Plant Science Research Division, Agricultural Research Service, United States Department of Agriculture and Department of Agronomy, Purdue University, Lafayette, Indiana 47907.
Plant Physiol. 1972 Feb;49(2):203-6. doi: 10.1104/pp.49.2.203.
Invertases of the placento-chalazal and pedicel tissues are much more active than invertase from the pericarp of Zea mays L. kernels 12 to 40 days after pollination. Sucrose synthetase was not detected in the pedicel or placento-chalazal tissues. Sucrose content and percentage increased in the pedicel with advancing kernel age. Hexoses accounted for over half of the sugars extracted from the placento-chalazal tissues. These data are consistent with the hypothesis that sucrose translocated to the pedicel is hydrolyzed by acid invertase(s) prior to entry of sugar into the endosperm tissue. The placentochalazal tissue appears to be the primary site of sucrose inversion with the pedicel invertase contributing more or less to this process depending on kernel age.
授粉后 12 至 40 天，玉米子粒的胎座-珠柄组织中的转化酶比果皮中的转化酶活性高得多。在珠柄和胎座组织中未检测到蔗糖合酶。随着子粒的成熟，蔗糖含量和百分率在珠柄中增加。己糖占从胎座-珠柄组织中提取的糖的一半以上。这些数据与蔗糖被运送到珠柄后被酸性转化酶水解的假说一致，在此之后糖才进入胚乳组织。胎座-珠柄组织似乎是蔗糖转化的主要部位，而珠柄转化酶或多或少地参与了这一过程，这取决于子粒的年龄。
