Aa. Taylor et al., MATURATION AND SECRETION OF A SERINE PROTEINASE IS ASSOCIATED WITH EVENTS OF LATE MICROSPOROGENESIS, Plant journal, 12(6), 1997, pp. 1261-1271
An antiserum against meiotic proteins which bind to DNA cellulose was
generated as a tool to assist the identification and purification of m
icrosporogenesis-specific proteins. In immunoblotting experiments, thi
s antiserum identified three meiotic proteins which are differentially
expressed in anthers during microsporogenesis. One of these proteins
was purified and characterized by biochemical and immunological techni
ques. This 82 kDa protein is synthesized as a preproprotein, acquires
glycans as it moves through the endoplasmic reticulum and Golgi body,
and is secreted into the anther locule. Immunocytochemical experiments
demonstrate that the protein is expressed primarily in tapetal cells,
and reaches peak concentrations as the microsporocytes reach the tetr
ad stage. Zymogram analyses and protein sequence comparisons indicate
that the protein is a member of the serine proteinase family. The poss
ible roles of the proteinase in microsporogenesis and pollen developme
nt are discussed.