Molecular characterization and development of infectious clones of cotton leaf curl disease-associated begomovirus...

Cotton leaf curl disease (CLCuD), which is caused by a complex of monopartite, single-stranded DNA (ssDNA), begomoviruses and their associated satellite molecules and is transmitted by the whitefly (Bemisia tabaci), poses a serious threat to cotton production. Despite advances in reverse genetics, a rapid and reliable screening method for CLCuD resistance remains unavailable. In this study, we confirmed that the presence of Begomovirus gossypikokranense (CLCuKoV) and Betasatellite gossypimultanense (CLCuMB) components is associated with CLCuD. Infectious clones were developed using partial tandem dimer (1.4 mer) and dimeric (2.0 mer) constructs of CLCuKoV and CLCuMB, respectively, in the binary vector pCAMBIA2301. Upon agroinoculation, the recombinant clones successfully infected cotton cultivars (HS6 and RST9) and Nicotiana benthamiana, inducing characteristic vein thickening and leaf curling symptoms consistent with Koch's postulates. Using these infectious clones, we artificially screened 15 cotton genotypes under controlled conditions to evaluate the infectious clone efficiency and genotype-specific disease response. These developed infectious clones will serve as effective tools for resistance screening in cotton breeding programs and provide a platform for further studies on viral pathogenicity and host-virus interactions.

The online version contains supplementary material available at 10.1007/s12298-026-01752-0.