Tomato 26S Proteasome subunit RPT4a regulates ToLCNDV transcription and activates hypersensitive response in tomato

作者：Sahu Pranav Pankaj; Sharma Namisha; Puranik Swati; Chakraborty Supriya; Prasad Manoj^*

来源：Scientific Reports, 2016, 6(1): 27078.

DOI：10.1038/srep27078

Involvement of 26S proteasomal subunits in plant pathogen-interactions, and the roles of each subunit in independently modulating the activity of many intra-and inter-cellular regulators controlling physiological and defense responses of a plant were well reported. In this regard, we aimed to functionally characterize a Solanum lycopersicum 26S proteasomal subunit RPT4a (SlRPT4) gene, which was differentially expressed after Tomato leaf curl New Delhi virus (ToLCNDV) infection in tolerant cultivar H-88-78-1. Molecular analysis revealed that SlRPT4 protein has an active ATPase activity. SlRPT4 could specifically bind to the stem-loop structure of intergenic region (IR), present in both DNA-A and DNA-B molecule of the bipartite viral genome. Lack of secondary structure in replication-associated gene fragment prevented formation of DNA-protein complex suggesting that binding of SlRPT4 with DNA is secondary structure specific. Interestingly, binding of SlRPT4 to IR inhibited the function of RNA Pol-II and subsequently reduced the bi-directional transcription of ToLCNDV genome. Virus-induced gene silencing of SlRPT4 gene incited conversion of tolerant attributes of cultivar H-88-78-1 into susceptibility. Furthermore, transient overexpression of SlRPT4 resulted in activation of programmed cell death and antioxidant enzymes system. Overall, present study highlights nonproteolytic function of SlRPT4 and their participation in defense pathway against virus infection in tomato.

• 出版日期2016-6-1