CLAVATA3 / EMBRYO   SURROUNDING   REGION (CLE) Gene Family in Potato (Solanum   tuberosum L.): Identification and Expression Analysis.

CLE genes encode a group of small secretory peptides, which regulate cell proliferation and differentiation in plants. CLE genes have been studied in many plants; however, little is known about this gene family in potato. In this study, we characterized members of the CLE gene family in potato Solanum tuberosum (StCLE) and comprehensively analyzed their phylogenetic relationships, structure, and expression patterns. Using available transcriptomic data, we found a relative high expression level of StCLE8, StCLE12, and StCLE13 in stolons and tubers. Real-time PCR analysis showed that the StCLE23 gene was upregulated by water deficiency, whereas the expression of StCLE4 and StCLE10 was induced by nitrogen supply. Besides that, using data from transcriptomic studies obtained previously for plants with the induction the StBEL5 gene, a positive regulator of tuber development, we found that StCLE4 was among genes upregulated in response to StBEL5 induction, suggesting that StCLE4 could be a target of StBEL5 transcription factor. However, we did not reveal a direct binding of StBEL5 to the regulatory sequences of StCLE4 using yeast one-hybrid assay. Taken together, our data provide basic information for future functional studies of CLE peptides in potato growth and tuberization and in response to various environmental stimuli. [ABSTRACT FROM AUTHOR]