02100naa a2200265 a 450000100080000000500110000800800410001902400350006010000210009524501050011626000090022152013540023065000180158465000100160265000150161265000120162765000250163965000260166465300110169065300110170170000180171270000190173070000240174977300610177310109092016-05-24       2009    bl uuuu     u00u1 u    #d7 a10.1007/s00299-009-0673-72DOI1 aRODRIGUES, S. P.  aEffcts of the Papaya meleira virus on papaya latex structure and composition.h[electronic resource]  c2009  aSpontaneous latex exudation is the main symptom of papaya sticky (meleira) disease caused by the Papaya meleira virus (PMeV), a double-stranded RNA (dsRNA) virus. This paper describes different effects of PMeV on papaya latex. Latex samples were subjected to different histochemical tests to evaluate their chemical composition. Additionally, the integrity of the latex particles was assessed by transmission and scanning electron microscopy analysis. Biochemical and micro- and macro-element measurements were performed. PMeV dsRNA extraction was performed to evaluate the interaction of the virus with the latex particles. Sticky diseased latex was positive for alkaloid biosynthesis and showed an accumulation of calcium oxalate crystals. PMeV also increased H(2)O(2) synthesis within sticky diseased laticifers. The protein, sugar and water levels were altered, probably due to chemical changes. The morphology of the latex particles was further altered; PMeV particles seemed to be bound to the latex particles. The alkaloid and H(2)O(2) biosynthesis in the papaya laticifers indicate a papaya defense response against PMeV. However, such efforts failed, as the virus affected the plant latex. The effects described here suggest some advantages of the infection process, including facilitating the movement of the virus within the papaya plant.  aCarica papaya  aLatex  aLaticifers  aMeleira  aPapaya meleira virus  aPapaya sticky disease  aMamão  aPapaya1 aCUNHA, M. da.1 aVENTURA, J. A.1 aFERNANDES, P. M. B.  tBIOTIC AND BIOTIC STRESSgv. 28, n. 5, p. 861-871, 2009.