Analysis of the defence‐related mechanism in cucumber seedlings in relation to root colonization by nonpathogenic Fusarium oxysporum CS‐20. Issue 2 (22nd May 2014)

• Record Type: Journal Article
• Authors: Pu, Xiaoming; Xie, Bingyan; Li, Peiqian; Mao, Zhenchuan; Ling, Jian; Shen, Huifang; Zhang, Jingxin; Huang, Ning; Lin, Birun
• Is Part Of: FEMS microbiology letters. Volume 355:Issue 2(2014:Jun.)
• Page Start: 142
• Page End: 151
• Publication Date: 2014-05-22
• Subjects: Microbiology -- Periodicals; 579
• DOI: 10.1111/1574-6968.12461
• Languages: English
• ISSNs: 0378-1097

Abstract

<abstract abstract-type="main" id="fml12461-abs-0001"> <title>Abstract</title> <p>A defence response can be induced by nonpathogenic <italic>Fusarium oxysporum</italic> CS‐20 in several crops, but the molecular mechanism has not been clearly demonstrated. In the present study, we analysed the defence mechanism of a susceptible cucumber cultivar (<italic>Cucumis sativus</italic> L. 9930) against a pathogen (<italic>F. oxysporum</italic> f. sp. <italic>cucumerinum</italic>) through the root precolonization of CS‐20. A challenge inoculation assay indicated that the disease severity index (DSI) was reduced, ranging from 18.83 to 61.67 in comparison with the pathogen control. Root colonization analysis indicated that CS‐20 clearly did not appear to influence the growth of cucumber seedlings. Quantitative reverse‐transcriptase polymerase chain reaction (qRT‐PCR) revealed that CS‐20‐mediated defence response was activated by <italic>PR3</italic>, <italic> LOX1</italic> and <italic>PAL1</italic> and the pathogen‐mediated resistance response was regulated by <italic>PR1</italic> and <italic>PR3</italic>. Moreover, both nonpathogenic and pathogenic <italic>F. oxysporum</italic> were able to upregulate <italic>NPR1</italic> expression. In contrast to a pathogen, CS‐20 can activate the Ca<sup>2+</sup>/CaM signal transduction pathway, and the gene expression of both <italic>CsCam7</italic> and <italic>CsCam12</italic> increased significantly. The gene expression analysis indicated that CS‐20 strongly enhanced the expression of <italic>PR3</italic>, <italic> LOX1</italic>, <italic> PAL1</italic>, <italic> NPR1</italic>, <italic> CsCam7</italic> and <italic>CsCam12</italic> after inoculation. Overall, the defence response induced by CS‐20 can be controlled by multiple genes in the cucumber plant.</p> </abstract>