Intron-mediated enhancement as a method for increasing transgene expression levels in barley

Area of Science:

• Plant Biotechnology
• Molecular Biology
• Genetics

Background:

• Optimizing transgene expression is crucial for producing sufficient quantities of transgenic proteins in plants.
• Low expression levels can limit the utility of genetically modified crops.
• The Ubi1 promoter is commonly used but may not always confer optimal expression levels.

Purpose of the Study:

• To investigate the potential of intron inclusion to enhance transgene expression in barley (Hordeum vulgare).
• To determine if specific introns can increase expression beyond that provided by the Ubi1 promoter.
• To assess the stability of enhanced expression in subsequent generations.

Main Methods:

• Two different introns (RpoT-i4 from maize and UBQ10-i1 from Arabidopsis) were inserted into the firefly luciferase (luc) coding sequence.
• Constructs were transformed into barley using Agrobacterium-mediated transformation.
• Luciferase activity and mRNA transcript levels were quantified in independent transformant populations and their progenies (T1 and T2).

Main Results:

• Both cloned introns significantly increased luciferase activity in barley.
• Quantitative reverse-transcription polymerase chain reaction confirmed increased accumulation of luciferase mRNA transcripts.
• Enhanced transgene expression levels remained stable in the T1 and T2 generations.

Conclusions:

• Intron-mediated enhancement is an effective strategy for boosting transgene expression in barley.
• This technique provides a valuable tool for achieving high and stable transgene expression in crop plants.
• Intron inclusion offers a means to overcome limitations of constitutive promoters like Ubi1.