Sugar composition of pollen grain and pollen tube cell walls

The sugar composition of pollen grain and pollen tube cell walls was studied for Camellia japonica, C. sasanqua, C. sinensis, Tulipa gesneriana and Lilium longiflorum. In all species, the main components of pollen grain walls were arabinose, galactose, glucose and uronic acid. On the other hand, the pollen tube walls consisted mostly of glucose. The pollen tube wall of C. japonica was fractionated into hemicellulose, α-cellulose and pectic substance fractions in yields of 61, 19 and 3 %, respectively. The hemicellulose fraction was composed essentially of glucose. The sugar composition of the pollen tube wall was not influenced by the nature of exogenously supplied sugars. Rapid growth of the pollen tube seemed to correlate with the synthesis of hemicellulosic glucan.