Required for the restriction of long-distance movement of the pathogenic tobacco etch virus (TEV) without causing a hypersensitive response or inducing systemic acquired resistance. Self-interacts. Interacts with RTM3. Soluble protein present in sieve elements in a punctate pattern of 1 to 2 um spheres. Expressed at low levels exclusively in phloem-associated cells (e.g. sieve elements and adjacent cells). Regulated by the transcription factors NAC045 and NAC086. Susceptible to systemic infection by tobacco etch virus (TEV). Belongs to the jacalin lectin family. Has been shown to be inactive in cv. Ler-2 (AC D9UBI3) and cv. Bl-1, cv. C24 and cv. Ct-1 (AC D9UBG0) due to naturally occurring sequence variation in these strains. The sequence shown is from strain cv. Columbia.