An elegant co-transformation strategy for recalcitrant wheat using morphogenic regulators.

Area of Science:

• Plant Biotechnology
• Agricultural Science
• Genetics

Background:

• Common wheat (Triticum aestivum L.) is a crucial global crop.
• Many elite wheat cultivars are recalcitrant to genetic transformation, impeding research and breeding efforts.

Purpose of the Study:

• To develop an efficient and simplified co-transformation strategy for recalcitrant wheat varieties.
• To overcome the limitations of existing genetic transformation methods in elite wheat cultivars.

Main Methods:

• A co-transformation approach using two Agrobacterium tumefaciens vectors: one for the gene-of-interest (GOI) and another for the morphogenic gene mTaGRF4-TaGIF1 (GOC).
• Mixing bacterial cultures carrying both vectors for simultaneous delivery into wheat cells.
• Assessing regeneration efficiency and transgene integration in recalcitrant varieties like Aikang58 and Xinong979.

Main Results:

• Co-transformation significantly improved regeneration efficiency in Aikang58 to ~37.38%.
• A high percentage of regenerants (~63.25%) successfully integrated both the GOI and GOC vectors.
• The method enabled the generation of transgenic lines expressing GUS and RUBY, and CRISPR-Cas9 edited mutants, demonstrating broad applicability.
• The strategy was successfully validated in the recalcitrant variety Xinong979.

Conclusions:

• The developed co-transformation strategy offers a technically advanced yet operationally simplified platform for genetic transformation of recalcitrant wheat.
• This method addresses a key challenge in wheat functional genomics and precision breeding.
• It provides a powerful tool for accelerating crop improvement in elite wheat cultivars.