园艺学报 ›› 2021, Vol. 48 ›› Issue (12): 2385-2402.doi: 10.16420/j.issn.0513-353x.2020-1063

• 研究论文 • 上一篇    下一篇


张静亚, 雷蕾, 尚庆茂, 谢露露, 董春娟()   

  1. 中国农业科学院蔬菜花卉研究所,农业农村部园艺作物生物学与种质创制重点实验室,北京 100081
  • 收稿日期:2021-04-19 修回日期:2021-07-21 发布日期:2022-01-04
  • 通讯作者: 董春娟
  • 基金资助:

Expression Patterns of Tomato SlIAMT1 and SlIAMT2 and Their Functions During Hypocotyl and Root Development

ZHANG Jingya, LEI Lei, SHANG Qingmao, XIE Lulu, DONG Chunjuan()   

  1. Key Laboratory of Biology and Genetic Improvement of Horticultural Crops,Ministry of Agriculture and Rural Affairs,Institute of Vegetables and Flowers,Chinese Academy of Agricultural Sciences,Beijing 100081,China
  • Received:2021-04-19 Revised:2021-07-21 Published:2022-01-04
  • Contact: DONG Chunjuan


从‘Ailsa Craig’番茄中克隆到两个IAA甲基转移酶(indole-3-acetic acid methyltransferase,IAMT)基因SlIAMT1SlIAMT2,其全长分别为2 510和4 620 bp,均编码390个氨基酸。序列分析表明,二者均具有IAA甲基转移酶特异的底物结合位点和催化位点,与拟南芥AtIAMT1的序列相似度高于70%。利用PlantCARE数据库进行启动子顺式作用元件预测分析发现,SlIAMT1SlIAMT2启动子序列中含有与生长素(IAA)、脱落酸(ABA)、水杨酸(SA)及光信号响应相关的顺式作用元件。荧光定量PCR分析表明,SlIAMT1在番茄萌发的种子、幼苗根、新叶以及青果中有优势表达,而SlIAMT2则主要在花蕾中表达。诱导表达分析表明,番茄幼苗中,尤其是下胚轴中,SlIAMT1的表达受强光照(150 μmol · m-2 · s-1)强烈诱导,而SlIAMT2受光照诱导程度较低;15 ℃低温处理对SlIAMT1SlIAMT2的诱导程度均较低;IAA处理可显著诱导SlIAMT1SlIAMT2的表达;ABA诱导根和下胚轴中SlIAMT1的表达,但抑制子叶中的SlIAMT1的表达,并抑制根中SlIAMT2的表达;SA抑制根和子叶中SlIAMT1的表达,但对子叶中SlIAMT2的表达有一定的诱导作用。异源转化结果显示,拟南芥iamt1缺失突变体下胚轴和主根长于野生型,突变体中过量表达SlIAMT1可有效恢复下胚轴和主根的表型;进一步分析表明,SlIAMT1过量表达显著降低了拟南芥幼苗侧根对IAA的敏感性。试验结果表明,SlIAMT响应光和激素信号,通过IAA甲基化修饰调节IAA稳态,调控幼苗下胚轴和根系发育。

关键词: 番茄, IAA甲基转移酶, 表达分析, 根系, 下胚轴


Two indole-3-acetic acid methyltransferase(IAMT)genes,SlIAMT1 and SlIAMT2,were cloned from tomato cultivar‘Ailsa Craig’. The full-length of SlIAMT1 and SlIAMT2 genes were 2 510 and 4 620 bp,respectively,and both of them encode 390 amino acids. The sequence alignment suggested that both SlIAMT1 and SlIAMT2 contained all of the substrate binding sites and catalytic sites for IAMT,and showed more than 70% sequence identity with AtIAMT1 from Arabidopsis. In silico analysis suggested that the promoter sequences of SlIAMT1 and SlIAMT2 contained several typical cis-acting elements,including auxin-,abscisic acid-,salicylic acid- and light-responsive elements by using PlantCARE databases. Real-time PCR assays showed that SlIAMT1 was highly expressed in the germinating seeds,roots of 5-d-old seedlings,young leaves and green fruits,while SlIAMT2 was extensively expressed in the flower buds. In tomato seedlings,the expression of SlIAMT1 was remarkably induced by high light intensity(150 μmol · m-2 · s-1),especially in the hypocotyls. However,the inducible level of SlIAMT2 was much lower. The induction of SlIAMT1 and SlIAMT2 was low by low temperature(15 ℃)treatment. IAA also exerted inducible effects on SlIAMT1 and SlIAMT2 expression. ABA induced the expression of SlIAMT1 in root and hypocotyl,but repressed its expression in cotyledons,while for SlIAMT2,its expression was repressed by ABA in root. SA repressed the expression of SlIAMT1 in roots and cotyledons,but slightly induced SlIAMT2 expression in cotyledons. The function of SlIAMT1 gene was further investigated by Agrobacterium-mediated genetic transformation into Arabidopsis. The iamt1 mutant showed longer hypocotyl and primary roots than wild type,and these phenotypes of mutant were functionally complemented by overexpression of SlIAMT1. Overexpression of SlIAMT1 could also reduce the sensitivity to IAA in lateral roots. These results indicated that SlIAMT genes respond to light and hormone signals,and regulate the IAA homeostasis via methylation and thereby regulate the hypocotyl and root development.

Key words: Solanum lycopersicum, IAMT, expression analysis, root, hypocotyl