[目的]研究激素和蔗糖对番茄子叶节位侧芽萌发和生长的影响,为培育番茄接穗双头苗提供理论依据.[方法]以子叶节位易萌发侧芽番茄TZ1502和不易萌发侧芽番茄TR1525为材料,通过比较打顶后内源激素含量、相关基因表达量变化,以及外源激素和蔗糖喷施对子叶节位侧芽萌发生长的影响,从激素水平和基因表达的角度探讨番茄子叶节位侧芽萌发的调控机理.[结果]打顶后2种番茄的IAA含量和生长素转运基因PIN1的相对表达量均先降低后增加,PIN1的相对表达量在TZ1502中高于TR1525;细胞分裂素合成基因IPT2的相对表达量在TZ1502打顶第3 d增加到最大值,而在TR1525中的相对表达量无显著变化(P>0.05);芽内负调控因子BRC1在TR1525中的相对表达量增加,且高于在TZ1502中的相对表达量.TZ1502侧芽萌发能力强于TR1525,表明打顶后侧芽萌发与IAA和CKs含量及其相关基因的表达有关,同时也与BRC1基因的表达有关.GR24和NAA通过下调IAA3和PIN1基因的表达降低IAA含量,下调IPT2和IPT3基因的表达降低CKs含量,以及上调BRC1基因表达;TIBA通过抑制PIN1基因的表达、上调BRC1基因表达,进而抑制侧芽萌发和生长.相反,蔗糖通过上调PIN1、IAA3、IPT2和IPT3基因的表达增加IAA和CKs的含量,抑制BRC1基因的表达,进而促进子叶节位侧芽萌发和生长.[结论]打顶后番茄TZ1502的子叶节位侧芽萌发能力比TR1525强.番茄子叶节位侧芽萌发与其基因型和激素相关,即IAA3和PIN1基因表达上调且IAA和CKs含量增加、BRC1基因表达下调促进侧芽萌发.培育番茄接穗双头苗,蔗糖外源处理促进子叶节位侧芽萌发和生长,调控作用与CKs的积累效应有关.
[Objective]The purpose of the study was to study the effects of hormones and sucrose on the germination and growth of lateral buds at the node of tomato cotyledons,and to provide theoretical basis for cultivating tomato scion double headed seedlings.[Method]Using tomato TZ1502 which was easy to germinate lateral buds at cotyledon nodes and tomato TR1525 which was not easy to germinate lateral buds as materials,the changes in endogenous hormone con-tent and related gene expression after topping,as well as the effects of exogenous hormones and sucrose spraying on the germination and growth of cotyledon node lateral buds were compared.The regulatory mechanism of tomato cotyledon node lateral bud germination was explored from the perspectives of hormone level and gene expression.[Result]After top-ping,the IAA content and the relative expression of the auxin transport gene PIN1 in the two tomato varieties first de-creased and then increased,with PIN1 relative expression higher in TZ1502 than in TR1525.The relative expression of the cytokinin synthesis gene IPT2 increased to its maximum on the 3rd d of TZ1502 topping,while there was no signifi-cant change in the relative expression of TR1525(P>0.05).The relative expression of the negative regulatory factor BRC1 in the bud increased in TR1525 and was higher than that in TZ1502.TZ1502 had stronger lateral bud germination ability than TR1525,indicating that lateral bud germination after topping was related to the relative expression of IAA and CKs contents and related genes,as well as the expression of BRC1.GR24 and NAA reduced IAA content by down-regulating the expression of IAA3 and PIN1 gene,reduced CKs content by down-regulating the expression of IPT2 and IPT3 gene,and up-regulated BRC1 gene expression.TIBA inhibited lateral bud germination and growth by inhibiting PIN1 expression and up-regulating BRC1 gene expression.On the contrary,sucrose increased the contents of IAA and CKs by up-regulating the expression of PIN1,IAA3,IPT2,and IPT3 gene,inhibited the expression of BRC1 gene,and promoted the germination and growth of cotyledon node lateral buds.[Conclusion]After topping,the lateral bud germination ability of tomato TZ1502 at cotyledon nodes is stronger than that of TR1525.The lateral bud germination of tomato cotyledon nodes is related to their genotypes and hormones,namely,the up-regulation of IAA3 and PIN1 gene expression and the in-crease of IAA and CKs contents,and the down-regulation of BRC1 gene expression to promote lateral bud germination.To cultivate tomato scion double headed seedlings,exogenous treatment can be used to promote the germination and growth of lateral buds at cotyledon nodes,the regulation effect was related to the accumulation effect of CKs.
吴元彩;王东登;郑旭阳;李永强;王鹏;钟川;于文进
广西大学农学院,广西南宁 530004
园艺学与植物营养学
番茄;子叶节位;侧芽;植物激素;蔗糖
tomatoes;cotyledon nodes;lateral buds;plant hormones;sucrose
《南方农业学报》 2024 (002)
509-519 / 11
国家自然科学基金项目(31660568);广西科技重大专项(桂科AA17204039-2,桂科AA17204026-1) National Natural Science Foundation of China(31660568);Guangxi Science and Technology Major Special Project(Guike AA17204039-2,Guike AA17204026-1)
10.3969/j.issn.2095-1191.2024.02.021
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