Construction and Analysis of SSH-cDNA Library from Leaves of Susceptible Rubber Clone Resistant to Powdery Mildew Induced by BTH

Abstract

To understand the mechanism of benzothiadiazole (BTH)-induced susceptible rubber clone resistance to powdery mildew on gene level, a differentially expressed cDNA library was constructed by suppression subtractive hybridization (SSH) with rubber Reyan 7-33-97 clone. The constructed cDNA library was high integrity through detection of the critical processes of SSH, such as efficiency of adaptor connection, subtraction and conversion, as well as the type of recombinant genes. The positive rate was 99% after identification with random 400 white spots. The size of the cDNA clone inserted fragments was various but most in 400 bp -1000 bp. There were 23 cDNA sequences matching the function of energy and basic metabolism, signal transduction, membrane and transport, secondary metabolism and so on after detection of the 42 positive clone sequences selected randomly from the cDNA library and comparison on nucleic acid sequences in Genbank. 7 ESTs were logged in Genbank and accession numbers were GW873071 and GW874604-GW874610. The results implicated that BTH could effectively induced rubber tree resistance to powdery mildew through increasing expresses of defense-related genes in leaves of rubber tree susceptible clone. It should provide a new approach for rubber disease management.

Powdery mildew disease of rubber tree

“…It also provides the necessary information required for further study on the pattern of expression and signal transduction pathway of rubber tree defence genes (Luo et al. ).…”

“…This may result in the separation of mildew-resistant genes from those of the rubber tree (Chen et al 1994). The process of disease resistance in plants consists of a series of reactions, for example signal recognition, single transduction, defence reaction activation and the expression of defence gene (Luo et al 2013). These reactions have been broadly used to understand the differences of gene expression in plant disease resistance and reaction responses to environmental stress (Xiong et al 2001;Ouyang et al 2007).…”

“…This indicates that BTH could effectively induce resistance to rubber powdery mildew disease. It also provides the necessary information required for further study on the pattern of expression and signal transduction pathway of rubber tree defence genes (Luo et al 2013).…”