Alfalfa Leaf Curl Virus: an Aphid-Transmitted Geminivirus

Area of Science:

• Plant virology
• Entomology
• Molecular biology

Background:

• The Geminiviridae family includes seven genera, distinguished by genomic and sequence characteristics, and their insect vectors.
• A proposed eighth genus, Capulavirus, was established for divergent geminiviruses lacking known vectors.
• Alfalfa leaf curl virus (ALCV) was recently discovered and initially unclassified regarding its vector.

Purpose of the Study:

• To classify Alfalfa leaf curl virus within the Geminiviridae family.
• To identify the insect vector responsible for transmitting ALCV.
• To report the first instance of an aphid-transmitted geminivirus.

Main Methods:

• Virus isolation and identification of ALCV.
• Transmission experiments using Aphis craccivora and susceptible host plants.
• Genome sequencing and phylogenetic analysis of ALCV.

Main Results:

• Alfalfa leaf curl virus was confirmed as a third member of the Capulavirus genus.
• Aphis craccivora was identified as the insect vector for ALCV.
• This study provides the first evidence of aphid transmission within the Geminiviridae family.

Conclusions:

• Alfalfa leaf curl virus represents a significant addition to the Capulavirus genus.
• The identification of an aphid vector for ALCV expands our understanding of geminivirus transmission biology.
• This finding necessitates a re-evaluation of transmission modes within the Geminiviridae family.