SAR vs. ISR: Two Different Ways Plants Prepare for Stress

SAR vs. ISR: Two Different Ways Plants Prepare for Stress Plant defense systems can get complicated quickly. There are hormones, biological interactions, defense compounds, signaling pathways, and a long list of acronyms involved. But sometimes the easiest way to understand a complex process is to paint a picture. Imagine you are cutting vegetables with a knife. You slip and cut your left hand. Your immediate thought is, "That knife is sharp. I need to put gloves on." You put a glove on your injured hand. More importantly, you may also put a glove on your other hand because you now recognize the threat. That is a simple picture of systemic acquired resistance, or SAR. Now imagine a different situation. Before you ever begin cutting, you notice the knife is extremely sharp. You know sharp knives can cause injuries, so you put gloves on before you start. Nothing has happened yet. You are simply prepared. That is closer to induced systemic resistance, or ISR. SAR Responds to a Threat SAR is triggered when the plant recognizes stress or an attack. A grasshopper damages a leaf. An insect feeds on the root system. Disease begins infecting plant tissue. Drought or heat creates significant stress. Something happens, and the plant responds. The plant begins signaling throughout its system and producing compounds that help it defend itself. Just like cutting one hand may cause you to protect both hands, stress in one area of the plant can trigger defensive preparation throughout the entire plant. That systemic response is important. The plant is not only reacting at the exact location of the damage. It is preparing roots, shoots, leaves, and other tissues for the possibility of additional stress. SAR is the plant recognizing a problem and responding with a relatively direct defense. ISR Prepares the Plant Before the Threat ISR is a softer, more indirect response. A healthy soil contains a diverse population of bacteria, fungi, and other organisms. As roots interact with that biology, the plant is constantly receiving signals from its environment. Some organisms may directly help the plant by improving nutrient availability or producing compounds that promote plant growth. Others may simply cause the plant to recognize that it is living in a biologically active environment. The plant begins preparing itself. It can strengthen its natural defenses, improve plant structure, and become better equipped to respond if a pathogen or stressor eventually arrives. The knife has not cut the hand yet. The plant simply recognizes that the knife is sharp. A Strong Plant Is Still the First Line of Defense One of the most basic principles of plant pathology is that a strong, actively growing plant is better prepared to handle stress. This is where plant nutrition, soil biology, and overall soil management begin connecting with plant defense. Beneficial bacteria and fungi can help make nutrients more available. Better nutrient availability can support stronger plant growth. Healthy roots can explore more soil. Stronger plant structures can create another barrier against stress and infection. Check out our Website! https://singularagronomics.com Check out our full product line here! https://singularagronomics.com/products/ Are you interested in any of our line of products, or want to learn more? Follow the link below to find a dealer closest to you! https://singularagronomics.com/contact/ Check out our Quarterly Newsletter: https://singularagronomics.com/newsle... Blog: https://singularagronomics.com/blog/ Want to become a Distributor? Email Us: [email protected] Check us out on Social Media! Instagram:   / singular_agronomics   Facebook: https://www.facebook.com/profile.php?...