首页|毛白杨半胱氨酸蛋白酶PtoCP1基因参与植物激素调控的叶片衰老

毛白杨半胱氨酸蛋白酶PtoCP1基因参与植物激素调控的叶片衰老

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半胱氨酸蛋白酶在植物不同组织中的特异性表达发挥了多种功能.本文探究了毛白杨半胱氨酸蛋白酶PtoCP1基因在激素诱导下参与叶片衰老的机制.使用脱落酸(ABA)、茉莉酸甲酯(MeJA)、乙烯(ACC)对杨树叶片进行处理,不同时间段后观察叶片表型、检测叶绿素含量以及PtoCP1基因相对表达量,发现激素诱导后的叶片黄化加速,叶绿素含量下降,同时PtoCP1表达量上调,而ptocp1突变体则延缓了叶片的衰老.进一步对PtoCP1启动子元件分析发现,其含有ABA、MeJA响应元件,因此以相应的ABA、MeJA激素分别处理含ProPtoCP1-GUS-pBI121重组载体的转基因拟南芥幼苗,并观察GUS染色差异和检测报告基因GUS的相对表达量.结果显示,ABA诱导下GUS染色加深,GUS表达量上升.综上所述,PtoCP1启动子可以通过响应ABA调控基因的表达,从而使植物对外界胁迫作出反应,引起叶片衰老,该研究为进一步理解激素诱导植物半胱氨酸蛋白酶参与叶片衰老的机制提供了理论支持.
Involvement of cysteine protease PtoCP1 gene in plant hormone-regulated leaf senescence in Populus tomentosa
Cysteine proteases,an important family of proteases,are expressed in different plant tissues and have various functions.This study explored the mechanism underlying the involvement of the cysteine protease PtoCP1 gene in leaf senescence of Populus tomentosa under hormone induction.Initially,poplar leaves were treated with abscisic acid(ABA),methyl jasmonate(Me J A),and ethylene(ACC)for 0,6 and 12 h,and 1,2,or 3 d to observe leaf phenotypes,assess chlorophyll content,and measure relative expression of the PtoCP1 gene.The results demonstrated that hormone-induced leaf yellowing was accelerated compared with the control group;the most significant leaf yellowing was observed under ABA treatment,followed by MeJA and ACC treatments.Chlorophyll content was significantly lower in leaves treated with ABA for 3 d compared with the control group;there was no significant difference in chlorophyll content between MeJA and ACC treatments.Furthermore,expression of the PtoCP1 gene was significantly increased at 6 h,12 h,and 3 d after induction with ABA and MeJA;induction with ACC led to a significant increase in PtoCP1 gene expression at 12 h.Therefore,treatment with exogenous hormones(e.g.,ABA,MeJA,and ACC)directly or indirectly regulates the transcription of PtoCP1,indicating its involvement in the induction of plant leaf senescence by exogenous hormones.Next,ptocp1 mutant leaves of P.tomentosa were treated with the same concentrations of hormones.The results demonstrated that the ptocp1 mutant exhibited delayed leaf senescence compared with the wild type,indicating that PtoCP1 can directly or indirectly respond to ABA,MeJA,or ACC induction and participate in leaf senescence in P.tomentosa.Further analysis of PtoCP1 promoter elements revealed the presence of both MeJA response elements and a large number of ABA response elements.Therefore,transgenic Arabidopsis seedlings containing ProPtoCP1-GUS-PBI121 recombinant vector were treated with the corresponding ABA and MeJA hormones.Subsequently,GUS histochemical staining and analysis of the relative expression of the reporter gene GUS were performed to determine whether the promoter had been induced.ABA treatment led to partial enhancement of GUS staining in Arabidopsis,but no significant effect was observed with MeJA treatment.Additionally,ABA treatment led to a significant increase in GUS expression,whereas MeJA treatment did not lead to a significant increase in GUS expression;thus,ABA is directly involved in PtoCP1 gene expression.In conclusion,the PtoCP1 promoter can regulate PtoCP1 gene expression in response to ABA,enabling plants to respond to external stress and initiate leaf senescence.This study enhances the overall understanding of the mechanism by which plant cysteine proteases regulate hormone-induced leaf senescence.

PtoCP1 genepromoterhormone treatmentfunctional analysis

国洪丽、陈梦圆、范雅为、刘涵、孙蕾倩、刘迪、李慧、王馨、陆海

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北京林业大学生物科学与技术学院,林木遗传育种全国重点实验室,树木花卉育种生物工程国家林业和草原局重点实验室,北京 100083

PtoCP1基因 启动子 激素诱导 功能分析

国家自然科学基金国家重点研发计划

319716182021YFD2200101

2024

科学通报
中国科学院国家自然科学基金委员会

科学通报

CSTPCD北大核心
影响因子:1.269
ISSN:0023-074X
年,卷(期):2024.69(3)
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