May 8, 2024

How Plants Activate Their Immune System Against Dangerous Pathogens in Rain

With this in mind, the scientists assumed that plants could recognize rain as a risk element for illness and respond to protect themselves from this danger in some way.

Mechanical stimuli start the concentric proliferation of intercellular calcium waves away from trichomes. Credit: Yasuomi Tada
While rain is necessary for the survival of plants, it also includes germs and other pathogens which can trigger them harm. How do plants safeguard themselves from this danger?
A recent research study by Nagoya University associates and researchers revealed that when plants are exposed to rain, hair-like structures on the leaf surface called trichomes recognize this rain as a danger aspect for triggering illness and trigger their immune system to avoid infections. These findings, published in the journal Nature Communications, might add to the development of techniques to protect plants from transmittable diseases brought on by rain.
When plants detect pathogens, they express immune-related genes to avoid themselves from being infected. With this in mind, the scientists hypothesized that plants might acknowledge rain as a danger element for disease and react to protect themselves from this threat in some way.

To discover how plants react to rain, a research study group led by Professor Yasuomi Tada and Assistant Professor Mika Nomoto of Nagoya University performed a research study utilizing Arabidopsis thaliana seedlings. When they are exposed to rain, the group began by performing RNA sequencing analyses to examine which genes are expressed in the leaves. They discovered that several major immune-related genes are expressed in response to rain, which these genes are controlled by immunosuppressive genes called CAMTAs (calmodulin-binding transcription activators).
Given that CAMTAs are controlled by calcium ions (Ca2+), the group assumed that rain serves to increase Ca2+ concentrations in cells. Thus, they investigated how Ca2+ levels in Arabidopsis leaves modification in reaction to rain by introducing GCaMP3– a gene that fluoresces green when bound to Ca2+– into the leaves. When the leaves were exposed to rain, Ca2+ levels around trichomes on leaf surface areas increased, they found that.
The outcome recommended that trichomes sense rain as a risk element and cause calcium waves (transmission of localized increases in Ca2+ to the surrounding areas) across the leaf to suspend the immunosuppressor CAMTA and consequently activate immune-related genes. To confirm this, they next performed experiments in the exact same way utilizing mutants of Arabidopsis which did not have trichomes, and the results revealed that the propagation of calcium waves was compromised in the mutants.
” From these results, we confirmed that trichomes contribute in sensing rain as a risk element and activating immune responses,” states Professor Tada. “Our findings suggest that we may have the ability to synthetically enhance plants defensive capabilities versus diseases at any time and for any length of time. Using this technology, we could make it possible to activate crops immune actions when ecological conditions are extreme adequate to perhaps trigger disease in plants, which could result in steady crop yields.”
Recommendation: “Mechanosensory trichome cells stimulate a mechanical stimuli– induced immune response in Arabidopsis thaliana” by Mamoru Matsumura, Mika Nomoto, Tomotaka Itaya, Yuri Aratani, Mizuki Iwamoto, Takakazu Matsuura, Yuki Hayashi, Tsuyoshi Mori, Michael J. Skelly, Yoshiharu Y. Yamamoto, Toshinori Kinoshita, Izumi C. Mori, Takamasa Suzuki, Shigeyuki Betsuyaku, Steven H. Spoel, Masatsugu Toyota and Yasuomi Tada, 8 March 2022, Nature Communications.DOI: 10.1038/ s41467-022-28813-8.

To discover out how plants react to rain, a research group led by Professor Yasuomi Tada and Assistant Professor Mika Nomoto of Nagoya University conducted a study utilizing Arabidopsis thaliana seedlings. They discovered that several significant immune-related genes are revealed in reaction to rain, and that these genes are regulated by immunosuppressive genes called CAMTAs (calmodulin-binding transcription activators).
They found that when the leaves were exposed to rain, Ca2+ levels around trichomes on leaf surfaces increased.