Knockout of the entire family of AITR genes in Arabidopsis leads to enhanced drought and salinity tolerance without fitness costs

BMC Plant Biology

Saddam Hussain¹  Na Zhang¹  Ganghua Zhou¹  Hainan Tian¹  Sajjad Ahmed¹  Shucai Wang²  Siyu Chen² 

[1] Key Laboratory of Molecular Epigenetics of MOE, Northeast Normal University, 130024, Changchun, China;Laboratory of Plant Molecular Genetics & Crop Gene Editing, School of Life Sciences, Linyi University, 276000, Linyi, China;Key Laboratory of Molecular Epigenetics of MOE, Northeast Normal University, 130024, Changchun, China;

关键词: ABA;    Abiotic stress;    AITRs;    Arabidopsis;    Gene editing;    Fitness cost;   

DOI  :  10.1186/s12870-021-02907-9

来源: Springer

【 摘 要 】

BackgorundEnvironmental stresses including abiotic stresses and biotic stresses limit yield of plants. Stress-tolerant breeding is an efficient way to improve plant yield under stress conditions. Genome editing by CRISPR/Cas9 can be used in molecular breeding to improve agronomic traits in crops, but in most cases, with fitness costs. The plant hormone ABA regulates plant responses to abiotic stresses via signaling transduction. We previously identified AITRs as a family of novel transcription factors that play a role in regulating plant responses to ABA and abiotic stresses. We found that abiotic stress tolerance was increased in the single, double and triple aitr mutants. However, it is unclear if the increased abiotic stress tolerance in the mutants may have fitness costs.ResultsWe report here the characterization of AITRs as suitable candidate genes for CRISPR/Cas9 editing to improve plant stress tolerance. By using CRISPR/Cas9 to target AITR3 and AITR4 simultaneously in the aitr256 triple and aitr1256 quadruple mutants respectively, we generated Cas9-free aitr23456 quintuple and aitr123456 sextuple mutants. We found that reduced sensitivities to ABA and enhanced tolerance to drought and salt were observed in these mutants. Most importantly, plant growth and development was not affected even in the aitr123456 sextuple mutants, in whom the entire AITR family genes have been knocked out, and the aitr123456 sextuple mutants also showed a wild type response to the pathogen infection.ConclusionsOur results suggest that knockout of the AITR family genes in Arabidopsis enhanced abiotic stress tolerance without fitness costs. Considering that knock-out a few AITRs will lead to enhanced abiotic stress tolerance, that AITRs are widely distributed in angiosperms with multiple encoding genes, AITRs may be targeted for molecular breeding to improve abiotic stress tolerance in plants including crops.

【 授权许可】

CC BY