A rapid and highly efficient sorghum transformation strategy using GRF4-GIF1/ternary vector system

Area of Science:

• Plant biotechnology
• Crop improvement
• Genetic engineering

Background:

• Sorghum is a vital crop for food, forage, wine, and biofuel.
• Efficient genetic transformation is crucial for sorghum improvement but remains challenging.
• Existing methods like BBM-WUS have limitations in efficiency and speed.

Purpose of the Study:

• To enhance sorghum transformation efficiency and speed.
• To investigate the impact of GRF4-GIF1 and GRF5 on sorghum transformation.
• To develop an efficient CRISPR/Cas9 gene-editing tool for sorghum.

Main Methods:

• Investigated GRF4-GIF1 and GRF5 chimeras for sorghum transformation.
• Utilized a ternary vector system with helper plasmid pVS1-VIR2.
• Developed a sorghum CRISPR/Cas9 gene-editing tool based on the enhanced system.

Main Results:

• GRF4-GIF1 and GRF5 significantly improved sorghum transformation efficiency and accelerated the process to under two months.
• The combination of GRF4-GIF1 with pVS1-VIR2 achieved a 38.28% transformation efficiency, a 7.71-fold increase.
• Overexpression of GRF4-GIF1 did not cause noticeable growth defects.
• The developed CRISPR/Cas9 system achieved 41.36% gene mutation efficiency, enabling T0 null mutant generation.

Conclusions:

• GRF4-GIF1 and GRF5 are effective tools for enhancing sorghum transformation efficiency and speed.
• The GRF4-GIF1/ternary vector system provides a robust platform for sorghum genetic improvement.
• This system facilitates efficient CRISPR/Cas9-mediated gene editing in sorghum, enabling rapid generation of mutants.