Authors: Radwan, Deya Eldeen Mohammed; Lu, Guoquan; Fayez, Khalaf Ali; Mahmoud, Sabry Younis.

Authors affiliation: College of Agriculture & Biotechnology, Zhejiang University, Hangzhou, Peop. Rep. China.

Published in: Journal of Plant Physiology (2008), 165(8), pages 845-857.

Abstract: "In this study, morphol., ultrastructural and physiol. modifications of faba bean (Vicia faba cv. Giza 461) leaves in response to bean yellow mosaic virus (BYMV) infection and salicylic acid (SA) treatments were examd. Under BYMV stress, leaves showed symptoms including severe mosaic, mottling, crinkling, size redn. and deformations. Three weeks after virus inoculation, photosynthetic rate, pigment contents and transpiration rate were significantly reduced in response to BYMV infection. Ultrastructural investigations of BYMV-infected leaves demonstrated that most chloroplasts with increased stromal area became spherical in shape and some lost their envelopes, either partially or totally. The internal structures of chloroplast, grana and thylakoids were dilated. Two kinds of inclusions were detected in BYMV-infected leaves: straight or slightly curved bands sometimes coiled or looped at the end, and electron opaque crystals with varied shapes. BYMV-infected cells showed lower chloroplast no. in comparison to the control. Spraying of SA on faba bean leaves helped to reduce or prevent the harmful effects produced after virus infection. Application of 100 .mu.M SA three days before inoculation restored the metab. of infected leaves to the levels of healthy controls. SA treatment improved plant health by increasing the photosynthesis rates, pigment contents and levels of other parameters studied similar to control values. Moreover; SA treatment increased plant resistance against BYMV. This was obsd. through induction of chloroplast no., redn. in percentage of infected plants, and decrease in disease severity and virus concn. of plants treated with SA prior to BYMV inoculation. Cells of SA-treated samples showed well-developed chloroplasts with many starch grains and well-organized cell organelles. The present results provide an overview of the neg. effects on faba bean leaves due to BYMV infection from physiol. and subcellular perspectives.
Also, a role of SA involved in induction of resistance against BYMV infection in bean plants is discussed."

http://findarticles.com/p/articles/mi_qa4069/is_200405/ai_n9441990/

http://www.ingentaconnect.com/content/cryo/cryo/2009/00000030/00000003/art00002

What from I understand of the process for someone in my climate, zone 5, lots of rain in the fall helps my roses better than anything. A little aspirin in the spring diluted in some water might help the less sturdy roses and a little dose in the middle of summer may help with disease problems.

Next summer if I notice some roses in stress I will give them a dose just to see what happens. can't hurt too much if it isn't mixed too strong. Worth a try.

Valerie

http://arjournals.annualreviews.org/doi/abs/10.1146/annurev.phyto.050908.135202

Can't locate the source, but it was an amateur experiment in enhancing disease resistance.

Authors: Lewsey, Mathew G.; Carr, John P.

Authors affiliation: Department of Plant Sciences, University of Cambridge, Cambridge, UK.

Published in: Journal of General Virology (2009), volumn 90, Issue 12, pages 3010-3014.

Abstract: ""Salicylic acid (SA)-mediated resistance and RNA silencing are both important plant antiviral defense mechanisms. To investigate overlap between these resistance phenomena, we examd. the ability of mutant Arabidopsis thaliana plants lacking DICER-like (DCL) endoribonucleases 2, 3 and 4 to exhibit SA-induced defense. We found that in dcl2/3/4 triple mutant plants, treatment with exogenous SA stimulated resistance to two pos.-sense RNA viruses: cucumber mosaic virus and tobacco mosaic virus. We conclude that DCLs 2, 3 and 4, which are the predominant DCL endoribonucleases involved in silencing of pos.-sense RNA viruses, are not required for effective SA-induced resistance to these viruses. However, the findings do not exclude RNA silencing from making a contribution to SA-mediated resistance in wild-type plants."