In the present work on population status,threats and conservation of the spotted pond turtle;Geoclemys hamiltonii(Gray,1830)(Geoemydidae)was conducted in Thatta,Sujawal and Badin districts of Sindh province of Pakista...In the present work on population status,threats and conservation of the spotted pond turtle;Geoclemys hamiltonii(Gray,1830)(Geoemydidae)was conducted in Thatta,Sujawal and Badin districts of Sindh province of Pakistan.A total number of 277 live specimens of G.hamiltonii from southeast province(Sindh)of Pakistan have been collected from different water bodies and sites in three consecutive year’s i.e 2015-2017.The population status of G.hamiltonii has recorded as decreasing in Sindh due to habitat destruction,eutrophication,agricultural farming and some other anthropogenic activities.This species is mostly used as pet and the poachers mostly carrying this species for trade in East Asian countries.The globally illegal trading hubs of this species are Bangkok,Taiwan and Hong Kong.More and powerful actions and efforts are needed to raise awareness of smuggling of wildlife,with a specific need of formal memorandums of understanding(MOUs)are strongly encouraged south Asian and east Asian countries to control illegal trade between the countries and territories along the trade route of Bangladesh,India,Pakistan,Thailand,Hong Kong and Taiwan to improve cross border enforcement.展开更多
The long-term response (LTR) to light-quality gradients improves performance and survival of plants in dense stands. It involves redox-controlled transcriptional regulation of the plastome-encoded genes psaAB (enco...The long-term response (LTR) to light-quality gradients improves performance and survival of plants in dense stands. It involves redox-controlled transcriptional regulation of the plastome-encoded genes psaAB (encoding the P700 apoproteins of photosystem I) and psbA (encoding the D1 protein of photosystem II) and requires the action of plastidlocalized kinases. To study the potential impact of phosphorylation events on plastid gene expression during the LTR, we analyzed mustard seedlings acclimated to light sources favoring either photosystem I or photosystem II. Primer extension analyses of psaA transcripts indicate that the redox regulation occurs at the principal bacterial promoters, suggesting that the plastid encoded RNA polymerase (PEP) is the target for redox signals. Chloroplast protein fractions containing PEP and other DNA-binding proteins were purified from mustard via heparin-Sepharose chromatography. The biochemical properties of these fractions were analyzed with special emphasis on promoter recognition and specificity, phosphorylation state, and kinase activity. The results demonstrate that the LTR involves the action of small DNA-binding proteins; three of them exhibit specific changes in the phosphorylation state. Auto-phosphorylation assays, in addition, exhibit large differences in the activity of endogenous kinase activities. Chloroplast run-on transcription experiments with the kinase inhibitor H7 and the reductant DTT indicate that phosphorylation events are essential for the mediation of redox signals toward psaA and psbA transcription initiation, but require the synergistic action of a thiol redox signal. The data support the idea that redox signals from the thylakoid membrane are linked to gene expression via phosphorylation events; however, this mediation appears to require a complex network of interacting proteins rather than a simple phosphorelay.展开更多
Natural illumination conditions are highly variable and because of their sessile life style, plants are forced to acclimate to them at the cellular and molecular level. Changes in light intensity or quality induce cha...Natural illumination conditions are highly variable and because of their sessile life style, plants are forced to acclimate to them at the cellular and molecular level. Changes in light intensity or quality induce changes in the reduction/oxidation (redox) state of the photosynthetic electron chain that acts as a trigger for compen- satory acclimation responses comprising functional and structural adjustments of photosynthesis and metabolism. Such responses include redox-controlled changes in plant gene expression in the nucleus and organelles. Here we describe a strategy for the identification of early redox-regulated genes (ERGs) in the nucleus of the model organism Arabidopsis thaliana that respond significantly 30 or 60 min after the generation of a reduction signal in the photosynthetic electron transport chain. By comparing the response of wild-type plants with that of the acclimation mutant stn7, we could specifically identify ERGs. The results reveal a significant impact of chloroplast redox signals on distinct nuclear gene groups including genes for the mitochondrial electron transport chain, tetrapyrrole biosynthesis, carbohydrate metabolism, and signaling lipid synthesis. These expression profiles are clearly different from those observed in response to the reduction of photosynthetic electron transport by high light treatments. Thus, the ERGs identified are unique to redox imbalances in photosynthetic electron transport and were then used for analyzing potential redox-responsive cis-elements, trans-factors, and chromosomal regulatory hot spots. The data identify a novel redox-responsive element and indicate extensive redox control at transcriptional and chromosomal levels that point to an unprecedented impact of redox signals on epigenetic processes.展开更多
文摘In the present work on population status,threats and conservation of the spotted pond turtle;Geoclemys hamiltonii(Gray,1830)(Geoemydidae)was conducted in Thatta,Sujawal and Badin districts of Sindh province of Pakistan.A total number of 277 live specimens of G.hamiltonii from southeast province(Sindh)of Pakistan have been collected from different water bodies and sites in three consecutive year’s i.e 2015-2017.The population status of G.hamiltonii has recorded as decreasing in Sindh due to habitat destruction,eutrophication,agricultural farming and some other anthropogenic activities.This species is mostly used as pet and the poachers mostly carrying this species for trade in East Asian countries.The globally illegal trading hubs of this species are Bangkok,Taiwan and Hong Kong.More and powerful actions and efforts are needed to raise awareness of smuggling of wildlife,with a specific need of formal memorandums of understanding(MOUs)are strongly encouraged south Asian and east Asian countries to control illegal trade between the countries and territories along the trade route of Bangladesh,India,Pakistan,Thailand,Hong Kong and Taiwan to improve cross border enforcement.
文摘The long-term response (LTR) to light-quality gradients improves performance and survival of plants in dense stands. It involves redox-controlled transcriptional regulation of the plastome-encoded genes psaAB (encoding the P700 apoproteins of photosystem I) and psbA (encoding the D1 protein of photosystem II) and requires the action of plastidlocalized kinases. To study the potential impact of phosphorylation events on plastid gene expression during the LTR, we analyzed mustard seedlings acclimated to light sources favoring either photosystem I or photosystem II. Primer extension analyses of psaA transcripts indicate that the redox regulation occurs at the principal bacterial promoters, suggesting that the plastid encoded RNA polymerase (PEP) is the target for redox signals. Chloroplast protein fractions containing PEP and other DNA-binding proteins were purified from mustard via heparin-Sepharose chromatography. The biochemical properties of these fractions were analyzed with special emphasis on promoter recognition and specificity, phosphorylation state, and kinase activity. The results demonstrate that the LTR involves the action of small DNA-binding proteins; three of them exhibit specific changes in the phosphorylation state. Auto-phosphorylation assays, in addition, exhibit large differences in the activity of endogenous kinase activities. Chloroplast run-on transcription experiments with the kinase inhibitor H7 and the reductant DTT indicate that phosphorylation events are essential for the mediation of redox signals toward psaA and psbA transcription initiation, but require the synergistic action of a thiol redox signal. The data support the idea that redox signals from the thylakoid membrane are linked to gene expression via phosphorylation events; however, this mediation appears to require a complex network of interacting proteins rather than a simple phosphorelay.
文摘Natural illumination conditions are highly variable and because of their sessile life style, plants are forced to acclimate to them at the cellular and molecular level. Changes in light intensity or quality induce changes in the reduction/oxidation (redox) state of the photosynthetic electron chain that acts as a trigger for compen- satory acclimation responses comprising functional and structural adjustments of photosynthesis and metabolism. Such responses include redox-controlled changes in plant gene expression in the nucleus and organelles. Here we describe a strategy for the identification of early redox-regulated genes (ERGs) in the nucleus of the model organism Arabidopsis thaliana that respond significantly 30 or 60 min after the generation of a reduction signal in the photosynthetic electron transport chain. By comparing the response of wild-type plants with that of the acclimation mutant stn7, we could specifically identify ERGs. The results reveal a significant impact of chloroplast redox signals on distinct nuclear gene groups including genes for the mitochondrial electron transport chain, tetrapyrrole biosynthesis, carbohydrate metabolism, and signaling lipid synthesis. These expression profiles are clearly different from those observed in response to the reduction of photosynthetic electron transport by high light treatments. Thus, the ERGs identified are unique to redox imbalances in photosynthetic electron transport and were then used for analyzing potential redox-responsive cis-elements, trans-factors, and chromosomal regulatory hot spots. The data identify a novel redox-responsive element and indicate extensive redox control at transcriptional and chromosomal levels that point to an unprecedented impact of redox signals on epigenetic processes.