Successful fertility restoration in male-sterile barnase line by optimal expression of barstar gene for hybrid-rice seed production

ABSTRACT

The basic requirement for the barnase-barstar-based hybrid-seed production technology is the availability of stable male-sterile barnase and restorer barstar lines. Development of two rice (Oryza sativa) male-sterile barnase lines has been earlier reported from our lab. Complete restoration of male fertility in transgenic male-sterile lines has always been a challenging task for molecular breeders. In the present study, we have reported the successful fertility restoration in male-sterile barnase lines using barstar restorer lines generated through two completely different tapetum-specific promoters. The barstar lines were not able to restore male fertility in one barnase line but did restore it in the other barnase line. The male-sterile barnase line and its corresponding restorer line could be diversified into appropriate combiners for heterosis rice breeding.

KEYWORDS:

• Barnase gene
• barstar gene
• fertility restorer line
• Male-sterile line
• rice hybrid-seed production
• Tapetum-specific promoter

Acknowledgments

We thank Prof. Madan Mohan (University of Delhi, New Delhi) for providing lab support for our work. We thank Prof. Deepak Pental and Prof. Pradeep Kumar Burma (University of Delhi, New Delhi) for providing some basic constructs, which were modified in our work. We thank Prof. Sanjay Kapoor, University of Delhi, New Delhi for providing OsRTS(IR64) and OsAgo3 promoter. PK would like to thank University Grant Commission, India, for Dr. D.S. Kothari post-doctoral fellowship [File no. 13-444/2011(BSR)] and Science and Engineering Research Board, Department of science and technology, India for Young Scientist Fast track grant (SB/YS/LS-104/2014). PK likes to thank Guru Gobind Singh Indraprastha University, New Delhi, India, and University of Delhi, India, for support in execution of project.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Author contributions

PK conceived, designed and performed the experiments. PK and RSP wrote the manuscript.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/15427528.2022.2163445

Additional information

Funding

Pravin Kumar - Dr. D.S. Kothari post-doctoral fellowship, University Grant Commission, India. [File no. 13-444/2011(BSR)]Pravin Kumar: Young Scientist Fast track grant, Science and Engineering Research Board, Department of science and technology, India. (SB/YS/LS-104/2014; University Grants Commission