Page Banner

United States Department of Agriculture

Agricultural Research Service

Research Project: Improved Control of Stripe Rust in Cereal Crops

Location: Wheat Genetics, Quality Physiology and Disease Research

Title: Wheat BAX inhibitor-1 contributes to wheat resistance to Puccinia striiformis

Authors
item Wang, Xiaojie -
item Tang, Chunlei -
item Huang, Xueling -
item Li, Fangfang -
item Chen, Xianming
item Zhang, Gang -
item Sun, Yanfei -
item Han, Dejun -
item Kang, Zhensheng -

Submitted to: Journal of Experimental Botany
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 20, 2012
Publication Date: June 13, 2012
Citation: Wang, X., Tang, C., Huang, X., Li, F., Chen, X., Zhang, G., Sun, Y., Han, D., Kang, Z. 2012. Wheat BAX inhibitor-1 contributes to wheat resistance to Puccinia striiformis. Journal of Experimental Botany. 63:4571-4584. Available: http://jxb.oxfordjournals.org/.

Interpretive Summary: BAX inhibitor-1 (BI-1) is proposed to be a cell death suppressor conserved in both animals and plants. The ability of BI-1 genes to inhibit programmed cell death (PCD) has been well studied in animals, but the physiological importance of BI-1 in plant-microbe interactions remains unclear. This study characterized a BI-1 gene from wheat infected by the wheat stripe rust pathogen. The deduced TaBI-1 protein contained a Bax inhibitor domain and seven transmembrane regions conserved among members of the BI-1 family. Transcription of the wheat gene was detected in all wheat tissues tested, e.g., culms, roots, leaves, anthers and spikelets. The wheat gene exhibited positive transcriptional responses to stripe rust infection and abiotic stresses. Overexpression of the wheat gene in tobacco blocked Bax-induced cell death. Silencing the gene in plants of a resistant wheat genotype converted a resistant reaction to a relatively susceptible reaction when inoculated with an avirulent pathotype of the stripe rust pathogen, and increased the area per infection site, but the percentage of necrotic cells did not change significantly, indicating that the wheat gene is a negative cell death regulator and contributes to wheat resistance to stripe rust. These results provide a better understanding of the molecular mechanism of wheat resistance to stripe rust.

Technical Abstract: BAX inhibitor-1 (BI-1) is proposed to be a cell death suppressor conserved in both animals and plants. The ability of BI-1 genes to inhibit programmed cell death (PCD) has been well studied in animals, but the physiological importance of BI-1 in plant-microbe interactions remains unclear. This study characterized a BI-1 gene from wheat infected by Puccinia striiformis f. sp. tritici (Pst). The deduced TaBI-1 protein contained a Bax inhibitor domain and seven transmembrane regions conserved among members of the BI-1 family. Transcription of TaBI-1 was detected in all wheat tissues tested, e.g., culms, roots, leaves, anthers and spikelets. Furthermore, TaBI-1 exhibited positive transcriptional responses to Pst infection and abiotic stresses. Overexpression of TaBI-1 in tobacco blocked Bax-induced cell death. Silencing TaBI-1 in plants of a resistant wheat genotype converted a resistant reaction to a relatively susceptible reaction when inoculated with an avirulent pathotype of the pathogen, and increased the area per infection site, but the percentage of necrotic cells did not change significantly, indicating that TaBI-1, a negative cell death regulator, contributes to wheat resistance to stripe rust. These results provide a better understanding of the molecular mechanism of wheat resistance to stripe rust.

Last Modified: 10/23/2014
Footer Content Back to Top of Page