Sugarcane DIRIGENT and O-METHYLTRANSFERASE promoters confer stem-regulated gene expression in diverse monocots

Abstract

Transcription profiling analysis identified Saccharum hybrid DIRIGENT (SHDIR16) and O-METHYLTRANSFERASE (SHOMT), putative defense and fiber biosynthesis-related genes that are highly expressed in the stem of sugarcane, a major sucrose accumulator and biomass producer. Promoters (Pro) of these genes were isolated and fused to the β-glucuronidase (GUS) reporter gene. Transient and stable transgene expression analyses showed that both ProDIR16:GUS and ProOMT:GUS retain the expression characteristics of their respective endogenous genes in sugarcane and function in orthologous monocot species, including rice, maize and sorghum. Furthermore, both promoters conferred stem-regulated expression, which was further enhanced in the stem and induced in the leaf and root by salicylic acid, jasmonic acid and methyl jasmonate, key regulators of biotic and abiotic stresses. ProDIR16 and ProOMT will enable functional gene analysis in monocots, and will facilitate engineering monocots for improved carbon metabolism, enhanced stress tolerance and bioenergy production. © Springer-Verlag 2010.