We have located links that may give you full text access.
JOURNAL ARTICLE
RESEARCH SUPPORT, NON-U.S. GOV'T
Nitrogen storage and remobilization in Brassica napus L. during the growth cycle: effects of methyl jasmonate on nitrate uptake, senescence, growth, and VSP accumulation.
Journal of Experimental Botany 2002 May
The role of methyl jasmonate (MeJa) in promoting senescence has been described previously in many species, but it has been questioned in monocarpic species whether induced senescence is a result of a potential death hormone like MeJa, or a consequence of an increased metabolic drain resulting from the growth of reproductive tissue. In oilseed rape (Brassica napus L.), a polypeptide of 23 kDa has been recently identified as a putative vegetative storage protein (VSP). This polypeptide could be used as a storage buffer between N losses from senescing leaves putatively promoted by methyl jasmonate that might be produced by flowers, and grain filling which occurs later on, while N uptake is strongly reduced. In order to describe causal relationships during Brassica napus L. plant responses to MeJa treatment, a kinetic experiment was performed to determine the order and the amplitude with which general processes such as growth, photosynthesis, chlorophyll content, N uptake, and N storage under the form of the 23 kDa VSP are affected. One of the most immediate consequences of MeJa treatment was the strong reduction of nitrate uptake within 6 h, relative to control plants. However, this was not a specific effect as K(+) uptake was similarly affected. Photosynthesis was reduced later (after 24 h), while chlorophyll content as well as leaf growth also decreased in a similar way. Moreover, this was concomitant with a remobilization of endogenous unlabelled N from senescing leaves to roots. Accumulation of the 23 kDa VSP was induced in the taproot after 24 h of MeJa treatment and was increased 10-fold within 8 d. On the other hand, the reversible effect of a MeJa pretreatment was tested in the long term (i.e. along the growth cycle) using plants previously grown in field conditions induced for flowering. Results show that a MeJa pulse induced a reversible effect on N uptake inhibition. In parallel, protein immunologically related to the 23 kDa VSP was detected in stems with a similar molecular weight (23 kDa), and in flowers and leaves with a molecular weight of 24 kDa. This accumulation was concomitant with the remobilization of both subunits of Rubisco. During stem and pod development, this protein induced by MeJa is fully hydrolysed. The external and intermittent supply of MeJa mimic some of the plant physiological processes previously reported under natural conditions. This suggests that in oilseed rape, methyl jasmonate could be considered as a possible monocarpic senescence factor while accumulation/mobilization of the 23 kDa VSP in taproot could be a marker for the cessation of N uptake and the initiation of a massive leaf senescence.
Full text links
Related Resources
Trending Papers
Heart failure with preserved ejection fraction: diagnosis, risk assessment, and treatment.Clinical Research in Cardiology : Official Journal of the German Cardiac Society 2024 April 12
Proximal versus distal diuretics in congestive heart failure.Nephrology, Dialysis, Transplantation 2024 Februrary 30
World Health Organization and International Consensus Classification of eosinophilic disorders: 2024 update on diagnosis, risk stratification, and management.American Journal of Hematology 2024 March 30
Efficacy and safety of pharmacotherapy in chronic insomnia: A review of clinical guidelines and case reports.Mental Health Clinician 2023 October
Get seemless 1-tap access through your institution/university
For the best experience, use the Read mobile app
All material on this website is protected by copyright, Copyright © 1994-2024 by WebMD LLC.
This website also contains material copyrighted by 3rd parties.
By using this service, you agree to our terms of use and privacy policy.
Your Privacy Choices
You can now claim free CME credits for this literature searchClaim now
Get seemless 1-tap access through your institution/university
For the best experience, use the Read mobile app