The apple scar skin disease was first re- ported 60 years ago in China ( Manchuria) with the name “Manshu-sabika-byo” (19). Twenty years later, two apple. Cause These diseases are caused by Apple scar skin viroid. Many infected cultivars of apple or pear do not express symptoms of disease. Apple scar skin viroid(ASSVd), a pathogenic RNA viroid, infects apple and pear trees. To determine if ASSVd can also infect apricot, we performed reverse.

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Supplemental data for this article can be accessed on the publisher’s website. For further confirmation, viroidliferous viroid-positive whiteflies were allowed to feed on 20 seed-grown cucumber, bean, tomato and pea plants.

Groups appld 20 whiteflies were transferred to 5 healthy cucumber plants. Because some insects are known to possess endogenous reverse transcription activity, 18 total DNA of the whitefly was isolated and tested for a possible DNA form of the viroid using PCR.

We also present evidence for the acquisition and transfer of naked RNA viroid transcripts by the insect vector under in vitro conditions and a potential role of CsPP2 in viroid sskin.

The tips were placed on racks below a tube light in temperate-controlled chambers, and groups of 20 whiteflies fed on the solution.

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Nucleic acid transfer between plants is a phenomenon which is likely to occur in many ways in nature. Published online Sep 1. Both amplification products were csar and sequenced. To our surprise, the non-specific bp amplicon was neither of whitefly origin nor a mutated shorter form of the viroid, as is known in the case of CaSVd-like RNA. Kyriakopoulou PE, Hadidi A. Some RNA species possess stem loop structures similar to tRNAs, and the existence of other unknown RNAs with such structures, which can confer increased stability, is probable.


Dot blot hybridization of the various plants inoculated through whitefly: Close Find out more. These RNAs are likely to be taken up by the whitefly and possibly transmitted to new hosts. Sundararaj, Institute of Wood Science and Technology, Bengaluru, Karnataka, India for his help in identification of the whitefly species as Trialeurodes vaporariorum.

Apple scar skin viroid naked RNA is actively transmitted by the whitefly Trialeurodes vaporariorum

Thomas Hohn, University of Basel, Switzerland for critically reading and editing the manuscript and Dr. We also demonstrated that the ASSVd-CsPP2 complex exists in vitro and in cucumber phloem, which suggests a mechanism for passage of the viroid from plants to whiteflies. A serious threat to crop production. The twenty whiteflies were then aple access to groups of 5 healthy cucumber seedlings at the one-true-leaf stage.

apple dimple (Apple scar skin viroid)

Implication of Bemisia tabaci Heat shock protein 70 in begomovirus-whitefly interactions. All of these results led us to identify a role for PP2 in viroid transfer and its translocation as a complex from the plant to the whitefly. Cold Spring Harbour Press.

Almost all fruit on an infected tree of a susceptible cultivar will show symptoms and are unmarketable. Whiteflies family Aleyrodidae are pests of herbaceous and woody plants in tropical countries and of greenhouse-grown plants in temperate climates. S3 and North-Western hybridization Fig. Side box indicates size of the different fragments bp, bp, bp, bp and bp obtained after digestion of RCA product in case of viroidliferous whitefly.

In sensitive cultivars, infection with the viroid causes significant reductions in fruit size and quality. PCR was performed as described above. Healthy plants were grown in an insect-proof growth chamber. Abstract Nucleic acid transfer between plants is a phenomenon which is likely to occur in many ways in nature.

In the susceptible cv. Plant Pathology ; Knowledge Bank home Change location. As viroid-like secondary structures are found in some plant RNAs, and PP2 is known to bind and translocate several RNAs, the results have huge implications in transfer of these RNA species vuroid plants visited by the whitefly.


Furthermore, the B biotype vector is invasive and displaces other biotypes. Here, we demonstrated that the glasshouse whitefly acts as a vector for a pathogenic viroid RNA ASSVd known to propagate in plants, yeast Avocado sunblotch viroid and Chlamydomonas Eggplant latent viroid.

app,e The DNA form of a retroviroid-like element is involved in recombination events with itself and with the plant genome. Go to distribution map Most commercial pear cultivars show no symptoms when infected with ASSVd.

Cookies on Plantwise Knowledge Bank Like most websites we use cookies. A faint band corresponding to the ubiquitin ligase mRNA was also observed when using healthy cucumber phloem. Arrows indicate the position of the monomeric linear form ml and monomeric circular form mc of viroid.

EPPO Global Database

Symptoms developed after viroid infection by whitefly- A infected bean plant showing interveinal chlorotic symptoms one month post inoculation developed due to ASSVd infection through whitefly.

Although symptoms of ASSVd are usually confined to the fruit, under certain conditions, some apple cultivars may develop leaf roll or leaf epinasty symptoms Ito and Yoshida, ; Koganezawa et al.

However, in Hebei, China, the Chinese pear P. Although the amplified fragment was not affected by this treatment, it disappeared when the sar DNA was incubated with DNase and then examined using PCR not shown.

Separation and infectivity of circular and linear forms of Potato spindle tuber viroid. Dapple symptoms, which develop nearer to harvest, usually appear on the red-skinned cultivars e. This experimental transfer also confirmed that the whitefly could take up naked RNA and transmit it, perhaps with the aid of certain whitefly proteins.