Abstract
The use of photosystem II (PSII) inhibitors allows simulating cascade of defense and damage responses, including the oxidative stress. In our study, PSII inhibiting herbicide metribuzin was applied to the leaf of the model plant species Chenopodium album. The temporally and spatially resolved cascade of defense responses was studied noninvasively at the leaf level by combining three imaging approaches: Raman spectroscopy as a principal method, corroborated by chlorophyll a fluorescence (ChlF) and infrared thermal imaging. ChlF imaging show time-dependent transport in acropetal direction through veins and increase of area affected by metribuzin and demonstrated the ability to distinguish between fast processes at the level of electron transport (1 − Vj) from slow processes at the level of non-photochemical energy dissipation (NPQ) or maximum efficiency of PSII photochemistry (Fv/Fm). The high-resolution resonance Raman images show zones of local increase of carotenoid signal 72 h after the herbicide application, surrounding the damaged tissue, which points to the activation of defense mechanisms. The shift in the carotenoid band indicates structural changes in carotenoids. Finally, the increase of leaf temperature in the region surrounding the spot of herbicide application and expanding in the direction to the leaf tip proves the metribuzin effect on slow stomata closure.
Highlights
Most environmental stresses, such as drought, heat, salt, UV radiation, heavy metals or cold enhance the extent of photoinhibition, which is determined by the balance between photodamage to photosystem II (PSII) and its repair [1]
The corroborative Raman bands of carotenoids within leaves of Chenopodium album were detected at 1515–1522, 1154 and 1003 cm−1
Within 24 h after the application of herbicide to Chenopodium album, the decreased intensity of the carotenoid signal was observed in the area of application (Figure 2)
Summary
Most environmental stresses, such as drought, heat, salt, UV radiation, heavy metals or cold enhance the extent of photoinhibition, which is determined by the balance between photodamage to photosystem II (PSII) and its repair [1]. We employed these non-invasive imaging techniques to monitor various biochemical and physiological responses, which are common to both PSII inhibitors effect and a range of abiotic and biotic stresses, to detect the cascade of responses, their dynamics and spatial distribution within the plant leaves. These techniques may find application in high throughput screening of genotypes resistant to abiotic or biotic stress—plant phenotyping, in understanding and stimulating the processes leading to induction of defense mechanisms, or in optimizing the herbicide application
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
