A novel mannose-based selection system for plant transformation using celery mannose-6-phosphate reductase gene

Area of Science:

• Plant Biotechnology
• Molecular Biology
• Genetics

Background:

• Selectable marker genes are crucial for identifying transformed plant cells.
• The mannitol-producing celery mannose-6-phosphate reductase gene (M6PR) was investigated for its potential as a novel selectable marker.
• Understanding plant species-specific responses to mannose is key for marker gene application.

Purpose of the Study:

• To evaluate the celery M6PR gene as a selectable marker in plant transformation.
• To determine if M6PR facilitates positive or negative selection in different plant species.
• To explore the potential of M6PR for improving plant salt tolerance.

Main Methods:

• Agrobacterium tumefaciens-mediated transformation of Arabidopsis and tobacco with the M6PR gene.
• Mannose-tolerance assays on transgenic seeds and leaf explants.
• Northern blot analysis to confirm M6PR gene expression.
• Verification of mannitol accumulation in transgenic tobacco.

Main Results:

• M6PR enabled positive selection in Arabidopsis, with transgenic seeds germinating on 2 g/L mannose while wild-type seeds did not.
• M6PR facilitated negative selection in tobacco, with 30 g/L mannose inhibiting germination and growth of transgenic seeds and leaves.
• Northern blot confirmed M6PR expression, and mannitol accumulation verified gene activity in tobacco.
• Transgenic tobacco with antisense M6PR or plasmid control showed no altered mannose sensitivity.

Conclusions:

• The celery M6PR functions as a versatile selectable marker, offering positive selection in mannose-sensitive plants and negative selection in mannose-tolerant plants.
• M6PR-mediated selection strategies are adaptable for various plant transformation systems.
• Mannitol accumulation by M6PR suggests its potential for enhancing plant salt tolerance.