Cereal Chem 51:825 - 828.  |  VIEW ARTICLE
Comparison of the Effect of Shrunken-4, Opague-2, Opaque-7, and Floury-2 Genes on the Zein Content of Maize During Endosperm Development.

C.-Y. Tsai and A. Dalby. Copyright 1974 by the American Association of Cereal Chemists, Inc. 

The starch-deficient mutant shrunken-4 (sh4) reduces the zein content of maize (Zea mays L.) endosperm in a pattern distinct, in two ways, from opaque-2, opaque-7 and floury-2. First, zein accumulation does not start in sh4 until 22 days after pollination, whereas other mutant and normal lines have synthesized approximately 30% of their final zein content by this time. Second, mature kernels of sh4 contain only 10% of the normal content of zein per kernel; the other mutants contain 25 to 50% of the normal content. It is not known whether this is a direct effect of the sh4 gene on zein synthesis, or a secondary consequence of defective starch metabolism.