Wheat BAX inhibitor-1 contributes to wheat resistance to Puccinia striiformis.
BAX inihibitor-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 BI-1 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 (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.
State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University,  Yangling, Shaanxi 712100, PR China.
Xiaojie
X
Wang
Chunlei
C
Tang
Xueling
X
Huang
Fangfang
F
Li
Xianming
X
Chen
Gang
G
Zhang
Yanfei
Y
Sun
Dejun
D
Han
Zhensheng
Z
Kang
D000595:Amino Acid Sequence; D001487:Basidiomycota / Q000254:growth & development / Q000502:physiology*; D016923:Cell Death; D060467:Disease Resistance; D015870:Gene Expression; D018506:Gene Expression Regulation, Plant / Q000235:genetics; D020868:Gene Silencing; D005838:Genotype; D054884:Host-Pathogen Interactions; D008969:Molecular Sequence Data; D010802:Phylogeny; D035261:Plant Components, Aerial / Q000235:genetics / Q000276:immunology / Q000502:physiology; D010935:Plant Diseases / Q000276:immunology* / Q000382:microbiology; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D018517:Plant Roots / Q000235:genetics / Q000276:immunology / Q000502:physiology; D017434:Protein Structure, Tertiary; D036226:Seedlings / Q000235:genetics / Q000276:immunology / Q000502:physiology; D016415:Sequence Alignment; D014026:Nicotiana / Q000235:genetics / Q000276:immunology / Q000502:physiology; D019076:Transgenes; D014908:Triticum / Q000235:genetics* / Q000276:immunology / Q000382:microbiology / Q000502:physiology
D010940:Plant Proteins