Differential Gene and Protein Expression in Soybean at Early Stages of Incompatible Interaction with Phytophthora sojae

Soybean root and stem rot caused by Phytophthora sojae is a destructive disease worldwide. Using genetic resistance is an important and major component in the integrated pest management of this disease. To understand molecular mechanisms of root and stem rot resistance in soybeans, the gene and protein expression in hypocotyls and stems of variety Suinong 10 carrying resistance genes Rps1a and Rps2 was investigated by using mRNA differential display reverse transcription PCR and two-dimensional electrophoresis at 0, 0.5, 1, 2, and 4 h after inoculation with P. sojae race 1. The results of the comparison of gene and protein expression showed that at least eight differential fragments at the transcriptional level were related to metabolic pathway, phytoalexin, and signal transduction in defense responses. Sequence analyses indicated that these fragments represented cinnamic acid 4-hydroxylase gene, ATP b gene coding ATP synthase b subunit and ubiquitin-conjugating enzyme gene which upregulated at 0.5 h post inoculation, blue copper protein gene and UDP-N-acetyl-a-D-galactosamine gene which upregulated at 2 h post inoculation, TGA-type basic leucine zipper protein TGA1.1 gene, cyclophilin gene, and 14-3-3 protein gene which upregulated at 4 h post inoculation. Three resistance-related proteins, a-subunit and b-subunit of ATP synthase, and cytochrome P450-like protein, were upregulated at 2 h post inoculation. The results suggested that resistance-related multiple proteins and genes were expressed in the recognition between soybean and P. sojae during zoospore germination, penetration and mycelium growth of P. sojae in soybean.

Differential Responses of Phytophthora sojae to Seed Exudates of Host Soybean and Non-host Maize

In order to clarify the differential response of Phytophthora sojae to the seed exudates of host soybean and non-host maize and understand the relationship between seed exudates and host selectivity of Phytophthora sojae, non-host maize Suiyu 23 and susceptible host soybean Sloan seed exudates were collected to measure their influence on mycelial growth, formation and germination of oospores, chemotaxis, encystment and germination of zoospores of Phytophthora sojae. The results showed that nonhost maize seed exudates exhibited repellency to zoospores of Phytophthora sojae, it also could significantly inhibited Phytophthora sojae mycelial growth, formation of oospores compared with the control;compared with host soybean, non-host maize seed exudates could significantly inhibited Phytophthora sojae mycelial growth, formation and germination of oospores, germination of cysts, which indicated that the seed exudates was the critical factor to host selectivity of Phytophthora sojae and the maize seed exudates was closely related to its non-host resistance.

Impact of Crop Rotation on Pathotype and Genetic Structure of Phythophthora sojae in Fields

To estimate the impact of crop rotation on the pathotype and genetic structure of Phythophthora sojae in fields, 372 isolates of P. sojae were obtained from long-term localisation experimental fields in Heilongjiang Province of China. The hypocotyl inoculation method was used to characterize the virulence of P. sojae on 13 differential cultivars, and the amplified fragment length polymorphism（AFLP） technique was used to analyze difference in the genetic structure of P. sojae. The results indicated that an abundant diversity of genetic structures and pathotypes of P. sojae, a more uniform distribution of pathotypes and less dominance of pathotypes occurred in corn-soybean and wheat-soybean rotation fields than in a continuous soybean mono-cropping field. These findings suggested that P. sojae did not easily become the dominant race in rotation fields, which maintain disease resistance in soybean varieties. Therefore, the results of this study suggested that Phytophthora stem and root rot of soybeans could be effectively controlled by rotating soybeans with non-host crops of corn and wheat.

巨噬细胞极化相关细胞因子表达水平及其诊断膀胱癌术后大肠埃希菌感染的临床价值

目的 分析巨噬细胞极化相关细胞因子表达水平及其诊断膀胱癌术后大肠埃希菌感染的临床价值。方法 选取2018年4月-2021年3月于成都上锦南府医院泌尿外科诊治的50例膀胱癌术后大肠埃希菌尿路感染患者为感染组,分析大肠埃希菌尿液标本分离株的耐药性,另选取同期未发生术后感染的50例膀胱癌患者为非感染组,比较两组巨噬细胞极化相关细胞因子[白细胞介素(IL)-1β、IL-10、干扰素-γ(IFN-γ)及诱导型一氧化氮合酶(iNOS)]水平,采用受试者工作特征(ROC)曲线分析IL-1β、IL-10、IFN-γ和iNOS对患者术后大肠埃希菌尿路感染的诊断价值。结果 膀胱癌术后尿路感染大肠埃希菌分离株对氨苄西林、左氧氟沙星和庆大霉素的耐药率较高,对呋喃妥因、亚胺培南和妥布霉素的耐药率较低;感染组患者IL-1β、IL-10、IFN-γ和iNOS水平均高于非感染组(P<0.05);IL-1β、IL-10、IFN-γ、iNOS及联合诊断膀胱癌术后大肠埃希菌尿路感染的曲线下面积(AUC)分别为0.802、0.800、0.814、0.789和0.925。结论 膀胱癌患者术后大肠埃希菌尿路感染引起巨噬细胞极化相关细胞因子异常上调,其水平对感染具有一定的诊断价值。