Proteins containing the toll/interleukin-1 receptor (TIR) domain are critical components of the plant immune system. However, the TIR gene family in wheat and its wild relative Thinopyrum species remains poorly characterized. In this study, we systematically identified the TIR genes in common wheat, Thinopyrum elongatum, Thinopyrum intermedium, and Thinopyrum ponticum by using genome and RNA-seq data, and further analyzed their evolutionary relationships and expression patterns. The results showed that TIR genes in common wheat, Th.elongatum, and Th.intermedium are highly conserved in both number and structure, with each subgenome containing four members (TIR1, TNP1, TNP2, and TNP3). In contrast, a significant expansion of TIR genes occurred in Th. ponticum, where 54 TIR genes were identified; the greatest expansion was observed in the TpTIR1 clade. Expression profiling showed that TNP1 genes are highly and constitutively expressed across various tissues, suggesting their involvement in plant growth and development. Conversely, TIR1 genes were barely expressed under infection of powdery mildew and stripe rust, but were strongly induced by Fusarium graminearum inoculation. Collectively, our findings reveal the constitution and evolutionary characteristics of TIR genes in wheat and Thinopyrum species, and provide a foundation for investigating the functional divergence of this gene family.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |