XSP10 and SlSAMT, Fusarium wilt disease responsive genes of tomato (Solanum lycopersicum L.) express tissue specifically and interact with each other at cytoplasm in vivo.

Fusarium wilt caused by Fusarium oxysporum f. sp. lycopersici (Fol) is a major fungal disease of tomato (Solanum lycopersicum L.). Xylem sap protein 10 (XSP10) and Salicylic acid methyl transferase (SlSAMT) have been identified as putative negative regulatory genes associated with Fusarium wilt of tomato. Despite their importance as potential genes for developing Fusarium wilt disease tolerance, very little knowledge is available about their expression, cell biology, and functional genomics. Semi-quantitative and quantitative real-time PCR expression analysis of XSP10 and SlSAMT, in this study, revealed higher expression in root and flower tissue respectively in different tomato cultivars viz. Micro-Tom (MT), Arka Vikas (AV), and Arka Abhed (AA). Therefore, the highly up-regulated expression of XSP10 and SlSAMT in biotic stress susceptible tomato cultivar (AV) than a multiple disease resistant cultivar (AA) suggested the disease susceptibility nature of these genes for Fusarium wilt. Sub-cellular localization analysis through the expression of gateway cloning constructs in tomato protoplasts and seedlings showed the predominant localization of XSP10 in the nucleus and SlSAMT at the cytoplasm. A strong in vivo protein-protein interaction of XSP10 with SlSAMT at cytoplasm from bi-molecular fluorescent complementation study suggested that these two proteins function together in regulating responses to Fusarium wilt tolerance in tomato. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s12298-021-01025-y.

SlHyPRP1 and DEA1, the multiple stress responsive eight-cysteine motif family genes of tomato (Solanum lycopersicum L.) are expressed tissue specifically, localize and interact at cytoplasm and plasma membrane in vivo.

Owing to rapid global climate change, the occurrence of multiple abiotic stresses is known to influence the outburst of biotic stress factors which affects crop productivity. Therefore, it is essential to understand the molecular and cell biology of key genes associated with multiple stress responses in crop plants. SlHyPRP1 and DEA1, the members of eight-cysteine motif (8CM) family genes have been recently identified as putative regulators of multiple stress responses in tomato (Solanum lycopersicum L.). In order to gain deeper insight into cell and molecular biology of SlHyPRP1 and DEA1, we performed their expression analysis in three tomato cultivars and in vivo cell biological analysis. The semi-quantitative PCR and qRT-PCR results showed the higher expression of SlHyPRP1 and DEA1 in leaf, stem, flower and root tissues as compared to fruit and seed tissues in all three cultivars. The expression levels of SlHyPRP1 and DEA1 were found to be relatively higher in a wilt susceptible tomato cultivar (Arka Vikas) than a multiple disease resistant cultivar (Arka Abhed). In vivo cell biological analysis through Gateway cloning and Bi-FC assay revealed the predominant sub-cellular localization and strong protein-protein interaction of SlHyPRP1 and DEA1 at the cytoplasm and plasma membrane. Moreover, SlHyPRP1 showed in vivo interaction with stress responsive proteins WRKY3 and MST1. Our findings suggest that SlHyPRP1 with DEA1 are co-expressed with tissue specificity and might function together by association with WRKY3 and MST1 in plasma membrane for regulating multiple stress responses in the tomato plant.