NtSWEET1 promotes tobacco resistance to Fusarium oxysporum-induced root rot disease

Sugars Will Eventually be Exported Transporter (SWEET) is a newly characterized family of sugar transporters, which plays critical roles in plant-pathogen interactions. However, the function of SWEET in tobacco and its interaction with , a causal agent of root rot, remain unclear. This study aimed to dissect the function of NtSWEETs in tobacco root rot using stem bases from tobacco plants inoculated with . RNA-sequencing (RNA-Seq) analysis was performed, and the results indicated that ( ( ( , and were downregulated by infection with . The expression of , but not of , or , was suppressed at all the time points tested after inoculation with . The NtSWEET1-green fluorescent protein was localized on the plasma membrane and possessed the ability to transport glucose, fructose and galactose. Compared with the wild-type plants, RNAi plants were more susceptible to root rot, indicating that NtSWEET1 positively regulated the defense of tobacco against root rot. This study identified the role of SWEETs in tobacco and their interaction with . The results might be useful in protecting tobacco plants from root rot.