RESUMO
First ever 3-day aircraft observations of vertical profiles of Black Carbon (BC) were obtained during the Cloud Aerosol Interaction and Precipitation Enhancement Experiment (CAIPEEX) conducted on 30(th) August, 4(th) and 6(th) September 2009 over Guwahati (26° 11'N, 91° 44'E), the largest metropolitan city in the Brahmaputra River Valley (BRV) region. The results revealed that apart from the surface/near surface loading of BC due to anthropogenic processes causing a heating of 2â K/day, the large-scale Walker and Hadley atmospheric circulations associated with the Indian summer monsoon help in the formation of a second layer of black carbon in the upper atmosphere, which generates an upper atmospheric heating of ~2 K/day. Lofting of BC aerosols by these large-scale circulating atmospheric cells to the upper atmosphere (4-6 Km) could also be the reason for extreme climate change scenarios that are being witnessed in the BRV region.
RESUMO
Red rot is a serious disease of sugarcane caused by the fungus Colletotrichum falcatum imposing a considerable economic loss annually in all sugarcane-producing countries. In this study, we analyzed the early resistance response of sugarcane to red rot fungus by comparing the differences between control and inoculated stalk tissues. Differential display reverse transcription polymerase chain reaction (DD-RT-PCR) was employed to identify altered expression of genes in disease-resistant cv Co 93009, in response to pathogen infection. DD-RT-PCR identified 300 differentially expressed transcripts of which 112 were selected for further analysis. Cloning and sequence analysis of the isolated cDNA fragments resulted in functional categorization of these clones into five categories, of which the defense/stress/signaling group was the largest, with clones homologous to genes known to be actively involved in various pathogenesis-related functions in plant species. This group showed overexpression of several transcripts related to ethylene-mediated and jasmonic acid pathway of plant defense mechanisms. Of the 112 expressed sequence tags, validation of expression was carried out for five important genes whose role in plant defense mechanisms is well established. This is the first report of Colletotrichum-mediated gene regulation in sugarcane which has provided a set of candidate genes for detailed molecular dissection of signaling and defense responses in tropical sugarcane during the onset of red rot resistance.
Assuntos
Colletotrichum/fisiologia , Resistência à Doença/genética , Regulação da Expressão Gênica de Plantas/imunologia , Doenças das Plantas/microbiologia , Saccharum/genética , Saccharum/imunologia , Adesão Celular , Colletotrichum/citologia , Saccharum/microbiologiaRESUMO
An effort has been made to isolate individual catechin compounds from green tea leaves in their pure form by electrophoresis. In the present study total polyphenol extraction was carried out initially and estimated through spectrophotometric and HPLC methods. Extracted polyphenol was separated on 0.7% agarose gel and visualized at 360 nm. Fragmented individual compounds were gel eluted with methanol and confirmed as (-)-epigallocatechin (EGC), (-)-epicatechin (EC), (-)-epicatechin gallate (ECG), and (-)-epigallocatechin gallate (EGCG) by HPLC. The method developed describes a suitable method for the isolation of valuable molecules in tea.