Effects of Plant Age, Ascorbate and Kinetin Applications on Nitrate Reductase Activity and Leaf Protein Content of Maize ( Zea mays L.) Plants Grown under Heat Stress

摘要

A glasshouse study was conducted to evaluate the effects of high temperature growth conditions on leaf nitrate reductase activity (NaR) and crude protein content in maize ( Zea mays L.) plants and how these effects are influenced by ascorbate and kinetin applications. Both leaf NaR and crude protein declined significantly with plant age (p>0.05). There were no definite similarities between the patterns of variation in NaR activity and crude protein content. However ascorbate applications (but not kinetin) increased the correlative effects between NaR and leaf protein contents, in plants that were grown under high temperature stress conditions. Both NaR activity and protein contents were positively correlated with temperature. These correlations were higher between NaR and temperature than they were between crude protein content and temperature.