Sugar-mediated regulation of hormone signaling is crucial for optimizing growth under normal conditions and ensuring survival during environmental stress.Previous studies have shown that sugar starvation in-duces the ...Sugar-mediated regulation of hormone signaling is crucial for optimizing growth under normal conditions and ensuring survival during environmental stress.Previous studies have shown that sugar starvation in-duces the degradation of BRASSINAZOLE RESISTANT 1(BZR1),the master transcription factor of the bras-sinosteroid(BR)signaling pathway,thereby inhibiting growth.However,the molecular mechanism linking sugar signaling to BZR1 degradation remains unknown.To identify proteins that mediate starvation-induced BZR1 degradation,we performed a quantitative proteomic analysis of the BZR1 interactome under starvation conditions and identified UBIQUITIN PROTEIN LIGASE 3(UPL3)as a sugar-regulated protein that promotes BZR1 degradation and regulates growth and survival in response to sugar availability.upl3 mu-tants showed increased BZR1 accumulation and larger seedling size compared to the wild type under sugar-limiting conditions,but not when grown on sugar-containing medium,which indicates that UPL3 me-diates BZR1 degradation and growth inhibition under sugar-limited conditions.Although upl3 mutations promoted growth under short-term starvation,they substantially reduced survival under long-term starva-tion.The enhanced growth phenotype of upl3 was also observed when target of rapamycin(TOR)was inactivated,but not when BR biosynthesis was blocked,suggesting that UPL3 acts downstream of sugar-TOR signaling to regulate BZR1 degradation.Furthermore,UPL3 protein levels increased post-transcriptionally in response to starvation and TOR inhibition,and decreased upon sugar treatment.Our study identifies UPL3 as a key molecular link between sugar signaling and BR signaling.We propose that sugar-TOR signaling inhibits UPL3 to promote BZR1 accumulation and growth,thereby optimizing plant growth and survival in response to sugar availability.展开更多
目的：建立简单、快速、同时测定玉米中伏马菌素的超高效液相色谱三重四极杆质谱确证方法。方法：样品经混合溶剂50/50的乙腈/水溶液（V/V）提取,SPE柱净化、离心、吹干、定容和过滤。进样,经超高压液相BEH C18（50 mm×2.1 mm I.D....目的：建立简单、快速、同时测定玉米中伏马菌素的超高效液相色谱三重四极杆质谱确证方法。方法：样品经混合溶剂50/50的乙腈/水溶液（V/V）提取,SPE柱净化、离心、吹干、定容和过滤。进样,经超高压液相BEH C18（50 mm×2.1 mm I.D.,粒径1.7μm）柱分离,选用0.1%甲酸溶液和乙腈/甲醇（50/50,V/V）作为流动相,经梯度洗脱将3种伏马菌毒素完全分离。采用基质加标法定量。结果：经方法学研究验证：在ESI＋电离方式下3种伏马菌毒素的最低定量限LOQ：FB1为3.08μg/kg,FB2为1.00μg/kg,FB3为0.45μg/kg,均低于欧盟、美国的最低限量。相关系数r均大于0.999;低、中、高浓度加标回收率：88.6±6.4%～93.7±4.1%,80.9±2.0%～96.1±6.9%,84.9±1.6%～97.0±2.9%。结论：该方法具有预处理简单、检测速度快、灵敏度高的优点,可适用于玉米样品中伏马菌毒素的确认和准确定量检测,可满足各国对伏马菌毒素的最低检出要求。展开更多
基金supported by grants from the National Institute of General Medical Sciences(R01GM066258 to Z.-Y.W.and S10OD030441 to S.-L.X.)the National Natural Science Foundation of China(31800239,http://www.nsfc.gov.cn)the China Scholarship Council(to Z.Z.).
文摘Sugar-mediated regulation of hormone signaling is crucial for optimizing growth under normal conditions and ensuring survival during environmental stress.Previous studies have shown that sugar starvation in-duces the degradation of BRASSINAZOLE RESISTANT 1(BZR1),the master transcription factor of the bras-sinosteroid(BR)signaling pathway,thereby inhibiting growth.However,the molecular mechanism linking sugar signaling to BZR1 degradation remains unknown.To identify proteins that mediate starvation-induced BZR1 degradation,we performed a quantitative proteomic analysis of the BZR1 interactome under starvation conditions and identified UBIQUITIN PROTEIN LIGASE 3(UPL3)as a sugar-regulated protein that promotes BZR1 degradation and regulates growth and survival in response to sugar availability.upl3 mu-tants showed increased BZR1 accumulation and larger seedling size compared to the wild type under sugar-limiting conditions,but not when grown on sugar-containing medium,which indicates that UPL3 me-diates BZR1 degradation and growth inhibition under sugar-limited conditions.Although upl3 mutations promoted growth under short-term starvation,they substantially reduced survival under long-term starva-tion.The enhanced growth phenotype of upl3 was also observed when target of rapamycin(TOR)was inactivated,but not when BR biosynthesis was blocked,suggesting that UPL3 acts downstream of sugar-TOR signaling to regulate BZR1 degradation.Furthermore,UPL3 protein levels increased post-transcriptionally in response to starvation and TOR inhibition,and decreased upon sugar treatment.Our study identifies UPL3 as a key molecular link between sugar signaling and BR signaling.We propose that sugar-TOR signaling inhibits UPL3 to promote BZR1 accumulation and growth,thereby optimizing plant growth and survival in response to sugar availability.
文摘目的：建立简单、快速、同时测定玉米中伏马菌素的超高效液相色谱三重四极杆质谱确证方法。方法：样品经混合溶剂50/50的乙腈/水溶液（V/V）提取,SPE柱净化、离心、吹干、定容和过滤。进样,经超高压液相BEH C18（50 mm×2.1 mm I.D.,粒径1.7μm）柱分离,选用0.1%甲酸溶液和乙腈/甲醇（50/50,V/V）作为流动相,经梯度洗脱将3种伏马菌毒素完全分离。采用基质加标法定量。结果：经方法学研究验证：在ESI＋电离方式下3种伏马菌毒素的最低定量限LOQ：FB1为3.08μg/kg,FB2为1.00μg/kg,FB3为0.45μg/kg,均低于欧盟、美国的最低限量。相关系数r均大于0.999;低、中、高浓度加标回收率：88.6±6.4%～93.7±4.1%,80.9±2.0%～96.1±6.9%,84.9±1.6%～97.0±2.9%。结论：该方法具有预处理简单、检测速度快、灵敏度高的优点,可适用于玉米样品中伏马菌毒素的确认和准确定量检测,可满足各国对伏马菌毒素的最低检出要求。
