I was wondering about disease resistance. Can roses become disistant after a while to any fungus? Is it possible that they get it when they are young but trying to fight it and somehow remember the disease and rhen after a second or rhird attack they are less infected or evwn immune ro that disease? A bit so to say, like our human body works. Does anyone knows of such a mechanism in roses or any other plants?
I’m not aware if the mechanisms for acquired immunity exist in the plant kingdom, but I would be inclined to say that if such were to exist, antique roses would be pretty bullet-proof.
And, many are…where they are suited. Those grown where they aren’t are often horrid. Rugosas, Damasks, Centifolias are horrible in long, hot, dry, alkaline areas for black spot and rust. As if the heat lasts longer than the foliage can remain juvenile and healthy.
Back a few decades ago someone named Joe Kuc (not sure of spelling last name) discovered systemic acquired resistance in plants. He was a plant pathologist in Kentucky and came here to give a talk in our PlPath dept. I visited with him for an hour or so. In the instance he was studying the resistance was transmitted by salicylic acid. That’s where the idea of giving aspirin to plants came from. There are quite a few different signals known now. RNA molecules are some of them that move from one leaf to another. Yes a plant may remember, sometimes, to some extent under some conditions.
Innate immunity is pretty good, where sequences that match certain viruses, are stored in the genome of the organism, for instance bacteria, so that it can react and block the virus replication. That’s where the whole CRISPR gene cutting system came from. I don’t know of actual evidence for epigenetic changes in the plant genome to make it more resistant to a disease that it was once exposed to. But I see nothing to prevent such an effect.
For sure, response to herbivores goes from leaf to leaf. Even from plant to plant via methyl jasmonate ( a volatile fragrance of jasmine). Fungi that do damage to the leaf do it in different ways and stimulate different profiles of volatiles to be made and released. Prior exposure to insects makes the plant more resistant to a second attack of that insect, by making anti-feedants. I don’t know of the same effect for fungi. It is a bit tricky to study.