Effects of hormones and sucrose on the germination and growth of lateral buds of tomato cotyledon nodes
[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.
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万方数据
维普
