The acquisition of molecular determinants involved in potato virus Y necrosis capacity leads to fitness reduction in tobacco plants

Abstract

The prevalence of necrotic potato virus Y (PVY) in natural populations could reflect increased fitness of necrotic isolates. In this paper, the effects of the acquisition of molecular determinants (A/G 2213 and A/C 2271 ) involved in necrosis capacity on both the number of progeny produced and the competitiveness of PVY were characterized. The relationship between necrosis and fitness was tested using (i) Nicotiana tabacum cv. competitiveness. In contrast, nucleotides involved in necrotic properties were associated with decreased fitness. Finally, in the host that did not respond to infection with necrosis, the benefit associated with the PVY N -605 genetic background was higher than the cost associated with the acquisition of molecular determinants involved in necrosis capacity. The opposite result was obtained in the host responding to the infection with necrosis. These results indicate that the emergence of necrotic isolates from a non-necrotic population is unlikely in tobacco.

A complex eIF4E locus impacts the durability of va resistance to Potato virus Y in tobacco

“…PVY isolates are distributed into three biotypes, with the PVY N and PVY O biotypes separated by their ability or inability, respectively, to cause systemic veinal necrosis on tobacco (Moury, ; Singh et al , ). Although mosaic symptoms impact less dramatically the yield and quality of tobacco crops, severe leaf necrosis induced by PVY N isolates are a major concern for tobacco producers (Lacroix et al , ; Rolland et al , ; Tian et al , ).…”

The amino acid 419 in HC-Pro is involved in the ability of PVY isolate N605 to induce necrotic symptoms on potato tubers

“…In tobacco plant, it has been reported that PVY isolate with necrotic genetic background including the HC-Pro E 419 has a lower fitness (reduced size of the viral progeny) in N.tabacum cv. Xanthi and N. clevelandii than the non necrotic E/D419 mutant (Rolland et al, 2009). However, these data, collected from experiments carried out on tobacco plants, do not allow to predict the effect(s) of this determinant on the fitness of PVY in another host (e.g.…”

Identification of new Potato virus Y (PVY) molecular determinants for the induction of vein necrosis in tobacco

“…, 2007; Moury et al . , 2011; Rolland et al ., 2009; Tribodet et al ., 2005; E. Jacquot, unpublished data) has been described as a noninfectious construction when inoculated onto Nicotiana hosts. Thus, it seems that the genomic organization of the CI–6K2–NIa region of the PVY N/O SwNc_R1/R2 genome alters at least one of the critical steps of the viral cycle, resulting in a lack of production of viral progeny from the full‐length sequence inoculated onto test plants.…”

“…However, the protein structure prediction proposed by the Phyre server (Kelley and Sternberg, 2009) does not seem to be influenced by the modification of the ‘NKE’/‘DRD’ triplet in the HC‐Pro protein sequence (data not shown). Moreover, all tested point‐mutated versions of the PVY N ‐605 genetic background with single [PVY KR and PVY ED (Rolland et al ., 2009) and PVY N/O aa 339 ‘O’] and multiple [PVY N/O ‐ KE / RD (Tribodet et al ., 2005) and PVY N/O HC‐Pro‘O’/aa‘N’] modifications of the ‘NKE’ triplet are replication competent, suggesting that polymorphisms of residues N/D 339 , K/R 400 and/or E/D 419 in the HC‐Pro sequence do not drastically influence the multiple biological functions of the HC‐Pro protein (for a review, see Urcuqui‐Inchima et al ., 2001). The HC‐Pro protein has long been identified as a major symptom determinant (Atreya et al ., 1992; Gal‐On, 2000; Klein et al ., 1994; Tribodet et al ., 2005).…”

“…The change in ‘NKE’ amino acids could modify qualitative and/or quantitative parameters of the viral cycle. Indeed, it has been demonstrated that the amino acids K/R 400 and E/D 419 have an impact on the accumulation of PVY in Nicotiana hosts (Rolland et al ., 2009). Moreover, the fitness [i.e.…”