Nitrate Reductase Activity and Nitrate Concentration in Cotton Plant Leaf Blades and Petioles
- Chang-chi Chu ,
- Lucy E. Graham and
- Louis A. Bariola
Greenhouse studies were conducted to determine the potential of nitrate reductase activity (NRA) as an indicator of the change of N concentration of cotton (Gossypium hirsutum L.) shoots. The results showed that cotton petiole in vivo NRA was not significantly different from NRA in leaf blades during vegetative growth. Nitrate reductase activity (in vivo) in cotton petioles was significantly higher than in leaf blades during reproductive growth. When plants were in the three-mature-leaf stage, petiole NRA contributed 16% of total cotton shoot NRA. The petiole biomass was 14% of total shoot fresh weight and 8% of total shoot dry weight. Petiole NRA of plants in the vegetative growth stage increased from 39 to 68 pmol NO−2 FW (fresh weight) s−l when supplemented with nitrate-N. These results indicate that cotton petiole NRA is significant and its assay has potential for incorporation into monitoring systems that determine the change of N concentration in cotton shoots.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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