Distribution patterns of neutral invertase and sugar contentin sugarcane internodal tissues

Neutral invertase (NI, EC 3.2.1.26) and sugars were extracted from the developing culm tissues of sugarcane. Tissues were divided according to developmental stage (internodes 3, 6 and 9) and anatomical differentiation (enriching for elongating, vascular or storage tissues). The lowest sucrose content was found in the core of the bottom of each of the internodes. The ratio between the two hexoses, glucose and fructose, and sucrose was highest in the young internodes and was also significantly different between the top and bottom parts of the young internodes. There was a significant correlation between sucrose content and NI and this was largely due to a tighter association between the two components in the bottom of the internodes.