Developing disease-resistant thermosensitive male sterile rice by multiplex gene editing

Area of Science:

• Plant genetics
• Agricultural biotechnology
• Molecular biology

Background:

• Developing high-quality, disease-resistant male sterile lines is crucial for hybrid rice breeding.
• Existing methods for creating sterile lines can be time-consuming and less efficient.

Purpose of the Study:

• To introduce mutations into key genes (TMS5, Pi21, Xa13) in rice using CRISPR/Cas9.
• To create transgene-free, homozygous triple mutants exhibiting thermosensitive genic male sterility (TGMS).
• To enhance resistance to rice blast and bacterial blight in the developed TGMS lines.

Main Methods:

• Utilized the CRISPR/Cas9 multiplex genome editing system.
• Targeted specific mutations in the TMS5, Pi21, and Xa13 genes.
• Screened for transgene-free homozygous mutants in the T1 generation.

Main Results:

• Successfully generated transgene-free homozygous triple mutants (tms5/pi21/xa13).
• The mutants exhibited thermosensitive genic male sterility (TGMS).
• Enhanced resistance to both rice blast and bacterial blight was observed.

Conclusions:

• Multiplex genome editing offers a convenient and effective approach for converting breeding materials into TGMS lines.
• This strategy significantly accelerates the development of sterile lines for hybrid rice breeding.
• The developed TGMS lines possess desirable traits for disease resistance and hybrid seed production.