High-level expression of sucrose inducible sweet potato sporamin gene promoter: β-glucuronidase fusion gene in transgenic Nicotiana plumbaginifolia

This is the authors' abstract. We don't add key points for this paper.

We produced transgenic Nicotiana plumbaginifolia plants which contained Spomin (sporamin minimal promoter)-GUS fused chimeric gene constructs with 5 types of signal sequences, such as cytosol, apoplast, ER, vacuole and plastid, and analyzed the GUS expression patterns after sucrose treatment. Spomin induced extremely high GUS activities after 6% and 10% sucrose treatment, especially in leaves. The high GUS activities were observed in leaves of the Spomin-ER-GUS construct treated with 6% or 10% sucrose. These were over 200 times higher than those in leaves with the 35S promoter-ER-GUS construct. The 10% sucrose treatment significantly altered GUS activities in all Spomin and 35S promoter constructs compared with those in the 6% sucrose treatment; some increased and some decreased. GUS activities in 2 months old plants were almost the same as 8 months old plants, indicating that GUS expression driven by Spomin was stably maintained. Also, even when sucrose treatment was stopped, GUS gene expression by Spomin continued for 10 days.