Botany Made Easy
Plant Immune Systems
Do Plants Have an Immune System?
What Do we Know about Plant Immune Systems?
We're sad to say that we don't yet have the answers to that question. We're still working on it ourselves! But we thought our readers might like to hear some of the lines of inquiry that we're looking into, some of the newest research, and some ideas of things we are trying out on our own plants.
A Healthy Plant + Good Hygiene = Better Immunity
What Might Work to Help a Plant Fight Disease?
But maybe we can start saving these plants! All hope is not lost. Here are some ideas suggested by new science research into plant immune systems. At HVH we are trying as many of them as we can, but we welcome any and all information from other hibiscus lovers on what has worked on not worked for your hibiscus.
A Growth Enhancer ~ The First line of Defense for Sick Plants
Vitamins ~ The Research Cutting Edge
Vitamin DSeveral studies have found that Vitamin D watered into the soil promotes both increased root growth and increased plant growth in plants. One study thought this was possibly due to vitamin D's effect on increasing calcium absorption in plants, just as it does in animals. But with or without added calcium, vitamin D has had a positive effect on boosting the growth and healing of stressed plants.
Vitamin CThere have been mixed results with Vitamin C. Some plants have shown increased growth and ability to fight off bacterial disease with Vitamin C added to the soil or water. Other studies showed no improvement. All plants make their own vitamin C, so scientists hypothesize that if a plant has been able to make enough vitamin C on its own, extra vitamin C won't help it. But if it has been too sick to make enough of its own, the extra vitamin C will help. Until recently we didn't even know for sure if all the vitamin C plants make actually did anything useful for them. But a 2009 study from Cornell University proved that one plant species at least can't survive without vitamin C, that it was essential for photosynthesis, and that vitamin C was highly protective against several types of stressors, including air pollution, ozone, and ultraviolet radiation. The plants that didn't have any vitamin C grew "shriveled leaves." Other studies of other plant species have also shown that vitamin C is essential for growth and has a protective effect on plants that are under different kinds of stress, such as drought.
B VitaminsB vitamins have been known to help plants resist disease for many years. More recent research confirms those earlier findings. One treatment of B vitamins has been shown to increase resistance to bacterial, viral, and fungal diseases for more than 2 weeks. All of the B vitamins researched so far seem to have a similar effect in studies on many different types of plants.
AspirinAmazingly, aspirin seems to be involved in plant immune activities at almost every level in almost every plant studied. It seems to be the near-universal plant cure-all, just as it was the near-universal human cure-all for centuries of medical history. But in plants aspirin does more than just alleviate pain. It actually blocks microbes and fights off bacterial, viral, and fungal disease. This immunity comes at a cost though. But it weakens a plant to have to make its own aspirin, and it makes the plant more vulnerable to insect attacks. This is one of the reasons that sick plants often seem to get better, then go downhill and get sicker than ever. The act of fighting off disease is very hard on plants, and the damage that follows the immune reaction may be worse than the original disease. This is why extra nutrition of every kind is so important for sick plants! They need all the help they can get when disease strikes.
- Cipollini, D., and Heil, M., 2010. "Costs and benefits of induced resistance to pathogens and herbivores in plants." CAB Reviews: Perspectives in Agriculture, Veterinary Science, Nutrition and Natural Resources.
- University of Chicago Medical Center, 2009. "Researchers Unravel Role Of Priming In Plant Immunity." ScienceDaily, http://www.sciencedaily.com/releases/2009/04/090402143449.htm.
- Gassman, W., 2009. "Too Much of a Good Thing: Understanding Plants' Overactive Immune System Will Help Researchers Build Better Crops." University of Missouri, http://munews.missouri.edu/news-releases/2009/0527-Gassman-plant-defense.php.
- Zhang, S., 2008. "How Plants Fight Back Against Pathogens Using Complex Counter Attacks." ScienceDaily, http://www.sciencedaily.com/releases/2008/03/080331172516.htm.
- Smirnoff, N., Dowdle, J., Ishikawa, T., 2007. "The role of VTC2 in vitamin C biosynthesis in Arabidopsis thaliana." Comp Biochem Phys A, 146(4), S250-S250.
- Schmelz, Eric, 2007. "Plants Under Attack: Plant Biologists Discover Plant Defenses Against Insects." USDA, http://www.aip.org/dbis/stories/2007/17106.html.
- Burkey, K., 2003. "Vitamin C Protects Stressed-Out Plants." USDA, http://www.ars.usda.gov/is/ar/archive/jan03/plant0103.htm.
- Last, R., Conkin, P., Thompson, B., and Williams, E., 1997. "Environmental stress sensitivity of an ascorbic acid-deficient Arabidopsis mutant." Proceedings of the National Academy of Sciences, http://www.news.cornell.edu/releases/Feb97/VitaminC.bpf.html.
- Li, S., Xue, L., Xu, S., Feng, H., and An, L., 2009. "Mediators, genes and signaling in adventitious rooting" The Botanical Review, 75:2, 230-247.