State Key Laboratory of Crop Gene Exploitation and Utilization in Southwest China, Wenjiang, Chengdu, 611130, Sichuan, P. R. China.
Triticeae Research Institute, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, P. R. China.
BMC Genomics. 2023 Apr 5;24(1):178. doi: 10.1186/s12864-023-09268-7.
Fusarium crown rot (FCR) is a chronic disease of cereals worldwide. Compared with tetraploid wheat, hexaploid wheat is more resistant to FCR infection. The underlying reasons for the differences are still not clear. In this study, we compared FCR responses of 10 synthetic hexaploid wheats (SHWs) and their tetraploid and diploid parents. We then performed transcriptome analysis to uncover the molecular mechanism of FCR on these SHWs and their parents.
We observed higher levels of FCR resistance in the SHWs compared with their tetraploid parents. The transcriptome analysis suggested that multiple defense pathways responsive to FCR infection were upregulated in the SHWs. Notably, phenylalanine ammonia lyase (PAL) genes, involved in lignin and salicylic acid (SA) biosynthesis, exhibited a higher level of expression to FCR infection in the SHWs. Physiological and biochemical analysis validated that PAL activity and SA and lignin contents of the stem bases were higher in SHWs than in their tetraploid parents.
Overall, these findings imply that improved FCR resistance in SHWs compared with their tetraploid parents is probably related to higher levels of response on PAL-mediated lignin and SA biosynthesis pathways.
镰刀菌顶腐病（FCR）是一种世界性的谷类慢性病。与四倍体小麦相比，六倍体小麦对 FCR 感染的抗性更强。造成这种差异的根本原因尚不清楚。在这项研究中，我们比较了 10 个合成六倍体小麦（SHW）及其四倍体和二倍体亲本对 FCR 的反应。然后，我们进行了转录组分析，以揭示这些 SHW 及其亲本对 FCR 的分子机制。
我们观察到 SHW 对 FCR 的抗性水平高于其四倍体亲本。转录组分析表明，SHW 中多条防御途径对 FCR 感染的反应上调。值得注意的是，苯丙氨酸解氨酶（PAL）基因参与木质素和水杨酸（SA）的生物合成，在 SHW 中对 FCR 感染的表达水平更高。生理生化分析验证了 SHW 中 PAL 活性以及茎基部的 SA 和木质素含量均高于其四倍体亲本。
总的来说，这些发现表明，与四倍体亲本相比，SHW 对 FCR 的抗性增强可能与 PAL 介导的木质素和 SA 生物合成途径的更高水平反应有关。
