UV-B radiation mediated alterations in the nitrate assimilation pathway of crop plants. 1.. Kinetic characteristics of nitrate reductase

Title:

UV-B radiation mediated alterations in the nitrate assimilation pathway of crop plants. 1.. Kinetic characteristics of nitrate reductase

Creator:

Balakumar, T., Selvakumar, V., Sathiameena, K., Murugu Ilanchezhian, C., and Paliwal, K.

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:6fa33e56-6779-454e-818f-8f4370089629
uuid:6fa33e56-6779-454e-818f-8f4370089629
issn:10.1023/A:1007116012323
doi:10.1023/A:1007116012323

Subject:

carotenoids, chlorophyll, fresh and dry mass, leaf area, root, shoot, and Vigna unguiculata

Type:

model:article and TEXT

Format:

bez média and svazek

Description:

The kinetics and other characteristics of nitrate reductase (NR, EC 1.6.6.1) in cowpea [Vigna unguiculata (L.) Walp.] seedlings irradiated with biologically effective UV-B radiation (280-320 nm, 3.2 W m-2 s-1) were recorded. The in vivo and in vitro NR activities were inhibited by 34 and 41 % under UV-B treatment, respectively. Both Vmax and Km for the substrate were enhanced by UV-B radiation. The Km for nitrate increased from 1.2 to 1.7 mM after the UV-B irradiation. The change in Km for NADH was from 0.12 to 0.17 mM. The increases in Km indicate that UV-B radiation seriously changes the topology of NR, particularly with respect to the nitrate and NADH binding sites. The rate of NR turnover indicates the extent of damage inflicted by UV-B radiation on the nitrate metabolism. The half-life (t1/2) of NR was reduced from 7 to 4 h in the UV-B treated seedlings. UV-B also inhibited the kinetics of nitrate uptake by plants: its Km increased from 0.08 to 0.12 mM. and T. Balakumar ... [et al.].

Language:

Multiple languages

Rights:

http://creativecommons.org/licenses/by-nc-sa/4.0/
policy:public

Coverage:

459-467

Source:

Photosynthetica | 1999 Volume:37 | Number:3

Harvested from:

CDK

Metadata only:

false