Abstract
The major threat for cassava cultivation on the Indian subcontinent is cassava mosaic disease (CMD) caused by cassava mosaic geminiviruses which are bipartite begomoviruses with DNA A and DNA B components. Indian cassava mosaic virus (ICMV) and Sri Lankan cassava mosaic virus (SLCMV) cause CMD in India. Two isolates of SLCMV infected the cassava cultivar Sengutchi in the fields near Malappuram and Thiruvananthapuram cities of Kerala State, India. The Malappuram isolate was persistent when maintained in the Madurai Kamaraj University (MKU, Madurai, Tamil Nadu, India) greenhouse, whereas the Thiruvananthapuram isolate did not persist. The recovered cassava plants with the non-persistent SLCMV, which were maintained vegetative in quarantine in the University of Basel (Basel, Switzerland) greenhouse, displayed re-emergence of CMD after a six-month period. Interestingly, these plants did not carry SLCMV but carried ICMV. It is interpreted that the field-collected, SLCMV-infected cassava plants were co-infected with low levels of ICMV. The loss of SLCMV in recovered cassava plants, under greenhouse conditions, then facilitated the re-emergence of ICMV. The partial dimer clones of the persistent and non-persistent isolates of SLCMV and the re-emerged isolate of ICMV were infective in Nicotiana benthamiana upon agroinoculation. Studies on pseudo-recombination between SLCMV and ICMV in N. benthamiana provided evidence for trans-replication of ICMV DNA B by SLCMV DNA A.
Highlights
Geminiviruses are circular single-stranded DNA viruses of the family Geminiviridae that are encapsidated in paired icosahedral particles [1]
African cassava mosaic virus (ACMV) and Sri Lankan cassava mosaic virus (SLCMV) infections result in higher levels of small interfering RNA accumulation in the recovered plants, whereas isolates that caused non-recovering infection lead to accumulation of lower levels of siRNAs.A correlation between siRNA accumulation and reduction in viral titer was reported in some cucurbits, which showed recovery from Cucurbit leaf crumple virus (CuLCrV) [17]
Southern blot analysis stage of greenhouse establishment in Madurai Kamaraj University (MKU) and the cassava mosaic disease (CMD) was confirmed by polymerase chain reaction (PCR) and Southern blot
Summary
Geminiviruses are circular single-stranded DNA (ssDNA) viruses of the family Geminiviridae that are encapsidated in paired icosahedral particles [1]. Indian cassava mosaic virus (ICMV) and Sri Lankan cassava mosaic virus (SLCMV) cause CMD in India [9,10,11]. Both ICMV and SLCMV infect Nicotiana spp. African cassava mosaic virus (ACMV) and SLCMV infections result in higher levels of small interfering RNA (siRNA) accumulation in the recovered plants, whereas isolates that caused non-recovering infection lead to accumulation of lower levels of siRNAs.A correlation between siRNA accumulation and reduction in viral titer was reported in some cucurbits, which showed recovery from Cucurbit leaf crumple virus (CuLCrV) [17]. The agroinoculation studies further showed that SLCMV DNA A could trans-replicate ICMV DNA B This is the first report of pseudo-recombination between SLCMV and ICMV
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
