Geminiviruses cause devastating crop
losses that threaten food security [1].
The geminivirus genome consists of a circular,
single-stranded DNA molecule that
becomes a double-stranded DNA replication
intermediate in the plant cell nucleus
and encodes four to seven multifunctional
proteins. Recent efforts to engineer geminivirus
resistance in crops have used several
strategies, including: (i) viral proteinmediated
resistance, in which plants are
engineered to express variants of virusencoded
proteins to decrease the effi-
ciency of a native viral protein; (ii) non-viral
protein-mediated resistance, in which
host proteins that interact with the viral
genome or proteins are mutated or
deleted, to disrupt intermediates in viral
replication or transmission; (iii) viral RNAmediated
resistance, in which viral RNA is
targeted using the host RNA interference
(RNAi) machinery; and (iv) host-derived
resistance, in which natural resistance is