Please wait, while we are loading the content...
Please wait, while we are loading the content...
| Content Provider | PubMed Central |
|---|---|
| Author | Mackown, Charles T. Volk, Richard J. Jackson, William A. |
| Abstract | The effects of accumulated [14N]nitrate and its utilization in decapitated, 5-day-old dark-grown corn roots on influx, accumulation, xylem deposition, and reduction of concurrently absorbed nitrate during an 18-hour exposure to 0.5 millimolar K15NO3 nutrient solution were examined. A 20-hour pretreatment in 15.0 millimolar K14NO3 high nitrate (HN) resulted in a 2-fold greater tissue nitrate level than pretreatment in 0.5 millimolar K14NO3 low nitrate (LN). Upon transfer to the 0.5 millimolar K15NO3 solution, the net nitrate uptake rate in HN roots after 2 hours was 52% of the LN rate, but increased to 93% at the end of the uptake period. Despite an enhanced [14N]nitrate efflux from HN roots to the uptake solution, the efflux differences between the two pretreatments did not compensate for the decrease in net nitrate uptake. The [15N]nitrate influx rate was initially restricted by 33% in the HN roots compared to LN roots, but it had decreased to 7% by the end of the 18-hour uptake period. At this time, the total tissue nitrate levels were similar for both pretreatments. The rate of accumulation of [15N]nitrate in the tissue was relatively constant for both pretreatments, but was 25% less in HN roots. Of the previously accumulated [14N]nitrate, 52 and 46% remained after 18 hours in the LN and HN roots, respectively. The [14N]nitrate decline for HN roots was initially more rapid than in the LN roots which was linear over time. Xylem transport and efflux more than accounted for the decline in [14N]nitrate of LN roots and all but 4% in the HN roots which was attributed to reduction. Compartmentation of the previously accumulated nitrate was evident from the higher atom per cent 15N of xylem nitrate compared to that of the tissue nitrate of both LN and HN roots. During the first 2 hours, xylem transport of [14N]nitrate by the HN roots was 49% greater than for LN roots, while [15N]nitrate transport was 9% less in HN roots compared to LN roots. Even though the reduction of [15N]nitrate in HN roots was 31% less than LN roots during the first 2 hours, [15N]nitrate was reduced more rapidly than the previously accumulated [14N]nitrate. After the first 4 hours, the relative partitioning of absorbed [15N]nitrate between accumulation, reduction, and translocation was similar regardless of pretreatment. |
| Starting Page | 133 |
| File Format | |
| ISSN | 15322548 |
| e-ISSN | 15322548 |
| Journal | Plant Physiology |
| Issue Number | 1 |
| Volume Number | 68 |
| Language | English |
| Publisher Date | 1981-07-01 |
| Access Restriction | Open |
| Subject Keyword | Research in Higher Education |
| Content Type | Text |
| Resource Type | Article |
| Subject | Genetics Physiology Plant Science |
National Digital Library of India (NDLI) is a virtual repository of learning resources which is not just a repository with search/browse facilities but provides a host of services for the learner community. It is sponsored and mentored by Ministry of Education, Government of India, through its National Mission on Education through Information and Communication Technology (NMEICT). Filtered and federated searching is employed to facilitate focused searching so that learners can find the right resource with least effort and in minimum time. NDLI provides user group-specific services such as Examination Preparatory for School and College students and job aspirants. Services for Researchers and general learners are also provided. NDLI is designed to hold content of any language and provides interface support for 10 most widely used Indian languages. It is built to provide support for all academic levels including researchers and life-long learners, all disciplines, all popular forms of access devices and differently-abled learners. It is designed to enable people to learn and prepare from best practices from all over the world and to facilitate researchers to perform inter-linked exploration from multiple sources. It is developed, operated and maintained from Indian Institute of Technology Kharagpur.
Learn more about this project from here.
NDLI is a conglomeration of freely available or institutionally contributed or donated or publisher managed contents. Almost all these contents are hosted and accessed from respective sources. The responsibility for authenticity, relevance, completeness, accuracy, reliability and suitability of these contents rests with the respective organization and NDLI has no responsibility or liability for these. Every effort is made to keep the NDLI portal up and running smoothly unless there are some unavoidable technical issues.
Ministry of Education, through its National Mission on Education through Information and Communication Technology (NMEICT), has sponsored and funded the National Digital Library of India (NDLI) project.
| Sl. | Authority | Responsibilities | Communication Details |
|---|---|---|---|
| 1 | Ministry of Education (GoI), Department of Higher Education |
Sanctioning Authority | https://www.education.gov.in/ict-initiatives |
| 2 | Indian Institute of Technology Kharagpur | Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project | https://www.iitkgp.ac.in |
| 3 | National Digital Library of India Office, Indian Institute of Technology Kharagpur | The administrative and infrastructural headquarters of the project | Dr. B. Sutradhar bsutra@ndl.gov.in |
| 4 | Project PI / Joint PI | Principal Investigator and Joint Principal Investigators of the project |
Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon |
| 5 | Website/Portal (Helpdesk) | Queries regarding NDLI and its services | support@ndl.gov.in |
| 6 | Contents and Copyright Issues | Queries related to content curation and copyright issues | content@ndl.gov.in |
| 7 | National Digital Library of India Club (NDLI Club) | Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach | clubsupport@ndl.gov.in |
| 8 | Digital Preservation Centre (DPC) | Assistance with digitizing and archiving copyright-free printed books | dpc@ndl.gov.in |
| 9 | IDR Setup or Support | Queries related to establishment and support of Institutional Digital Repository (IDR) and IDR workshops | idr@ndl.gov.in |
|
Loading...
|