of the hydrochemical facies of these waters shows that the main facies are hyperchlorinated sodium (38%) and sulfated calcium (32%). The RSC (Residual Sodium Carbonate) and SAR (Irrigation water salt) indexes were used to assess the water quality. The results indicate that the majority of the sampled</span><span style="color:red;"> </span><span style="font-family:Verdana;">groundwater present a risk for soils irrigated with these waters (almost 1/3 presents a strong risk). The risk for the soils seems to be explained by the positive value of the residual alkalinity, and the high risks of sodization and alkalinization. T
基金This work was supported by Fundacao de Amparo a Pesquisa do Estado de Minas Gerais(FAPEMIG),Conselho Nacional de Desenvolvimento Cientifico e Teenologico(CNPq),Instituto Nacional de Ciencia e Teenologia-Entomologia Molecular(INCT-EM),and Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior(CAPES).
文摘The sand fly Lutzomyia longipalpis is the main vector of Leishmania infantum in the Americas.Female sand flies ingest sugar-rich solutions and blood,which are digested in the midgut.Digestion of nutrients is an essential function performed by digestive enzymes,which require appropriate physiological conditions.One of the main aspects that influence enzymatic activity is the gut pH,which must be tightly controlled.Considering second messengers are frequently involved in the coordination of tightly regulated physiological events,we investigated if the second messenger cAMP would participate in the process of alkalinization in the abdominal midgut of female L.longipalpis.In midguts containing the indicator dye bromothymol-blue,cAMP stimulated the alkalinization of the midgut lumen.Through another technique based on the use of fluorescein as a pH indicator,we propose that cAMP is involved in the alkalinization of the midgut by activating HCO3-transport from the enterocyte's cytoplasm to the lumen.The results strongly suggested that the carrier responsible for this process would be a HCO3−/Cl−antiporter located in the enterocytes’apical membrane.Hematophagy promotes the release of alkalinizing hormones in the hemolymph;however,when the enzyme adenylyl cyclase,responsible for cAMP production,was inhibited,we observed that the hemolymph from blood-fed L.longipalpis’females did not stimulate midgut alkalinization.This result indicated that hormone-stimulated alkalinization is mediated by cAMP.In the present study,we provide evidences that cAMP has a key role in the control of intestinal pH.
基金the Program from Sahand University of Technology, Tabriz, Iran (No. 13940501)。
文摘The present investigation involves the separation of zinc and nickel from a sulfate solution using the acidic leaching of zinc plant residue after cadmium removal step as precursor(42.88 wt%Zn,8.50 wt%Cd and 2.33 wt%Ni).Separation of nickel from the solution was done by pouring it into a strong alkaline sodium hydroxide solution due to precipitation of nickel hydroxide and conversion of zinc to the soluble Zn(OH)_(4)^(2-)complex.Higher degrees of separation were reached by pouring more diluted solutions into the stronger alkaline media.To clear pursue of the process,design of experimental methodology was applied for experiments.Scrutinizing different washing steps on nickel-rich precipitates shows that the washing process decreases zinc content and thereby increases overall selectivity coefficient.Outcomes show that,at the optimized condition,Ni/Zn weight ratio in the solid product becomes about 104 times higher than the initial ratio in the initial feed solution and a nickel concentrate with 29.98 wt%Ni and 5.99 wt%Zn is achieved.At the same time,the chemical analysis of filtrate shows only 4.4 mg·L^(-1)Ni in the alkaline zinc solution,which means that over 99%nickel is recovered.The study on changes of zinc concentration with time shows that the process could be completed only after few minutes.
