| Major latex protein (MLP) is a member of the Bet v 1 superfamily and is involved in various plant stress responses. In this study, the promoter of the mulberry MaMLP423 gene, designated pMaMLP423, was analyzed using bioinformatics, cloned, and functionally characterized. The results showed that pMaMLP423 contains not only core cis-acting elements such as the TATA-box and CAAT-box, but also multiple elements responsive to light (Box 4, TCT-motif, GA-motif), abscisic acid (ABRE, AAGAA-motif), ethylene (ERE), drought (MYB, MBS), and wounding (WUN-motif). Plant expression vectors containing the full-length promoter (pMaMLP423) and its truncated versions (pMaMLP423ΔS1 and pMaMLP423ΔS2) were constructed and transiently expressed in tobacco. qPCR and histochemical GUS staining demonstrated that all three constructs could drive the expression of the downstream GUS gene. However, the promoter activities of the ΔS1 and ΔS2 deletions were both lower than that of the full-length pMaMLP423. Exogenous application of ABA and ethylene significantly induced the expression of MaMLP423. This study provides a foundation for further investigation of the regulatory function of the MaMLP423 promoter. |
