Abstract
The diurnal rhythm in NO3 - absorption by the intact soybean roots was investigated by using a continuous sampling system of the culture solution. During the day and night period, the soybean absorbed NO3 - almost linearly irrespective of the time or NO3 - concentration in the medium. The NO3 - absorption rate was found to be different between the day and night period, and the level in the night was about 60-75% of that in the daytime. The temporary interruption of NO3 - absorption was observed twice a day at dawn and dusk. It was suggested that this rhythmic pattern of NO3 - absorption was not directly controlled by the shoots, based on the fact that the rhythm appeared under on extended dark period or by the cutting of the shoots. The diurnal rhythm was also observed in the N concentration of the xylem exudate collected from decapitated roots. The NO3 - absorption was completely inhibited by the addition of a metabolic inhibitor such as CCCP or KCN, but the rate was not affected by DNP. Concomitant K+ e...
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.