Establishment of a transient expression system in citrus via agro-infiltration

Genetic transformation is a traditional tool for both functional genomics and molecular breeding in plants, but it is time-consuming and low efficient in citrus due to its low transformation rate. It is essential to establish a transient expression system to speed-up gene function identification. Here we report a gene transient expression by using agro-infiltration for citrus. A full comparison was performed between different parameters including Agrobacterium injection buffer solutions, expression vectors and concentrations of the bacterial solution. Results showed that in the transient expression system with injection buffer solution composed of 50mM MES pH5.6, 10mM MgCl2, 150μM acetosyringone, pCAMBIA-2301 expression vector and OD600 = 0.4 as ideal concentration of bacterial solution, a foreign gene could be effectively expressed in citrus. With this system, it is possible to analyze gene function in citrus rapidly.