Characterization of Brown Streak Virus–Resistant Cassava

Abstract

replication. Our molecular characterization of CBSD resistance in cassava offers a robust virus-host system to further investigate the molecular determinants of CBSD resistance.Ravi B. Anjanappa MPMI 4

Molecular insights into Cassava brown streak virus susceptibility and resistance by profiling of the early host response

“…No virus was detected in leaves of KBH 2006/18 scions (Fig. S2), consistent with previous results (Anjanappa et al ., ). Notably, we did not observe CBSD symptoms in any inoculated plant at 28 dag.…”

“…In a previous study investigating the cassava–CBSV pathosystem, we found that KBH 2006/18 allows the transmission of CBSVs through the stem vasculature, whereas no virus can be detected in KBH 2006/18 leaves (Anjanappa et al ., ). This suggests that the resistance of KBH 2006/18 to CBSVs involves at least restriction of intercellular virus movement from vascular tissues to mesophyll cells.…”

“…Although DEGs associated with virus movement through plasmodesmata were found only in CBSV‐infected 60444, callose deposition at plasmodesmata was reduced in 60444 and increased in KBH 2006/18, which could only be partially explained by the detected DEGs. Nevertheless, the results are consistent with the limitation of CBSV movement in KBH 2006/18 from stems into leaves (Anjanappa et al ., ). An efficacious CBSV infection of the susceptible 60444 variety thus involves a virus‐induced reduction in callose deposition at the plasmodesmata that is absent in the resistant KBH 2006/18 variety.…”

Assessment of Banana Streak MY virus-based infectious clone vectors in Musa ssp.

“…Fraile and García-Arenal (2010) defines resistance as the plant's ability to limit virus multiplication by interfering with the disease cycle. Lecoq et al (2004) supported by Anjanappa et al (2016) explains complete immunity as the plants being unable to sustain virus replication. Resistance in a broader perspective is diverse and may range from 22 interference with virus development at cell, organ, individual plant or population level.…”

“…Sometimes systemic hypersensitivity occurs (Murphy and Kyle, 1995;Tatineni and French, 2014) Resistance to virus movement between cells Virus gains entry into plant virus is sequestrated to islands of cells without induction of necrosis Plant defence mechanism confines the virus to inoculated cells (Lecoq et al, 2004) Complete resistance (immunity) There's contact between plant and virus but virus does not either gain entry or is not allowed to replicate after entry Virus may lack some necessary factors for pathogenesis or the plant's defence is strong to combat virus replication (Anjanappa et al, 2016;Kohm et al, 1993;Legnani et al, 1995) Resistance due to escape of infection mature plant escaping infection at adult stage but not earlier (same level of inoculum is used) Virus does not overcome the initial passive defence barriers of the plant (rigid cell walls) (Caranta et al, 1997) Resistance to inoculation by vectors There is no contact between plant and virus Vectors are not able to transmit the virus for some reason (Jones, 1998;Lecoq et al, 1979) While there are different types of small RNAs in plants, interestingly, they are generated by a related set of multiple genes following different pathways. There are four major sets of protein families which include Dicer-like, dsRNA binding, RNA-dependent RNA polymerase (RDRPs) and…”