Distribution and pathway for phloem‐dependent movement of Melon necrotic spot virus in melon plants

Abstract

The translocation of Melon necrotic spot virus (MNSV) within tissues of inoculated and systemically infected Cucumis melo L. 'Galia' was studied by tissue-printing and in situ hybridization techniques. The results were compatible with the phloem vascular components being used to spread MNSV systemically by the same assimilate transport route that runs from source to sink organs. Virus RNAs were shown to move from the inoculated cotyledon toward the hypocotyl and root system via the external phloem, whereas the upward spread through the stem to the young tissues took place via the internal phloem. Virus infection was absent from non-inoculated source tissues as well as from both shoot and root apical meristems, but active sink tissues such as the young leaves and root system were highly infected. Finally, our results suggest that the MNSV invasion of roots is due to virus replication although a destination-selective process is probably necessary to explain the high levels of virus accumulation in roots. This efficient invasion of the root system is discussed in terms of natural transmission of MNSV by the soil-borne fungal vector.

Promotion of flowering and reduction of a generation time in apple seedlings by ectopical expression of the Arabidopsis thaliana FT gene using the Apple latent spherical virus vector

“…Hybridization was performed with 500 ll hybridization solution (50% formamide, 6 9 SSC, 3% SDS, yeast tRNA 0.1 mg ml -1 ) as described by Gosalvez-Bernal et al (2008) and a DIG-labeled RNA probe complementary to positions 1418-2111 of ALSV-RNA2 (100 ng per slide) at 55°C for 20 h. Washing after hybridization was conducted as described by Takagi et al (2008). Hybridized probes were detected by sheep anti-DIG conjugated to alkaline phosphatase (Roche Plant Mol Biol (2011) 75:193-204 195 Molecular Biochemicals) diluted 1:500 in buffer 1 containing 0.2% Tween 20 for 30 min.…”

Seed and pollen transmission of Apple latent spherical virus in apple

“…The sections were treated with proteinase K (1.5 lg/mL) and fixed in 4% (v/v) paraformaldehyde. Hybridization was performed as described by Gonsalvez-Bernal et al (2008) at 48°C for 30 h with 200 lL hybridization solution [50% (v/v) formamide, 69 SSC, 3% (w/v) SDS, 0.1 mg/mL yeast tRNA] and DIG-labeled RNA probes complementary to positions 1418-2111, 2111-2618, and 2619-3197 of ALSV-RNA2. After hybridization, washing was conducted as described by Takagi et al (2008).…”

Relationship Between Plant Vascular Architecture and Within-Plant Distribution of ‘Candidatus Liberibacter solanacearum’ in Potato

“…Although results of previous studies indicated that the movement of phloemlimited viruses is restricted by vascular connectivity among leaves (Leisner et al 1992;Andrianifahanana et al 1997;Gosalvez-Bernal et al 2008), the movement of phytoplasmas, which are phloem-limited bacteria, does not appear to be limited by vascular architecture (Kuske and Kirkpatrick 1992;Constable et al 2003;Christensen et al 2004). Instead, phytoplasmas tend to accumulate in source leaves, perhaps because they attach to the sieve-element membrane, are retained in the sieve pores, or are self-mobile (Christensen et al 2004).…”