He Feng, Kange Alex-Machio, Yang Jie, Xiao Jiaxin, Wang Rongbo, Yang Lu, Jia Yifan, Fu Zheng Qing, Zhao Yancun, Liu Fengquan
Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, China.
College of Life Sciences, Anhui Normal University, Wuhu, China.
Front Microbiol. 2022 Mar 3;13:784686. doi: 10.3389/fmicb.2022.784686. eCollection 2022.
Pears ( sp.) are widely cultivated in China, and their yield accounts for more than 60% of global pear production. The fungal pathogen is a major causal agent of pear canker disease, which results in enormous losses of pear production in northern China. In this study, we characterized a ZnCys transcription factor that contains one GAL4 domain and a fungal-trans domain, which are present in VpxlnR. The gene expression was upregulated in the invasion stage of . To investigate its functions, we constructed gene deletion mutants and complementary strains. We observed that the growth of the mutants was reduced on potato dextrose agar (PDA), Czapek plus glucose or sucrose compared with that of the wild-type strain. Additionally, mutants exhibited loss of function in fruiting body formation. Moreover, mutants were more susceptible to hydrogen peroxide (HO) and salicylic acid (SA) and were reduced in their virulence at the early infection stage. According to a previous study, VpxlnR-interacting motifs containing NRHKGNCCGM were searched in the genome, and we obtained 354 target genes, of which 148 genes had Clusters of Orthologous Groups (COG) terms. PHI-BLAST was used to identify virulence-related genes, and we found 28 hits. Furthermore, eight genes from the 28 PHI-BLAST hits were further assessed by yeast one-hybrid (Y1H) assays, and five target genes, salicylate hydroxylase (VP1G_09520), serine/threonine-protein kinase (VP1G_03128), alpha-xylosidase (VP1G_06369), G-protein beta subunit (VP1G_02856), and acid phosphatase (VP1G_03782), could interact with VpxlnR . Their transcript levels were reduced in one or two mutants. Taken together, these findings imply that VpxlnR is a key regulator of growth, development, stress, and virulence through controlling genes involved in signaling pathways and extracellular enzyme activities in . The motifs interacting with VpxlnR also provide new insights into the molecular mechanism of xlnR proteins.
梨（品种未提及）在中国广泛种植，其产量占全球梨总产量的60%以上。这种真菌病原体是梨溃疡病的主要致病因子，在中国北方导致梨产量的巨大损失。在本研究中，我们鉴定了一个锌指转录因子，它含有一个GAL4结构域和一个真菌转运结构域，这些结构域存在于VpxlnR中。该基因在[病原体名称未明确]的侵染阶段表达上调。为了研究其功能，我们构建了基因缺失突变体和互补菌株。我们观察到，与野生型菌株相比，[病原体名称未明确]突变体在马铃薯葡萄糖琼脂（PDA）、察氏培养基加葡萄糖或蔗糖上的生长受到抑制。此外，[病原体名称未明确]突变体在子实体形成方面表现出功能丧失。而且，[病原体名称未明确]突变体对过氧化氢（H₂O₂）和水杨酸（SA）更敏感，并且在早期感染阶段毒力降低。根据先前的一项研究，在[病原体名称未明确]基因组中搜索了包含NRHKGNCCGM的VpxlnR相互作用基序，我们获得了354个靶基因，其中148个基因具有直系同源簇（COG）术语。使用PHI-BLAST来鉴定毒力相关基因，我们发现了28个命中结果。此外，通过酵母单杂交（Y1H）试验对这28个PHI-BLAST命中结果中的8个基因进行了进一步评估，5个靶基因，即水杨酸羟化酶（VP1G_09520）、丝氨酸/苏氨酸蛋白激酶（VP1G_03128）、α-木糖苷酶（VP1G_06369）、G蛋白β亚基（VP1G_02856）和酸性磷酸酶（VP1G_03782），可以与VpxlnR相互作用。它们的转录水平在一两个[病原体名称未明确]突变体中降低。综上所述，这些发现表明VpxlnR通过控制参与[病原体名称未明确]信号通路和细胞外酶活性的基因，是生长、发育、应激和毒力的关键调节因子。与VpxlnR相互作用的基序也为xlnR蛋白的分子机制提供了新的见解。
