Mormile Brendan W, Yan Yan, Bauer Taran, Wang Li, Rivero Rachel C, Carpenter Sara C D, Danmaigona Clement Catherine, Cox Kevin L, Zhang Lin, Ma Xiyu, Wheeler Terry A, Dever Jane K, He Ping, Bogdanove Adam J, Shan Libo
Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, 48109, USA.
Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX, 77843, USA.
Nat Commun. 2025 Jan 14;16(1):644. doi: 10.1038/s41467-025-55926-7.
Bacterial transcription activator-like effectors (TALEs) promote pathogenicity by activating host susceptibility (S) genes. To understand the pathogenicity and host adaptation of Xanthomonas citri pv. malvacearum (Xcm), we assemble the genome and the TALE repertoire of three recent Xcm Texas isolates. A newly evolved TALE, Tal7b, activates GhSWEET14a and GhSWEET14b, different from GhSWEET10 targeted by a TALE in an early Xcm isolate. Activation of GhSWEET14a and GhSWEET14b results in water-soaked lesions. Transcriptome profiling coupled with TALE-binding element prediction identify a pectin lyase gene as an additional Tal7b target, quantitatively contributing to Xcm virulence alongside GhSWEET14a/b. CRISPR-Cas9 gene editing supports the function of GhSWEETs in cotton bacterial blight and the promise of disrupting the TALE-binding site in S genes for disease management. Collectively, our findings elucidate the rapid evolution of TALEs in Xanthomonas field isolates and highlight the virulence mechanism wherein TALEs induce multiple S genes to promote pathogenicity.
细菌转录激活样效应因子（TALEs）通过激活宿主感病（S）基因来促进致病性。为了解柑桔黄单胞菌锦葵致病变种（Xcm）的致病性和宿主适应性，我们组装了三个近期来自德克萨斯州的Xcm分离株的基因组和TALE文库。一个新进化出的TALE，Tal7b，激活了GhSWEET14a和GhSWEET14b，这与早期Xcm分离株中一个TALE靶向的GhSWEET10不同。GhSWEET14a和GhSWEET14b的激活导致水渍状病斑。转录组分析结合TALE结合元件预测确定了一个果胶裂解酶基因是Tal7b的另一个靶标，与GhSWEET14a/b一起对Xcm的毒力有定量贡献。CRISPR-Cas9基因编辑支持了GhSWEETs在棉花细菌性叶枯病中的功能，以及破坏S基因中TALE结合位点用于病害管理的前景。总的来说，我们的研究结果阐明了Xanthomonas田间分离株中TALEs的快速进化，并突出了TALEs诱导多个S基因以促进致病性的毒力机制。
