The Miniature1 Seed Locus of Maize Encodes a Cell Wall Invertase Required for Normal Development of Endosperm and Maternal Cells in the Pedicel.

摘要: Collective evidence demonstrates that the Miniature1 (Mn1) seed locus in maize encodes an endosperm-specific isozyme of cell wall Invertase, CWI-2. The includes (1) isolation and characterization ethyl methanesulfonate-induced mn1 mutants with altered enzyme activity (2) a near-linear relationship between gene/dose invertase CWI-2 protein. In addition, molecular analyses showed cDNA clone incw2 maps to Mn1 differentiates six independent origin into two classes when RNA gel blot were used. We also report unexpected observations provide significant new insight physiological role its regulation developing seed. First, large proportion total (~90%) was dispensable (i.e., nonlimiting). However, below threshold level ~6% wild-type activity, endosperm controlled both sink strength as well developmental stability maternal cells pedicel rate-limiting manner. Our data suggest unusually tight coordinate control wall-bound soluble forms invertase, which are most likely encoded by separate genes, presumably through metabolic controls mediated sugars.