Gamma-aminobutyric acid(GABA) releases seed dormancy by orchestrating abscisic acid and gibberellin metabolism and signaling

【作者】 王晓婷； 宗娜； 王轩； 牛军鹏； 张笑； 舒凯； 王国栋； 惠伟；

【机构】 陕西省西安植物园,陕西省植物研究所； 陕西师范大学生命科学学院,西部果品资源高值利用教育部工程研究中心； 西北工业大学生态环境学院-陕西省秦岭生态智能化监测与保护重点实验室；

【摘要】 Seed dormancy release, regulated by abscisic acid(ABA) and gibberellin(GA), is crucial for plant growth and yield. Gamma-aminobutyric acid(GABA) is reported to regulate adaption to stresses in plant. However, its role in seed dormancy release remains elusive. Here, we reported that seed dormancy release was impaired in seeds lacking GABA biosynthesis gene GAD2, while enhanced in seeds deficient in GABA inactivate gene GABA-T, indicating that GABA positively regulated seed dormancy release. Further, ABA was found to antagonize GABA-facilitated seed dormancy release, and GABA failed to alleviate seed dormancy in GA deficiency mutant ga1-t. Analysis of mutants defective in ABA and GA biosynthesis revealed that seed dormancy release, characterized as decreased ABA content and increased GA3content, was suppressed in gad2 while enhanced in gaba-t1-1 mutant. Mechanistically,GABA was shown to promote GA3 biosynthesis by upregulating GA20ox1 expression, while simultaneously repressing ABA biosynthesis by downregulating NCED6 and upregulating CYP707A2 transcription. GABA also amplified GA signaling and inhibited ABA signaling by downregulating genes expression of DELLAs and ABI3. Further, the efficacy of GABA in alleviating seed dormancy was further confirmed in seeds of pear, apple, and cherry,highlighting its broad applicability across diverse plant species.更多还原

【Abstract】 Seed dormancy release, regulated by abscisic acid(ABA) and gibberellin(GA), is crucial for plant growth and yield. Gamma-aminobutyric acid(GABA) is reported to regulate adaption to stresses in plant. However, its role in seed dormancy release remains elusive. Here, we reported that seed dormancy release was impaired in seeds lacking GABA biosynthesis gene GAD2, while enhanced in seeds deficient in GABA inactivate gene GABA-T, indicating that GABA positively regulated seed dormancy release. Further, ABA was found to antagonize GABA-facilitated seed dormancy release, and GABA failed to alleviate seed dormancy in GA deficiency mutant ga1-t. Analysis of mutants defective in ABA and GA biosynthesis revealed that seed dormancy release, characterized as decreased ABA content and increased GA3content, was suppressed in gad2 while enhanced in gaba-t1-1 mutant. Mechanistically,GABA was shown to promote GA3 biosynthesis by upregulating GA20ox1 expression, while simultaneously repressing ABA biosynthesis by downregulating NCED6 and upregulating CYP707A2 transcription. GABA also amplified GA signaling and inhibited ABA signaling by downregulating genes expression of DELLAs and ABI3. Further, the efficacy of GABA in alleviating seed dormancy was further confirmed in seeds of pear, apple, and cherry,highlighting its broad applicability across diverse plant species.更多还原