Table 1 Advantages and disadvantages of plant positive-strand and negative-strand RNA virus-based vectors

Positive-strand RNA viral vector

✧ Without obvious immunogenicity in human;

✧ Consuming much less time and labor than transgenic methods;

✧ Applications in various plant species;

✧ Applications for transient expression.

✧ Easy manipulation on their simple genomes;

✧ Many available viral vectors.

♦ Used mostly on dicot plants;

♦ Incapable of accommodating large inserts.

Negative-strand RNA viral vector

✧ Simultaneous expression of multiple heterogonous proteins with high yields;

✧ Accommodation for large inserts;

✧ Allowing for genomic studies of insect vectors;

✧ Capable of co-delivery of gene editing reagents such as Cas9 and sgRNA.

♦ Very few infectious clones of plant NSR viruses can be found.