番茄SlSIP1L12基因负调控种子萌发的研究

Correlation between SlSIP1L12 Expression and Seed Germination of Tomato Plants

【目的】鉴定番茄中Trihelix转录因子SIP1亚家族SlSIP1L12基因的生物功能,【方法】利用RT-PCR分析了SlSIP1L12基因的表达模式、对外源激素和非生物胁迫的响应;利用RNAi干扰技术获得了SlSIP1L12转基因植株,利用ELISA鉴定转基因种子体内ABA的含量。【结果】(1)基因克隆分析表明:番茄AC++中,SlSIP1L12基因编码长度为1125bp,编码374个氨基酸;进化分析表明,番茄SlSIP1L12基因进化明显。(2)表达模式证实:SlSIP1L12基因主要在茎、成熟叶中表达,花和果实中次之。(3)外源处理显示:SlSIP1L12受外源激素ABA和脱水胁迫诱导,说明SlSIP1L12功能与ABA有关。(4)SlSIP1L12转基因株系的种子发芽速度快于对照;相同条件下,胚根伸长速度明显比对照快。(5)发芽7 d时,转基因种子体内ABA含量明显小于对照。【结论】SlSIP1L12基因负调控番茄种子萌发的机制与ABA含量密切相关。

【Objective】Role of SlSIP1L12,an SIP1 subfamily gene of trihelix transcription factors,played in tomato seed germination was investigated.【Method】Expressions under and responses to phytohormone and abiotic stress of SlSIP1L12 were tested by RT-PCR.The RNAi technology was used to suppress the SlSIP1L12 expression to reveal its function on the seed germination.ELISA was applied to detect the endogenous ABA contents in the seeds.【Result】(1)The length of SlSIP1L12 was 1125bp in AC++that encoded 374 amino acids.The phylogenetic analysis confirmed that SIP1 genes had indeed evolved in AC++.(2)SlSIP1L12 was primarily expressed in the stems and mature leaves,and secondly,in the flowers and fruits.(3)The suppressed expression of SlSIP1L12 could be artificially induced by ABA or dehydration,which implied a close relationship between the gene and ABA.(4)The germination of the SlSIP1L12 transgenic seeds was faster and grew to longer radicles than control.(5)ABA contents were significantly reduced in the transgenic seeds 7d after germination.【Conclusion】The downregulated SlSIP1L12 that stimulated germination of tomato seeds was postulated to be closely associated with the ABA response of the plant.