Figure 2.

NSm²¹ from American-Type but Not Euro/Asian-Type Tospoviruses Functions as an Active Inducer of Sw-5b-Mediated Cell Death.

(A) Alignment of the 21-amino acid region in NSm (NSm²¹) from American- and Euro/Asian-type tospoviruses by ClustalW.

(B) Cell death induction by various NSm²¹ mutants carrying specific amino acid substitutions. (−) to (+++++) indicate the severity of cell death on a scale of 0 to 5, as shown in Supplemental Figure 2.

(C) C118Y or T120N substitutions in NSm²¹-YFP abolish its ability to induce cell death. The leaf was photographed at 5 d postinfiltration. Expression of fusion proteins was confirmed by immunoblot analysis using YFP antibody. The sizes of proteins in kilodaltons are shown to the left of the blot.

(D) Replacement of the 21-amino acid region of TZSV NSm with TSWV induces cell death. TZSV NSm carrying TSWV NSm²¹ strongly induced cell death. TSWV NSm with TZSV NSm²¹ failed to induce cell death. Expression of chimeric NSm was confirmed by immunoblot assays using HA-specific antibody. The sizes of proteins in kilodaltons are shown to the left of the blot.