Figure 10.

Proposed working model for CLE19 in the regulation of anther development. A, In wild-type anthers, CLE19 peptides interact with their unknown receptor to negatively regulate the AMS-MYB103-MS1 transcriptional cascade to prevent their deleterious overexpression, which triggers the normal expression of downstream exine formation-related genes, and subsequently regulate the formation of normally well-organized pollen exine. B, In DN-CLE19 anthers, CLE19 peptides without function competitively interact with the unknown CLE19 receptor, which blocks or obviously reduces signal transduction from the functional CLE19 to its downstream molecules, leading to the deleterious overexpression of the AMS-MYB103-MS1 transcriptional cascade and downstream exine formation-related genes, and subsequently affect normal pollen exine formation. C, In CLE19-OX anthers, overexpression of CLE19 peptide strengthens the suppression of transcription factor gene expression, resulting in abnormal pollen exine formation.