Download Genetic Engineering of Late Blight Resistance in Potato

Genetic Engineering of Late Blight Resistance in Potato
Sanwen Huang, Dongyu Qu, Jianfei Xu, Zhiqi Jia, Cuihua Xin, Ying Li, Zhonghua Zhang
The oomycete pathogen Phytophthora infestans causes late blight, a devastating disease of
potato. Resistance breeding was not successful in release of cultivars with durable protection,
which is largely due to the extremely high evolutionary potential of the pathogen. Recent
studies in molecular interaction of the pathosystem have results in isolation of several
resistance genes from potato and several avirulence genes from P. infestans. This new
development paves new ways to combat the disease
In our lab, we are working on two approaches to exploit the cloned genes. First, an R-gene
polyculture will be generated and tested in potato field. The polyculture aims to ensure a
resistance polymorphism in the field to enable a more durable protection than conventional
monoculture that deploy genetically uniform cultivar. Several genes are transforming into
major cultivars in China. We are also in the way to clone a few more R genes. A new binary
vector is made and tested for marker-free transformation. To release R gene polyculture
accordingly, we are surveying the population structure of P. infestans in major production
zones using the known sequences of the avirulence genes. The ongoing genomic projects for
both the host and the pathogen will ultimately render a polyculture with R genes tailored the
Avr gene makeup of the target population.
Second, a versatile positive-mutation system is being made to uncover genes in perceiving of
pathogen signals and in initiating defense reaction. A tomato plant with the interacting pair
R3a-Avr3a, with Avr3a under control by chemical-inducible promotor. Spray with the chemical
can identify M2 families in which a signaling gene is defected. Such a gene could be
manipulated to convey broad-spectrum resistance.
Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, No. 12 Zhong Guan Cun Nan Da
Jie, Beijing, 100081, China
Presenting author: Sanwen Huang ([email protected]; Fax: +86-10-62174123)