ISSN:
1399-3054
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Biology
Notes:
GA3-treatment of dwarf maize seedlings resulted in the elongation of the leaf sheath and also an increase in α-amylase activity. Excised leaf sheaths did not respond to GA3 in leaf shealh length and α-amylase activity. Increase in the enzyme activity is always accompanied by an increase in the length of the leaf sheath. α-Amylase activity gradually increased as the growth of the first leaf proceeded, and a parallelism was found between the length of the leaf sheath and the enzyme activity, suggesting that the degree, of the enzyme activity depends on the length of the leaf sheath. On the other hand, IAA did not affect α-amylase activity while it promoted leaf sheath elongation. This suggests that elongation per se is not associated with the increase in α-amylase activity and that the enzyme-promoting effect is specific to gibberellin. Higher α-amylase activity and lower content of reducing sugars were detected in the older tissue of the leaf sheath, that is, in the upper half. This was the same for GAlrealed seedlings. The amount of reducing sugars was less in GA3-trealcd seedlings. Oxygen-uptake of the leaf sheath was higher in the upper half in both controls and GA3-treated seedlings. It was slightly higher in the latter than in the former. From these results it was discussed 1o conclude that the processes of the GA3-induced elongation and increase in α-amylase activity of the leaf sheath are independent of one another.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1399-3054.1970.tb08883.x
