Characterization of NtD14 by Overexpression in Nicotiana tabacum L.

Key words: 
• Strigolactone /
• NtD14 /
• tobacco /
• genetic transformation

Abstract: D14 is a key gene for strigolactone signaling. To study the function of the tobacco D14 gene（NtD14）,we cloned theNtD14 gene by homologous cloning. A p CAMBIA1302-Nt D14 plant overexpression vector was constructed and transformed into Nicotiana tabacum L. by Agrobacterium-mediated leaf disk transformation. The transgenic tobacco plant with overexpressingNtD14 gene had a lower plant height than the wild type,and their leaves became shorter and smaller,but there was no significant difference in leaf aspect ratio.The number of branches of the transgenic lines decreased. ELISA analysis showed that the auxin content of all the overexpressedNtD14 transgenic lines was lower than that of the wild type,indicating that the plant height and leaf size of theNtD14 gene transformed tobacco plants may be related to the decrease of auxin content in the transgenic plants. In addition,the malondialdehyde（ MDA） content and the catalase（ CAT） activity were significantly higher in the transgenic lines than in the wild type. The peroxidase（ POD） activity of the transgenic lines was significantly lower than that of the wild type,and the contents of CAT and POD were inversely proportional,but there was no significant difference in the content of superoxide dismutase（ SOD）,indicating that overexpression of NtD14 gene affected Redox reaction in the transgenic tobacco plants.