Characteristics of in vivo nitrate reduction in the CAM plant Notonia grandiflora DC.

Title:

Characteristics of in vivo nitrate reduction in the CAM plant Notonia grandiflora DC.

Creator:

Balakumar, T., Thangavel, M., and Paliwal, K.

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:fa79843a-2321-4afa-bc07-d28bf6f037a5
uuid:fa79843a-2321-4afa-bc07-d28bf6f037a5
urnnbn:urn:nbn:cz:aba007-000fe6

Type:

model:internalpart and TEXT

Format:

print

Description:

Characteristics of in vivo nitráte reductase (NR, EC 1.6.6.1) activity in leaf tissue of the crassulacean acid metabolism (CAM) plant Notonia grandiflora DC. were determined. The pH optimum for the enzyme was 7.0. Among the five low molecular mass solvents tested, n-propanol was more effective in promoting NR activity. Supply of 1.0 % (v/v) M-propanol along with 0.5 % Triton X-100 was the most appropriate assay condition to bring about maximum NR activity (NRA), that was proportionally enhanced with duration of the incubation and mass of the leaf tissue. Leaf fragments of 2 to 4 mm slice width had maximal NRA. The highest NRA was obtained with 200 mM of nitráte supplied in the infiltration medium. NRA was higher in fully expanded, mature leaves than in tender and senescing leaves. The cellular nitráte content was strongly positively correlated with NRA in leaves of various physiological ages. The NRA/N03’ content ratio (index of nitráte utilization efQciency) was the highest for the tender leaves and the lowest for the senescing leaves. However, maximum total titratable acidity (malate production) was obtained for the fully expanded mature leaves in comparison with the other leaves. A positive and significant correlation (r = 0.92) was obtained between nitráte reduction and titratable acid content. The results are indicative of a possible role of nitráte reduction in the regulation of noctumal acid production in the CAM plants.

Language:

Multiple languages

Rights:

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

Coverage:

297-306 and 139-148

Source:

Photosynthetica | 1993 Volume:28 | Number:2

Harvested from:

CDK

Metadata only:

false