Siyu Chen1,2, Na Zhang2, Ganghua Zhou2, Saddam Hussain2, Sajjad Ahmed2, Hainan Tian3, Shucai Wang4,5. 1. Laboratory of Plant Molecular Genetics & Crop Gene Editing, School of Life Sciences, Linyi University, 276000, Linyi, China. 2. Key Laboratory of Molecular Epigenetics of MOE, Northeast Normal University, 130024, Changchun, China. 3. Key Laboratory of Molecular Epigenetics of MOE, Northeast Normal University, 130024, Changchun, China. tianhainan2012@126.com. 4. Laboratory of Plant Molecular Genetics & Crop Gene Editing, School of Life Sciences, Linyi University, 276000, Linyi, China. wangshucai@yahoo.com. 5. Key Laboratory of Molecular Epigenetics of MOE, Northeast Normal University, 130024, Changchun, China. wangshucai@yahoo.com.
Abstract
BACKGORUND: Environmental 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. RESULTS: We 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. CONCLUSIONS: Our 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.
BACKGORUND: Environmental 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. RESULTS: We 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. CONCLUSIONS: Our 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.
Authors: Agustin Zsögön; Tomáš Čermák; Emmanuel Rezende Naves; Marcela Morato Notini; Kai H Edel; Stefan Weinl; Luciano Freschi; Daniel F Voytas; Jörg Kudla; Lázaro Eustáquio Pereira Peres Journal: Nat Biotechnol Date: 2018-10-01 Impact factor: 54.908
Authors: Le Cong; F Ann Ran; David Cox; Shuailiang Lin; Robert Barretto; Naomi Habib; Patrick D Hsu; Xuebing Wu; Wenyan Jiang; Luciano A Marraffini; Feng Zhang Journal: Science Date: 2013-01-03 Impact factor: 47.728