Drought stress is a crucial environmental factor that limits plant growth,development,and productivity.Autophagy of misfolded proteins can help alleviate the damage caused in plants experiencing drought.However,the me...Drought stress is a crucial environmental factor that limits plant growth,development,and productivity.Autophagy of misfolded proteins can help alleviate the damage caused in plants experiencing drought.However,the mechanism of autophagy-mediated drought tolerance in plants remains largely unknown.Here,we cloned the gene for a maize(Zea mays)selective autophagy receptor,NEXT TO BRCA1GENE 1(ZmNBR1),and identified its role in the response to drought stress.We observed that drought stress increased the accumulation of autophagosomes.RNA sequencing and reverse transcriptionquantitative polymerase chain reaction showed that ZmNBR1 is markedly induced by drought stress.ZmNBR1 overexpression enhanced drought tolerance,while its knockdown reduced drought tolerance in maize.Our results established that ZmNBR1 mediates the increase in autophagosomes and autophagic activity under drought stress.ZmNBR1 also affects the expression of genes related to autophagy under drought stress.Moreover,we determined that BRASSINOSTEROID INSENSITIVE1A(ZmBRI1a),a brassinosteroid receptor of the BRI1-like family,interacts with ZmNBR1.Phenotype analysis showed that ZmBRI1a negatively regulates drought tolerance in maize,and genetic analysis indicated that ZmNBR1 acts upstream of ZmBRI1a in regulating drought tolerance.Furthermore,ZmNBR1facilitates the autophagic degradation of ZmBRI1a under drought stress.Taken together,our results reveal that ZmNBR1 regulates the expression of autophagy-related genes,thereby increasing autophagic activity and promoting the autophagic degradation of ZmBRI1a under drought stress,thus enhancing drought tolerance in maize.These findings provide new insights into the autophagy degradation of brassinosteroid signaling components by the autophagy receptor NBR1 under drought stress.展开更多
基金supported by National Natural Science Foundation of China(32201707)Natural Science Foundation of Jiangsu Province(BK20220999)+5 种基金the Fundamental Research Funds for the Central Universities(KYQN2023025)China Postdoctoral Science Foundation(2021M701739,2023T160323)Jiangsu Funding Program for Excellent Postdoctoral Talent(2022ZB330)Open Competition Mechanism to Select the Best Candidates Fund of Jiangsu Province(JBGS[2021]012)Key Research and Development Program of Ningxia Hui Autonomous Region(2023BCF01009)the Achievement Transformation Fund Project of Hainan Research Institute of Nanjing Agricultural University(NAUSYCG-YB07)。
文摘Drought stress is a crucial environmental factor that limits plant growth,development,and productivity.Autophagy of misfolded proteins can help alleviate the damage caused in plants experiencing drought.However,the mechanism of autophagy-mediated drought tolerance in plants remains largely unknown.Here,we cloned the gene for a maize(Zea mays)selective autophagy receptor,NEXT TO BRCA1GENE 1(ZmNBR1),and identified its role in the response to drought stress.We observed that drought stress increased the accumulation of autophagosomes.RNA sequencing and reverse transcriptionquantitative polymerase chain reaction showed that ZmNBR1 is markedly induced by drought stress.ZmNBR1 overexpression enhanced drought tolerance,while its knockdown reduced drought tolerance in maize.Our results established that ZmNBR1 mediates the increase in autophagosomes and autophagic activity under drought stress.ZmNBR1 also affects the expression of genes related to autophagy under drought stress.Moreover,we determined that BRASSINOSTEROID INSENSITIVE1A(ZmBRI1a),a brassinosteroid receptor of the BRI1-like family,interacts with ZmNBR1.Phenotype analysis showed that ZmBRI1a negatively regulates drought tolerance in maize,and genetic analysis indicated that ZmNBR1 acts upstream of ZmBRI1a in regulating drought tolerance.Furthermore,ZmNBR1facilitates the autophagic degradation of ZmBRI1a under drought stress.Taken together,our results reveal that ZmNBR1 regulates the expression of autophagy-related genes,thereby increasing autophagic activity and promoting the autophagic degradation of ZmBRI1a under drought stress,thus enhancing drought tolerance in maize.These findings provide new insights into the autophagy degradation of brassinosteroid signaling components by the autophagy receptor NBR1 under drought stress.
