Effects of water regulation on biosynthesis of calycosin-7-O-β-D-glucoside in Astragalus membranaceus var. mongholicus / 中国中药杂志

The effects of water regulation on the biosynthesis of calycosin-7-O-β-D-glucoside in 2-year-old Astragalus membranaceus var. mongholicus were studied,and the mechanism was explained from the aspects of key enzyme gene expression and antioxidant enzyme system. The content of calycosin-7-O-β-D-glucoside was determined by HPLC,and the expression levels of six key enzyme genes( PAL,4 CL,CHS,CHI,IFS,13'H) in the synthesis pathway were analyzed by q RT-PCR. The activities of protective enzymes and contents of osmoregulation substances and malondialdehyde were also determined. In the water deficit group,the maximum concentration of calycosin-7-O-β-D-glucoside was 0. 49 mg·g-1 on the 24 th day of treatment. In the whole water regulation,the water deficit group outweighed the water adequate group in osmoregulation substance and MDA contents. The activities of A. membranaceus var.mongholicus antioxidant enzymes SOD,POD,and CAT increased during the initial period of water regulation,but decreased with time.The expression of PAL,CHS,and 13'H in the water deficit group was at a low level,and the 4 CL had active expression,slightly lower than that in the water adequate group. The expression of CHI and IFS elevated rapidly when water deficit occurred. Correlation analysis showed that the content of calycosin-7-O-β-D-glucoside was positively correlated with CHI expression( P<0. 01) and IFS expression( P<0. 05). Therefore,water regulation can change the accumulation pattern of calycosin-7-O-β-D-glucoside,and water deficit may be an effective way to increase its content. CHI and IFS are the key genes in response to water deficit.

Normatividad del agua en Colombia ¿democratización o privatización? / Water regulations in Colombia democratization or privatization?

El objetivo de este trabajo es hacer una reflexión crítica de la normatividad sobre el agua en Colombia a la luz tanto de las discusiones y directrices internacionales como de las contradicciones entre la democratización y privatización que emergen con los ajustes y cambios relacionados con el agua impuestos en el país, principalmente, desde los años 90. La metodología utilizada fue la revisión bibliográfica y documental. Como resultados de la investigación pudimos entender que existen dos cuerpos normativos para la gestión del agua en Colombia. En primer lugar, las generalidades de lo que concierne a la conservación y uso del agua como recurso natural que se encuentran contempladas en el Código de Recursos Naturales Renovables de 1974, la Ley 99 de 1993 y en la Política Nacional de Gestión Integral del Recurso Hídrico. En segundo lugar, lo atinente al servicio público domiciliario de agua potable que se encuentra regulado por la Ley 142 de 1994. Ello evidencia una fragmentación en la normatividad y lo que se requiere es entender los sistemas hídricos como una unidad dinámica y compleja. Adicionalmente, con esta ley 142 se posibilitó la privatización de parte de las actividades de abastecimiento de agua potable, con lo cual el Estado pasó de ser el prestador del servicio de acueducto a ser su regulador. Como conclusión consideramos necesario introducir un enfoque de equidad en la provisión de agua y el fortalecimiento del sector público descentralizado en el país, que promueva una gestión ambiental coordinada. Por otra parte, se evidencia que la defensa del agua como bien común intenta materializarse en estrategias que se oponen a la privatización y se fundamentan en la noción de que el acceso al líquido vital es un derecho humano y en el presupuesto de que el agua, a diferencia de cualquier commodity, es insustituible.

The objective of this work is to make a critical reflection of the normativity on water in Colombia, in the light of international discussions and guidelines and the contradictions between democratization and privatization that emerge with the adjustments and changes related to water imposed in the country, mainly since the 90s. The methodology used was bibliographic and documentary review. As results and conclusions of the research, it was possible to understand that there are two regulatory bodies for water management in Colombia. In the first place, the generalities concerning the conservation and use of water as a natural resource, which are considered in the Code of Renewable Natural Resources of 1974, Law 99 of 1993 and in the National Policy of Comprehensive Management of Water Resources. In the second place, what concerns the residential water service, which is regulated by Law 142 of 1994. This demonstrates a fragmentation in the normativity and what is required is to understand the water resource as a dynamic and complex unit. Additionally, it was possible to privatize the part of the drinking water supply activities with Law 142, with which the State went from being the provider of the water service to being its regulator. In conclusion, it is considered necessary to introduce an equity approach in the provision of water and the strengthening of the decentralized public sector in the country which promotes coordinated environmental management. On the other hand, it is evident that, the defense of water as a common good, tries to materialize in strategies that oppose privatization and are based on the notion that, access to the vital liquid is a human right, and in the assumption that, water, unlike any commodity, is irreplaceable.

Short-term water changes response of saponin biosynthesis process in Astragalus membranceus / 中国中药杂志

The study is aimed to explore the effect of different water on the content of total saponins,astragaloside Ⅳ and gene expression in the growth of Astragalus membranceus. In this study, one-year-old A. membranaceus was used as the experimental material, by pot culture different water treatments were simulated at herbal garden in Jilin Agricultural University. The content of astragaloside Ⅳ was determined by HPLC and the total saponins by UV spectrophotometry. With 18 S RNA as a reference gene, fluorescent quantitative PCR was applied to analyze the eight key enzymes in astragalus saponin synthesis pathway AACT,HMGS,HMGR,IDI,FPS,SS,SE,CAS expression. With the decrease of soil water, the content of astragaloside Ⅳ in the root tissue of A. membranaceus showed an increasing trend, up to 1.46 mg·g~(-1). The total saponin content tended to increase, up to 6.80 mg·g~(-1). The results of relative expression of genes showed that the eight genes showed different effects at different water. With the change of soil water content, the amount of(AACT,IDI,SS) relative expression in drought stress group firstly increased and then decreased, then increased, and then decreased. The amount of(HMGS,HMGR,FPS) relative expression in drought stress group increased firstly and then decreased. The amount of(SE,CAS) relative expression in drought stress group increased firstly and then decreased, and continued to decrease after rehydration. The expression of key enzyme genes involved in the synthesis of astragaloside was influenced by each other, and the expression of key enzyme in roots showed a correlation with the content of astragaloside. Correlation analysis showed that there was a very significant positive correlation between HMGR gene and total saponins content in drought stress group and a significant negative correlation between content of CAS and total saponins. The contents of FPS,SE,CAS and astragaloside Ⅳ were very significantly and negative correlated. The relationship between other genes and quality was positive. Therefore, HMGR, FPS, SE and CAS genes have significant effects on the regulation of saponin content under water control. On the 15 th day after water regulation, the total amount of astragaloside and total saponins reached the highest value and could be harvested.

Preliminary study on response and its mechanism of ginsenoside biosynthesis in Panax ginseng to water regulation / 中国中药杂志

The study is aimed to explore the effect of soil moisture content on ginsenoside biosynthesis and explain its mechanism from the perspectives of antioxidant enzyme system and gene expression of key enzymes in the pathway of ginsenoside synthesis. In the study,two years old Panax ginseng was used as the experimental material and three moisture gradient,40% of saturated water content( W1),60%( W2),80%( W3) were set up. The content of 11 monomeric saponins were determined by HPLC. With GAPDH as a reference gene,six key enzymes( HMGR,SS,β-AS,CYP716 A47,CYP716 A52 v2,CYP716 A53 v2) in ginseng saponin synthesis pathway expression were analyzed by fluorescent quantitative PCR and the activities of superoxide dismutase( SOD),peroxidase( POD),catalase( CAT) activity and MDA content were also determined. With the increase of soil water,the content of ginseng saponin and biomass showed an increasing trend. PPD( Rb1,Rc,Rb2,Rd,Rh2,Rb3,Rg3),PPT( Rg1,Re,Rf) ginsenoside,Ro and total ginsenoside reached the maximum value on August 30,were 9.92,5.48,0.63 mg·g-1,respectively. During the whole regulation period,the antioxidant activity of W3 was greater than that of W1,and the MDA content was less than that of W1. At W3,expression levels of β-AS,CYP716 A47 and CYP716 A53 v2 showed an increasing trend,while HMGR and SS genes showed relatively stable expression levels under various water conditions. According to the correlation analysis,HMGR and SS genes in the W3 treatment group were significantly positively correlated with PPD,PPT ginsenoside and Ro,CYP716 A52 v2 gene was significantly positively correlated with Ro,and CYP716 A47 gene was significantly positively correlated with PPD ginsenoside. There was a significant positive correlation between β-AS gene and PPD ginsenoside in W1 and W2 treatment. Therefore,W3 is the optimum moisture content,ginseng total saponins and monomer saponin content is the highest,the gene closely correlation with content of saponins and more conducive to the accumulation of ginsenosides.

Recuperación del funcionamiento hidrológico de ecosistemas de páramo en colombia / Rehabilitation of hydrological functioning of páramo ecosystems in colombia

Los páramos son ecosistemas que se caracterizan por una alta humedad relativa, alta frecuencia de niebla y por tener una vegetación arbustiva y herbácea, adaptada a las condiciones de alta montaña. En condiciones naturales estos ecosistemas presentan una oferta hídrica alta, entre otros servicios ecosistémicos; sin embargo, esto cambia cuando son degradados. A pesar de su importancia son ecosistemas que han sido modificados por el hombre, la mayoría aún sin haber sido estudiados. Este documento presenta los resultados de una investigación realizada en tres páramos en Colombia, en la cual, se evalúa su funcionamiento hidrológico y la capacidad de recuperación, una vez han sido alterados; para esto, se estudió el clima, la hidrología y los suelos. Los resultados indican que estos ecosistemas tienen condiciones climáticas desiguales, que determinan su rendimiento y regulación hídrica; con diferencias en las propiedades hidrofísicas del suelo y contenido de materia orgánica, lo que determina diferencias en su capacidad para retener la humedad y la disponibilidad de agua para las plantas. Estos resultados indican que los páramos, con un grado bajo de disturbio, presentan un alto rendimiento y buena regulación hídrica; pero igual que los páramos intervenidos, recuperan el estado natural de las propiedades del suelo y, consecuentemente, su funcionamiento hidrológico, aún en pocas décadas.

Páramos are equatorial alpine ecosystems characterized by a high air humidity, frequency of fog and the presence of shrub and herbaceous vegetation adapted to the specific equatorial alpine conditions. Under natural conditions these ecosystems present a high water yield, among other ecosystem services, however, this changes when they are degraded. Despite their importance, they are ecosystems that have been modified by man, most of them even without having been studied. This paper presents the results of a hydrological research carried out in three páramos in Colombia, which evaluates their hydrological functioning and their capacity for recovery once they are altered. Therefore, we studied their climate, hydrology, and soils properties. Results indicate that these ecosystems have different climatic conditions, which determine their water yield and water regulation. Differences in the hydro-physical properties of soils and organic matter content, which determine differences in their capacity to retain water and on the magnitude of the water available for plants. These results indicate that undisturbed páramos or with a low degree of disturbance present high water yield and good water regulation; and intervened páramos can recover the natural conditions of soil properties, and consequently their hydrological functioning, even in a few decades.