Resistance Response of Chilli (Capsicum annuum L.) F1 to Fusarium oxysporum Involves Expression of the CaChi2 Gene

Abstract

Cross-breeding is a method of producing progeny with better resistance to pathogens. Resistance to pathogens usually involves pathogenesis-related (PR) proteins. Class II chitinase is an example of a defensive PR protein in plants. The class II chitinase in chilli is coded by the CaChi2 gene. In this study, we crossed susceptible with resistant chilli cultivars, analysed the F1 resistance response against pathogenic F. oxysporum, and analysed the level of CaChi2 gene expression in the F1. Data were collected using disease severity index (DSI) determination and gene expression analysis by qRT-PCR (quantitative Reverse Transcriptase Polymerase Chain Reaction). Results showed that the DSI of F1 was not significantly different from the resistant ancestor. The relative CaChi2 expression level of F1 was higher than the susceptible ancestor but not significantly different from the resistant ancestor. We concluded that the F1 can be categorised as resistant to F. oxysporum, and the CaChi2 gene is involved in the molecular defense response.

Transcriptomic profiling of susceptible and resistant flax seedlings after Fusarium oxysporum lini infection

“…In contrast to the Russian team, which used only the root tips for analysis, thus examining the local response, we decided to analyze the whole seedlings, which allowed us to recognize the systemic response of the plants to the infection. We decided to analyze two time points: 24h and 48h, because our goal was to learn the mechanisms activated in the initial stages of infection, these points were selected based on the previous analysis of chitinase gene expression, whose increase in time of Fol infection has been repeatedly confirmed both in the case of flax and other plant species [12][13][14].…”

A chitinase CsChi23 promoter polymorphism underlies cucumber resistance against Fusarium oxysporum f. sp. cucumerinum

“…Chitinases (EC 3.2.1.14), which are glycosyl hydrolases (GH) belonging to four PR protein families (PR‐3/4/8/11), are strongly induced following fungus infection in several plants (Kasprzewska, 2003; Sasaki et al ., 2006; Minic, 2008). In response to fusarium infection, several chitinase genes were strongly induced in Ananas comosus (Davis et al ., 2002), Triticum aestivum (Singh et al ., 2007), Solanum nigrum and S. elaeagnifolium (Abdallah et al ., 2017), Capsicum annuum L. (Ferniah et al ., 2018) and cucumber (Bartholomew et al ., 2019). The overexpression of chitinases in transgenic plants has also enhanced resistance against several Fusarium spp.…”